Research Digest

ERD Examine.com Research Digest

Issue 7 ◆ May 2015 1 Table of Contents 05 Going nuts over infant peanut exposure Randomized trial of peanut consumption in infants at risk for peanut allergy 13 How the Food Industry Spins Science to Fit Its Agenda By Andy Bellatti, MS, RD 16 Non-celiac gluten sensitivity: much ado about something? Small Amounts of Gluten in Subjects with Suspected Nonceliac Gluten Sensitivity: a Randomized, Double-Blind, Placebo-Controlled, Cross-Over Trial 23 Baby probiotics for prevention of ADHD and Asperger’s A possible link between early probiotic intervention and the risk of neuropsychiatric disorders later in childhood: a randomized trial 31 Putting the “D” in Death A reverse J-shaped association between serum 25- hydroxyvitamin D and cardiovascular disease mortality – the CopD-study 40 Eggcellent Eggs: Is it safe for people with diabetes to eat a lot of eggs? The effect of a high-egg diet on cardiovascular risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) study—a 3-mo randomized controlled trial 46 Do BCAAs and arginine prevent central fatigue during exercise? Branched-chain amino acids and arginine improve performance in two consecutive days of simulated handball games in male and female athletes: a randomized trial 52 HMB-elly be gone β-Hydroxy-β-methylbutyrate (HMB) supplementation and resistance exercise significantly reduce abdominal adiposity in healthy elderly men 58 Spicing up your workout Curcumin supplementation likely attenuates delayed onset muscle soreness (DOMS) 65 INTERVIEW: Shawn Wells, MPH, RD 71 Ask the Researcher: James Heathers, Ph.D.

2 From the Editor Does “natural” matter in food and nutrition? inform what you eat. You MOST CERTAINLY don’t have to be anyone’s definition of “paleo”. Humans can eat a vari- I don’t think natural versus processed is just a fluff issue. ety of foods and thrive. Different people have astoundingly Many people use heuristics to guide how they eat, whether different reactions to food, due to their gut microbiomes, they know it or not. It’s hard for most people (Soylent aficio- disease states, and many other factors. nados excepted) to envision a mostly processed/powdered diet being healthier than a diet composed mostly of less Why does this matter for ERD and nutrition research in processed plants and animals. general? Well, it’s very easy to get caught up in research details and miss the big picture of health. Yes, heating toma- For ERD, we occasionally point out that certain nutrients toes increases lycopene absorption. Yes, piperine increases and supplements don’t need to come in pill form, and can absorption of curcumin. But so many people obsess over be ingested through food. But constantly telling people how details while missing the truly high impact habits, like cir- to eat sounds preachy from most anybody, and we are pretty cadian rhythm entrainment and stress reduction. Avoiding much evidence-conveyors rather than gurus. That doesn’t yo-yo dieting and enjoying wholesome meals is a good pre- mean we don’t have opinions on an individual level though. requisite to supplementation in general. And my personal opinion is that natural does probably matter. And while evidence is our bread and butter, know the lim- I don’t mean the literal definitions of natural and processed, itations of evidence. Just because research suggests that which gets into annoying semantics and downward spirals artificial sweeteners may be fairly safe, don’t take that as of argumentation. Yes, cutting a carrot is processing it. Yes, an excuse to drink two Diet Cokes every day for thirty applying heat can be considered processing. I’m not talking years. From reading ERD, you should be well aware that about gray areas though. This is about a smoothie versus a study findings don’t equal truth. Although evidence is Diet Coke. Pastured beef versus a zero carb protein bar with mixed, we’re just starting to find that artificial sweeteners thirty ingredients. may adversely impact the gut microbiome. While nutrition research is complex, nature is magnitudes of order more Don’t get me wrong: artificial foods can be magically deli- complex. It’s probably a good idea to consider both when cious. If you have enough self-control, Cheetos can be making decisions for your own health. worth every flourescent orange dusted finger that needs washing before using your laptop. A little bit, or even a moderate amount every once in a while, isn’t likely to be terrible for you.

But that’s a guess. There will be no randomized trials on Cheetos (I think). What there is though, is history. Many thousands of years of humans eating food that can help Kamal Patel, Editor-in-Chief

3 Contributors Researchers

Trevor Kashey Alex Leaf Courtney Silverthorn Zach Bohannan Anders Nedergaard Jeff Rothschild Ph.D(c) M.S(c) Ph.D. M.S. Ph.D. M.Sc., RD

Editors

Gregory Lopez Pablo Sanchez Soria Kamal Patel Pharm.D. Ph.D. M.B.A., M.P.H., Ph.D(c)

Reviewers

Arya Sharma Natalie Muth Stephan Guyenet Sarah Ballantyne Katherine Rizzone Spencer Nadolsky Ph.D., M.D. M.D., M.P.H., RD Ph.D. Ph.D. M.D. D.O.

Mark Kern Gillian Mandich Ph.D., RD Ph.D(c)

4 Going nuts over infant peanut exposure Randomized trial of peanut consumption in infants at risk for peanut allergy Introduction Peanut allergies are becoming more widespread across the globe. In the United States, up to 1.4% of the population, or as many as 4.4 million people have a peanut allergy. Peanut exposure is one of the leading causes of allergy-related deaths due to anaphylax- is, a set of symptoms that can include facial and oral swelling, difficulty breathing, a dangerous drop in blood pressure, and cardiac arrest. Other less severe symptoms include itchy skin and mouth, hives, and gastrointestinal distress.

Unlike some other food allergies, like milk, soy, and egg, a peanut allergy rarely lessens with age. While there has been a lot research into possible therapies, there is currently no treatment other than complete avoidance, which requires hypervigilance in case of cross-contamination of other foods, leading to trace amounts of peanut in foods that would otherwise be assumed as safe. Many current research efforts focus instead on ways to prevent the development of severe allergies like this one. Researchers discovered that dietary antigens (foreign substanc- es that trigger the immune system to respond) for allergenic foods can pass through the placenta to the fetus, as well as pass through breast milk to an infant. Based on this finding, they hypothesized that preventing this early exposure would reduce the incidence of food allergies.

5 For most of the first decade of the 21st century, women Figure 1 - Peanuts: from snack darling were advised to avoid possible allergy triggers like peanuts, to object of constant vigilance dairy, and egg during their pregnancies, as well as to avoid feeding them to their infants. In spite of these efforts, epide- miological data show that the incidence of allergies actually increased. In fact, a meta-analysis of studies following children whose mothers had avoided dietary allergens found that those children developed allergies at approximately the same rate as children whose mothers did not adhere to the dietary recommendations. As a result, the recommendation to avoid dietary allergens during pregnancy was later aban- doned. Figure 1 notes some milestones from the past few decades with regards to peanut allergy.

The increase in allergy rates in response to avoiding certain foods raises the question of whether deliberate exposure to potentially allergenic foods could reduce the incidence of allergies. This study was designed to investigate this question in the context of peanut allergies in infants.

The number of people with a peanut allergy is increasing worldwide, which can result in a serious and sometimes life-threatening allergic reaction. Previous recommendations for mothers to avoid allergens during pregnancy and breastfeeding did not prevent the rise in allergies in children. The purpose of this study was to see if consumption of peanuts at an early age might help prevent development of peanut allergies in children.

Who and what was studied? Infants from four to 11 months who had already been diagnosed with severe eczema and/or egg allergy were included in this study. Because the study was on infants, and because of the possibility of serious allergic reactions, the trial was conducted as an ‘open-label’ study, rather than a blind or double-blind study. Both the researchers and the parents knew whether or not their child would receive the peanut snack.

The infants were divided into two groups on the basis of a Source: Sicherer et al., J Allergy Clin Immunol. 2010 skin prick test (SPT) with peanut allergens. About 15% of

6 the infants in the study were assigned to one group after an Parents were provided with the peanut snacks to feed to initial positive SPT, defined as a skin wheal, or localized their child, with the option of substituting an equivalent region of redness and swelling, between one to four milli- amount of peanut butter instead. The researchers conducted meters. The 80% of the infants with a negative initial SPT in-person follow-up appointments at 12, 30, and 60 months were assigned to a second group. Infants with wheals larg- into the study. At each appointment, children were tested er than four millimeters were excluded from the study for for reactions to the peanut protein SPT. Researchers also safety reasons, as they would be expected to already have measured the levels of peanut-specific antibodies. Periodic allergic sensitivity to peanuts. food questionnaires were used to confirm adherence to the assigned protocol, and at the end of the study some partici- Within each group, the infants were randomized to either pants had dust collected from their bedrooms to test for the receive a peanut snack at least three times a week, or presence of peanut protein. instructed to avoid consuming any peanut products. For safety reasons, before the study actually began, the research- If the child had no positive SPTs at 60 months and no other ers performed one final screening test. They had each infant reported symptoms of allergies, he or she received a final assigned to the consumption groups actually consume oral challenge of five grams of peanut protein. Other chil- peanut protein, in a single dose if they had a negative SPT, dren, who had positive SPTs, or other signs of suspected or in small incremental doses if they had a positive SPT. Six allergies, received their final peanut protein challenge in infants in the positive SPT group and one in the negative small incremental doses. SPT group had allergic reactions to the baseline dose of peanut protein and were moved from the peanut consump- Researchers followed the infant participants until age tion group to the peanut avoidance group. five, and tested periodically for skin reactions to peanut protein. A final oral challenge was conducted at the end The study randomly assigned infants under 11 months of the study to assess the development of peanut allergies. of age to either consume or avoid peanuts, but any infant who showed signs of an allergic reaction after the first oral exposure was moved from the peanut consumption What were the findings? group to the peanut avoidance group. The researchers first evaluated the larger intent-to-treat group (see sidebar). In both the positive and negative Because the study was on infants, and because of the possibility of serious allergic reactions, the trial was conducted as an ‘open-label’ study, rather than a blind or double-blind study.

7 Intent-to-treat and SPT groups, the researchers observed a significant decrease in the per-protocol analyses development of peanut allergies, as observed in the final oral challenge. For the group that had a negative SPT at the start of the study This study conducted two analyses of (530 infants), 13.7% developed an allergy to peanuts if they avoided the patient data. The first, Intent-to-Treat peanuts for the duration of the study, compared to only 1.9% of the analysis, examines all participants on infants who consumed peanuts. This is equal to an 86% reduction in the basis of their initial randomization, relative risk. informally referred to as “once randomized, always analyzed.” This included the In the group that had a positive SPT at enrollment (98 infants), 35.3% seven children that were randomized to developed a peanut allergy if they avoided peanuts, and only 10.6% the peanut consumption group but had did if they consumed peanuts. This means that even the SPT-positive allergic reactions in the oral screen and group saw a 70% decrease in their relative risk. The inclusion of the were removed from that group, as well 12 participants with missing data in the intent-to-treat analysis using as participants who had inconclusive or a worst-case assumption (subjects who consumed peanuts are pre- incomplete data. A computer algorithm sumed to be allergic, and those who avoided peanuts are presumed to was used for the latter group to deter- be non-allergic) did not change the prevalence data significantly. mine whether the participant would be presumed to have a peanut allergy, based There are two ways to convey an increase or decrease in risk. One of on clinical history and other factors. these methods sometimes sounds much more dramatic than the other. Intent-to-Treat analyses mirror real life Absolute risk is the actual change in the incidence of the factor being more closely, as they account for drop- studied. Relative risk is the ratio of the risk level of the test group outs due to adverse events or difficulties compared to the risk level of the control group. with the treatment. However, treatments may appear to be less effective if the data If the control group has a risk of 2% and the test group has a risk of is diluted with people who simply didn’t 1%, then there is a 1% reduction in the absolute risk and a 50% reduc- follow the prescribed treatment. tion in the relative risk. Sometimes small changes in the absolute risk can be magnified by reporting a large change in the relative risk, par- The second, Per-Protocol analysis, includ- ticularly when studies are reported by the media, but it’s important to ed only the participants that followed know both numbers. the protocol to which they had been assigned. Children who were removed The slightly smaller per-protocol group analysis showed an even more from the consumption group, as well drastic difference. Here, a similar percentage of participants devel- as children who did not adhere to their oped allergies in the avoidance groups: 13.9% with a negative SPT and consumption or avoidance protocol and 34% with a positive SPT at screening. However, in the consumption children who dropped out for various rea- groups only two participants with negative SPTs (0.4%) developed a sons, were excluded from this analysis. A peanut allergy, and no subject with a positive SPT did. Per-Protocol analysis can show a more convincing result because people who The average wheal size measured in the SPTs for children in the pea- didn’t follow the treatment are excluded. nut avoidance group increased at each follow-up visit, while there When a paper provides only Per-Protocol was no change for the children who had consumed peanuts regularly. results despite substantial dropout or Within the consumption group, the largest wheal measured was about noncompliance, be wary. 8 five millimeters, while in the avoidance group a number of Figure 2: Adverse events in wheals were much larger, up to 22 millimeters. peanut consumption group

Unsurprisingly, 99% of the study population reported at least one adverse event over the course of the four-year study. Many of these were likely unrelated to the study itself, though there was a slightly higher rate of non-serious adverse events in the peanut consumption groups, shown in Figure 2. These primarily included upper respiratory tract and skin infections, stomach viruses, and mild episodes of hives. This increase was found to be statistically significant, but it’s possible that these events could be due to the fact that the trial was unblinded. Parents who knew that their child was consuming peanuts could have been more likely to report their child’s symptoms.

There was a slight increase in the rate of adverse events among children who were consuming peanuts, possibly because their parents were more alert to the presence of symptoms.

In addition to physical symptoms, the study also measured levels of peanut-specific antibody development. IgG, IgE, and IgG4 levels were tested at baseline and at each follow-up appointment. Development of IgG antibodies indicates exposure to a particular antigen, and increased levels of IgE antibodies are a marker of the allergic response. The level of IgG4 antibodies alone, and the ratio of IgG4 antibodies to the level of IgE antibodies, reflect the level of immune modulation, or how well controlled the immune system is in response to a specific antigen. While the average IgE antibody level increased over time in both the consumption and avoidance groups in a similar fashion, nearly all of the children who developed allergies by 60 Additionally, the ratio of IgG4 to IgE in nearly every child months had IgE levels above the group average. who developed a peanut allergy was below the group mean. This indicates that the immune system modulation effects The fact that the average levels of peanut-specific antibodies of the IgG4 antibodies were not overcoming the pro-allergy were significantly higher in the consumption group than effects of the IgE antibodies. in the avoidance group suggests that oral exposure may be causing the immune system to modulate itself appropriately.

9 Children who avoided peanut consumption were about five times more likely to develop a peanut allergy, had more severe skin reactions to a test exposure, and showed increased antibody development and decreased immune [...] this study tolerance to peanut antigens than children who consumed peanuts regularly. shows that early

What does the study really exposure may tell us? be able to put This study showed a large, statistically significant reduction in the development of allergic sensitivities to peanuts when the brakes on allergy-prone infants consumed peanut products regularly, compared to avoiding peanut products for the first several the immune years of life. The authors do note that the main weakness of the study is the lack of blinding and a placebo control. The impact of this aspect of the trial design is minimized system, but it by using an objective measurement, skin wheal size, rather than subjective measurements, like severity of symptoms. wasn’t designed In fact, because the parents probably expected more side effects if their children were assigned to the peanut groups, to show whether the lack of blinding would be expected to produce a bias against the results that were actually seen: an observed pro- treatment can tective effect of peanut allergen exposure. induce the Overall, the study provides support for early peanut exposure for both primary prevention of allergies in children immune system who are not already sensitized to peanut protein, and secondary prevention in children who are showing sensitivity to peanuts with increased antibody levels and skin to make a u-turn responses, but have not yet developed an allergy. It does not, however, offer any support for for the idea that pea- to reverse an nut allergen exposure may be a viable treatment strategy for children who have already become allergic to peanuts. existing peanut In other words, this study shows that early exposure may be able to put the brakes on the immune system, but it allergy. wasn’t designed to show whether treatment can induce the immune system to make a u-turn to reverse an existing peanut allergy.

10 A potentially important confounding factor that is unfortu- diet. This study was published by the same research group, nately missing from the study demographics is whether the and led to the hypothesis for this clinical trial. mothers of the study participants had consumed or avoided peanuts during their pregnancies. The previously cited for- Researchers suspect that while oral consumption may pro- mer dietary recommendations not only advocated for infant mote immune tolerance, topical exposure may be the factor avoidance of allergenic foods, but also for maternal avoid- that induces allergic sensitization. This “dual allergen expo- ance during pregnancy and breastfeeding. A recent analysis sure” hypothesis is depicted in Figure 3. Another study by of multiple clinical trials did not find that infants had a this research group observed that an increased environmen- decreased allergic sensitivity to milk or eggs when their tal exposure to peanut allergens without a corresponding mothers avoided those foods during pregnancy. It would be oral exposure was associated with higher risks of developing interesting to know whether the consumption or avoidance a peanut allergy. This study used dust samples from some of peanuts by the mothers of participants in this study cor- of the children’s bedrooms to confirm whether the families related with the baseline and post-intervention SPTs. had avoided or introduced peanuts as they were directed. While the average peanut protein levels were about 20 times higher in the consumption families’ homes than in the This study provides evidence that early exposure to pea- avoidance families’ homes, there were still detectable levels nuts can help prevent the development of peanut allergy in some of the homes where children had been instructed for at-risk infants, although it does not indicate whether to avoid peanuts. These children were likely receiving some peanut exposure can reverse an allergy that already exists. level of environmental exposure without any oral exposure to induce immune tolerance. On the other hand, children who consumed peanuts had sufficient oral exposure to The big picture counteract their increased environmental exposures. There have been previous observational correlations that cultural populations which traditionally consume more Another allergy aspect that needs to be studied is wheth- peanuts and introduce children to these foods at an earlier er any potential effects of desensitization persist. A study age have a lower rate of peanut allergies than cultures that conducted on slightly older children who had been treated do not typically consume peanuts as a normal part of their with an immune-based therapy for egg allergy showed that

Figure 3: The dual-allergen exposure hypothesis

Adapted from: Lack, J Allergy Clin Immunol. 2012 11 less than a third of the participants for whom the treatment nut allergies in the absence of oral exposure, this alone may worked passed another food challenge test two years later. explain the increased IgE antibody levels.

Would exposure to peanuts work for all infants? Other observational studies support the idea that the The researchers noted that no healthy, low-risk infants early introduction of peanuts will decrease the risk of without a history of other allergies were included in the developing a peanut allergy. More research is needed to study population, so these results aren’t applicable across determine if consumption must be maintained in order the board. Additionally, very high risk infants who had for the immune system effects to continue. severe reactions to the SPT (characterized by skin wheals greater than four millimeters) were also excluded from the study. These infants were already displaying signs of a pea- Frequently asked questions nut allergy, so the prevention study would not have applied Would a short term exposure to an allergen provide lifelong to them, though it’s possible that they could have seen some tolerance? benefit from an earlier intervention. The study population To answer this question, the length of this “short term” was also predominantly (roughly 75%) Caucasian. A more exposure needs to be quantified. The study under review diverse study population could provide additional informa- used a four-year exposure period. It’s possible that a short- tion about how applicable these results might be to infants er exposure duration can have similar effects, but it’s also as a whole. possible that the exposure has to be consistent and longer or even permanent, in order to prevent the development of inappropriate immune responses. The study described What should I know? Contrary to previous dietary recommendations of the early here is continuing with a follow-up trial that is designed 2000s, which advised parents to prevent their children from to evaluate the persistence of the effects over one year, in being exposed to allergenic foods in infancy, infants who which the participants are going to avoid peanut exposure. consumed peanuts regularly developed peanut allergies The study will also assess the development of other allergic at a significantly lower rate than those who avoided pea- diseases, including other food allergies and asthma, which nuts, even though the infants studied were considered an is more challenging to diagnose before age five. When the at-risk population due to other pre-existing allergies. The additional data is published, we may eventually be able to decreased allergy risk was observed consistently, regardless provide a more reliable answer to this question. of whether the infant had a positive skin reaction to peanut protein at the start of the study. Why did peanut-specific IgE antibody levels increase in both groups of children? One last note as a public safety announcement: parents should Complete avoidance of all peanuts in all forms for years is not actually give whole peanuts to very young children, due to almost impossible in the real world. Families that agreed choking hazards. Ground up nuts and thinner peanut butters to have dust samples collected and tested for the presence may be better options. And always discuss these (extremely of peanut protein had significantly higher levels than those important) choices with the child’s physician. detected in the peanut avoidance group, but dust from ◆ the peanut avoidance group still tested positive for some peanut protein. Furthermore, a few of the measurements If you are thinking about pregnancy or know someone who in the avoidance group were above the average of the con- is, this study may have a huge real-world impact. To discuss sumption group. If we take into account that environmental it more, visit the ERD Forum on Facebook. exposure is suspected to promote the development of pea-

12 By Andy Bellatti, MS, RD

Scrutiny of food industry practices and unhealthy products has ramped up over the last decade thanks to the tireless work and vigilant eyes of public health and nutrition advocates. While this is good news for the public, it’s not a rosy outlook for the food industry and its bottom line. In an effort to combat these advocacy efforts, the industry has honed two skills: sponsoring research and spinning science.

Sponsored research provides the food industry with two benefits. First, it creates an opportunity to frame science in a way that is beneficial to their product line and simultaneously deflects criticism. Second, it provides an easy bibliography that the industry can tap into the next time it is criticized.

Recently, the Public Library of Science Medicine published a research article titled “Financial Conflicts of Interest and Reporting Bias Regarding the Association between Sugar-Sweetened Beverages and Weight Gain: A Systematic Review of Systematic Reviews.”

Among the findings:

“The researchers identified 18 conclusions from 17 systematic reviews that had investigated the association between SSB consumption and weight gain or obesity. In six of these reviews, a financial conflict of interest with a food industry was disclosed. Among the reviews that reported having no conflict of interest, 83.3% of the conclusions were that SSB consumption could be a potential risk factor for weight gain. By contrast, the same percentage of reviews in which a potential financial con-

13 [...] systematic reviews with financial conflicts of interest were five times more likely to present a conclusion of no positive association between SSB consumption and obesity than those without them. flict of interest was disclosed concluded that the scientific General Mills’ Bell Institute – which claims to be “com- evidence was insufficient to support a positive association mitted to supporting the work of health professionals by between SSB consumption and weight gain, or reported sponsoring educational efforts and developing not only contradictory results and did not state any definitive con- patient education materials but also continuing education clusion about the association between SSB consumption programs to advance the knowledge of health and foodser- and weight gain.” vice professionals” – has plenty of research on whole grains, but conveniently doesn’t address the fact that the company’s The authors found that “systematic reviews that reported whole grain offerings also contain added sugar and are pro- financial conflicts of interest or sponsorship from food or cessed to such a degree that they require enrichment and drink companies were more likely to reach a conclusion fortification. Whole grain is the first ingredient in General of no positive association between SSB consumption and Mills’ Cookie Crisp cereal, but that does not make it compa- weight gain than reviews that reported having no conflicts rable to a bowl of oatmeal. of interest.” More specifically, “systematic reviews with financial conflicts of interest were five times more likely to Coca-Cola’s Beverage Institute for Health & Wellness web- present a conclusion of no positive association between SSB site houses a page titled “Understanding Caloric Sweeteners consumption and obesity than those without them.” & Health.” In an attempt to deflect blame and make soda appear somehow wholesome (which the soft drink industry More importantly, “the interests of the food indus- desperately needs, since soda sales have been in freefall for try (increased sales of their products) are very different a decade), the website makes the following claims: from those of most researchers (the honest pursuit of knowledge).” Consequently, the authors write that “clear 1) “Studies show that under some circumstances, intake guidelines and principles (for example, sponsors should of sugars can boost performance on cognitive tasks.” sign contracts that state that they will not be involved in the interpretation of results) need to be established to avoid Although Coca-Cola is always quick to point out that sugar dangerous conflicts of interest.” is found all over the food supply (i.e.: “don’t blame soda for Americans’ sugar intake”), it presents its sugar-sweetened The spinning and reframing of existing science is just as beverages as the first option people should consider to boost problematic and pervasive as the funding of new research. performance on cognitive tasks. Never mind the fact that

14 sugars can also be obtained from whole fruit. Does Coca- recommended maximum intake of added sugars than the Cola expect health professionals to start recommending sips 25 percent figure it cites (the World Health Organization of soda for a brain boost? and the Scientific Report of the 2015 Dietary Guidelines Advisory Committee, for instance, recommend cap- 2) “The U.S. Institute of Medicine found that very high ping added sugar intake at 10 percent of total calories and very low intakes of added sugars were associated consumed). with lower micronutrient intakes. The report suggested an intake level of 25 percent or less of calories (energy) 3) “The causes of diabetes continue to be a mystery.” from added sugars in the total diet based on data showing decreased intake of some micronutrients in some While a multitude of factors can increase risk for the devel- population groups exceeding this level.” opment of Type 2 diabetes, a significant body of research has demonstrated that increased intake of sugar-sweetened This is misleading and irresponsible fear-mongering, which beverages is linked to a higher risk of developing certain attempts to argue that cutting back on added sugar could hin- chronic diseases, including Type 2 diabetes. der nutrition. What the Institute of Medicine actually says: More often than not, industry encroaches on science out of “Added sugars should comprise no more than 25 percent of a public relations-driven effort to engage in damage con- total calories consumed. Added sugars provide insignificant trol, particularly when consumption of, or consumer trust amounts of vitamins, minerals, or other essential nutrients. in, brands and products begins to dwindle. Considering Major sources include soft drinks, juice drinks, pastries, that the industry provides continuing education for vari- candies, and other sweets.” ous health professionals, including dietitians, its carefully constructed science narrative is troubling since it has the Coca-Cola’s claim conveniently ignores that plenty of potential to reach millions and be repeated by individuals scientific evidence supports setting a significantly lower who are seen as authority figures by patients and clients. ◆

Andy Bellatti, MS, RD, is a Las Vegas-based dietitian who approaches nutrition from a whole-foods, plant-centric framework. He also takes a strong interest in food politics, nutrition policy, and deceptive food industry marketing tactics.

15 Non-celiac gluten sensitivity: much ado about something? Small Amounts of Gluten in Subjects with Suspected Nonceliac Gluten Sensitivity: a Randomized, Double-Blind, Placebo- Controlled, Cross-Over Trial

16 Introduction Due to the lack of explicit diagnostic tools, much of the information on NCGS has been gathered from people who Few topics in recent years have polarized the nutrition and have self-reported to be gluten-sensitive. The purpose of health community as much as non-celiac gluten sensitiv- this double-blind, placebo-controlled, crossover trial from ity (NCGS). Some people believe it is a distinct condition, the University of Pavia in Italy was to study and classify while others simply do not believe it exists. NCGS has been symptoms in people suspected of having NCGS, when giv- observed for more than 30 years and refers to a subset of en small doses of gluten daily for one week. people (often self-diagnosed) who report problems when consuming gluten but don’t have any detectable autoimmune or allergic response in their bodies. Non-celiac gluten sensitivity (NCGS) is a controversial diagnosis of exclusion. It is only diagnosed when allergic NCGS is currently a diagnosis of exclusion. That means it and autoimmune issues are ruled out. The purpose of is diagnosed when an individual has had both allergic and this study was to describe the symptoms and characteris- autoimmune mechanisms ruled out, and the problems they tics of people suspected of having NCGS under blinded experienced when eating gluten-containing products go and controlled conditions. away on a gluten-free diet (GFD). This would ideally in a blinded fashion to avoid any placebo effect of the dietary intervention. One potential classification of the many possi- Who and what was studied? ble gluten-related disorders and symptomatology is shown The study recruited 61 adults who believed that they experi- in Figure 1. ence adverse reactions to gluten. The subjects were screened

Figure 1: Classifying gluten-related disorders

Source: Sapone et al., BMC Med. 2012 17 Celiac disease vs wheat allergy vs non-celiac gluten sensitivity

Allergic Reactions Autoimmune Immune mediated

Celiac disease (CD), dermatitis Pathogenesis Wheat allergy NCGS herpetiformis, gluten ataxia

Four of the following 5 for CD: 1. Typical symptoms of CD 2. Positivity of serum CD IgA class Excluding allergic and autoim- IgE antibodies - Skin prick autoantibodies at high titer Diagnosis mune reactions, improvement tests and in vitro IgE assays 3. HLA-DQ2 and/or HLA-DQ8 genotypes on a gluten-free diet 4. Celiac enteropathy found on small bowel biopsy 5. Response to a gluten-free diet

to be sure they did not have celiac disease or wheat aller- HLA genotyping and intraepithelial lymphocyte densi- gy. Potential subjects were also excluded for having lactose ty*). Subjects with NCGS were defined as those exhibiting intolerance, H. pylori infection, and intolerance to various a change in overall score between the placebo and gluten sugars, to prevent possible interference with the study results. weeks that was greater than two standard deviations away from the mean values. Subjects were given capsules containing either 4.375 grams of gluten a day (roughly the amount in two slices of white People suspected of having NCGS were randomized to bread) or rice starch (placebo) for one week, while other- receive either placebo or a dose of gluten roughly equivalent wise following a GFD. After a one-week washout period, to two slices of white bread daily for a week. After a week the participants crossed over into the other group, mean- washout period, participants who received placebo were ing they acted as their own controls, which is effective at given gluten for an additional week, and vice versa. Subjects eliminating inter-group differences. This study was dou- filled out questionnaires concerning symptoms to generate ble-blinded, as neither the researchers or the patients knew an overall symptom score, which was the main outcome who was in each group. By double-blinding the experiment, measure for this study. Various biochemical markers were the scientists ascertained that neither a potential bias on also measured to see if any could predict NCGS in patients part of the researchers, nor placebo effects on part of the who reacted strongly to gluten. subjects would affect the results. What were the findings? The intestinal and extra-intestinal symptoms, such as Among the 59 patients that completed the trial, gluten abdominal pain and bloating, brain fog, depression, and intake was associated with a 30% increase in overall symp- mouth sores, were assessed on a subjective basis via daily toms compared to the placebo. Two participants dropped questionnaires. The change in the weekly overall symp- out of the study due to intolerable abdominal pain during tom score (the sum of 15 intestinal and 13 extra-intestinal the first week of the study, but only one of them was receiv- symptoms) was the main outcome of the study. Secondary ing the gluten while the other was receiving the placebo. outcomes included the change in individual symptom scores that were used to identify subjects with NCGS, as In order to determine who could be labeled NCGS, the well as serum markers that could predict NCGS (includ- researchers analyzed each participant’s overall symptom ing serum IgG anti-gliadin antibodies, fecal calprotectin, scores (as the change in overall symptoms between the

18 Lab values that could gluten and placebo ingestion). Interestingly, over half of the sub- potentially predict NCGS jects (31, or 52%) experienced similar symptoms in the gluten and placebo condition. Only 9 subjects (15%) experienced sig- • Tissue transglutaminase IgA antibody- “Anti- nificantly greater numbers of symptoms in the gluten compared self” antibody, often abbreviated as “tTG”. with the placebo condition; and of those, only three subjects People with celiac disease make antibod- fulfilled the previously cited criteria for NCGS. ies that attack tissue transglutaminase, an enzyme that repairs damage in the body. The The researchers also analyzed the intestinal and extra-intestinal American Gastroenterological Association scores separately, with the results being comparable to the anal- recommends initial screening for celiac ysis for overall symptom scores. The main changes are shown in disease with tTG and confirmed by small Figure 2. When considering individual symptoms, 15 intestinal intestinal biopsy. symptoms were rated and significant worsening was observed • Serum IgG anti-gliadin antibodies (IgA and only for abdominal bloating and abdominal pain. Among the 13 IgG)- an “anti-gluten antibody,” as gliadin is extra-intestinal symptoms included on the questionnaire, foggy a component of gluten; IgA is made in the mind, depression, and aphthous stomatitis (mouth sores) were small intestine, which can be inflamed by the only ones that significantly worsened from gluten, compared gluten. IgG can also be used in diagnosing with placebo. However, a subject-specific analysis was not con- autoimmune problems, especially in people ducted so it’s not clear if the significance was driven exclusively by who are deficient in IgA (which is associated the low percentage of subjects who actually worsened on the diet. with celiac disease. Using these along with tTG may be more effective for celiac screen- Figure 2: The main symptoms of non- ing than tTG alone. celiac gluten sensitivity found • Fecal calprotectin - Stool test which can detect inflammation in the intestines • HLA genotyping - This test can rule out celiac disease and the genetic susceptibility for it. Approximately 97% of celiac patients have the HLA DQ2 or DQ8 genotype. • Intraepithelial lymphocyte density - an increase can imply a state of T cell activation, either antigen driven (possibly by gluten). Sensitivity (ability to identify those with the dis- Additionally, the researchers attempted to identify lab mark- ease) and specificity (ability to identify those ers for NCGS, though no significant correlations were found without the disease) of the markers is varied... between either IgG anti-gliadin antibodies (IgG AGA), intraep- (From Benson et al) ithelial lymphocytes, or HLA-DQ2/DQ8 gene status and the changes in overall symptoms score. However, two of the three participants deemed to have NCGS did have IgG AGA levels tTG IgA AGA IgA AGA IgG above the normal range. Reported 90-98% 80-90% 75-85% Sensitivity

Reported 95-97% 85-95% 75-90% Specificity

19 correlations between NCGS and other potential markers, Gluten consumption increased overall symptom scores this study could not find biomarkers that could be predic- by 30% compared to placebo, with abdominal bloating tive of NCGS or shed light on any underlying mechanisms. and pain, foggy mind, depression, and mouth sores being The authors report that further experiments are currently the worst symptoms. Over half the subjects had similar being undertaken to classify the cytokine response in the symptom scores when taking gluten or placebo. Most bio- intestines of subjects enrolled in the current study, and that markers showed no correlation to symptom development, early data does not support a role for either the innate or although the IgG AGA antibody was above normal range adaptive immune response. in two of the three participants determined to have NCGS. Because a reliable diagnostic tool for NCGS does not currently exist, and the fact that placebo (and nocebo) effects What does the study really can be very strong, blind challenges are necessary to diagnose this condition. To ensure valid results during this trial, tell us? the authors pre-tested the gluten capsules to make sure In a nutshell, the severity of overall symptoms increased they had the same taste and appearance as the placebo, and with one week of gluten intake compared with one week potential participants exhibiting only minor symptoms were of placebo. What is more important, however, is that even excluded. Patient compliance to the supplement regimen though the overall mean symptom score was significantly and the gluten-free baseline diet was good, and was mon- higher for the gluten group in comparison to the placebo itored throughout the trial. The one-week washout period group, the result was driven by changes in only a subset of may seem short, but the fact that the scientists were able to participants. The results suggest that there may have been a detect significant effects suggests that this was a sufficient nocebo effect in some patients, meaning the mere expecta- amount of time. tion of potential increases in symptoms triggered a negative

effect. Put another way, most of the people who thought The amount of gluten used in this study was lower than in they were gluten sensitive were not (or at least it wasn’t some previous trials but certainly a normal physiologic dose measurable under these experimental conditions). (one sandwich per day). It cannot be excluded, though, that higher doses could possibly cause other problems related to With only two out of three identified NCGS patients having fermentation in the gut, even in healthy people. Analyzing IgG levels above the normal range and a lack of significant The results suggest that there may have been a nocebo effect in some patients, meaning the mere expectation of potential increases in symptoms triggered a negative effect.

20 overall symptom changes as well as individual symptoms allowed for a robust study on any potential effects of gluten, however the fact that there is no similar analysis of the The fact that, intra-individual differences for the individual symptoms (there’s only group data) is a weakness that can generate the for most subjects, impression that everyone got brain fog, etc.

The fact that, for most subjects, the symptoms worsened to the symptoms the same extent during the gluten and placebo treatments highlights the importance of nocebo effects in studies worsened to the on NCGS. Confirmation of NCGS should be interpreted carefully due to the lack of a control group that did not same extent during believe gluten was the cause of problems in their bodies. In addition, future studies should consider a potential the gluten and dose-dependence of the effects. With the equivalent of only one sandwich per day, the gluten load may have been too placebo treatments low to elicit significant differences between the two treatment conditions. It is possible that higher gluten doses highlights the could have resulted in a larger group of sensitive patients. importance of There may be a strong nocebo effect for people claiming to have NCGS, at least at low doses of gluten. This nocebo effects in suggests that in real-world practice, blind challenges to gluten would be useful to diagnose NCGS. studies on NCGS.

The big picture not in as many people as is sometimes suggested. As is so This study contributes to the growing body of NCGS often the case, more research is needed. research. A recent review found prevalence rates between 0.5-13%, with this large discrepancy partly due to stud- Frequently Asked Questions ies using a range of populations and partly due to varying I heard NCGS was actually a problem with FODMAP foods? inclusion/exclusion criteria. In addition, quantifying the FODMAPs (Fermentable Oligo-, Di-, Mono-saccharides prevalence of NCGS is challenging in the absence of specific And Polyols) refer to some types of carbohydrates that are biomarkers for diagnosis. found in foods. These are found in some types of fruits, dairy, legumes, garlic, onion, and wheat. An often cited Considering that a family history of celiac disease is prev- study from 2013 suggested that a FODMAP intolerance, alent among NCGS patients, it is possible that people not gluten itself, was the problem for people. What the classified as NCGS are actually celiac. Additionally, in view media usually failed to report was that the participants in of the altered gut permeability in IBS patients after gluten that study all had IBS, a pathology that has been shown to exposures, it is also possible that NCGS could be a subset of respond favorably to a low FODMAP diet. Furthermore, the IBS. It appears that NCGS does in fact exist, but potentially

21 scientists excluded participants if they had intra-epithelial where the more gluten they eat, the worse they feel. Others inflammation in the duodenal mucosa (Marsh 1 lesion), may feel somewhat bad after eating bread, but even worse which is common in IBS subjects who have responded well after eating gluten-containing products that may have oth- to a GFD. Therefore, while FODMAP intolerance may be a er components that cause a reaction. Gut disorders (and cause of symptoms after eating wheat, it doesn’t necessarily the huge variety of other health disorders that can appear explain all cases of non-celiac sensitivity to wheat. alongside them) make it difficult to self-diagnose, and thus getting help from a healthcare provider is often essential. Is it possible that something else in wheat, besides gluten, could be the issue? What I should know? Non-celiac wheat sensitivity may in fact be a more appro- This study adds more weight to the evidence that gluten may priate label than NCGS, as gluten per se may not be the cause problems that cannot be ascribed to either an allergic only problematic component of wheat. A 2013 review titled or autoimmune reaction. Furthermore the possible extent “Non-celiac gluten sensitivity. Is it the gluten or the grain?” of nocebo effects observed in the study at hand suggest concluded that while there is clearly a connection in some that many people who consume a GFD may be doing so patients between grain ingestion and symptoms in the unnecessarily. A direct tool for diagnosing NCGS has yet to absence of celiac disease or wheat allergy, whether NCGS be determined, and reports of population-wide prevalence is more closely related to the spectrum of celiac disease or remain widely variable. ◆ inflammatory bowel disorders warrants further study.

Further confounding self-diagnosis is the fact that the Are the gluten wars winding down, or just beginning? usual suspects aren’t the only suspects when it comes to Discuss the contentious issue of NCGS at our private causing “gluten” reactions. Figure 3 shows some less obvi- Facebook forum. ous sources of gluten as well as a few of the many gluten alternative grains. Some people have fairly simple patterns

Figure 3: Some common foods that contain gluten

22 Baby probiotics for prevention of ADHD and Asperger’s A possible link between early probiotic intervention and the risk of neuropsychiatric disorders later in childhood: a randomized trial

Introduction Diagnoses of developmental disabilities in children are on the rise in the United States, with increases in attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders such as Asperger’s syndrome (AS) leading the trend. Knowing how to stem this tide would be useful. But how?

One tantalizing possibility may be probiotics. Research into the “gut-brain axis” is a hot topic right now, one we’ve most recently explored in ERD #6 in the article “Can fiber change your emotions?” While the research is still young, mounting animal and human evidence suggests that the gut microbiome can affect brain activity. Since developmental disorders such as ADHD and AS involve the brain, perhaps probiotic supplementation may affect these disorders as well. This idea is bolstered by the fact that many children on the autistic spectrum have concurrent gastrointestinal issues and abnormal gut bacteria. Furthermore, one hypothesis for how ADHD develops, at least in some cases, has to do with immunologic hypersensitivity to environmental triggers. And some of the authors of the study under review found that probiotics are able to mitigate some aspects of this type of hypersensitivity in children.

23 The sum of these ideas suggest that probiotics in early life could influence the development of ADHD and AS later in life. This study intended to put this theory to the test. Are ADHD and AS connected? Mounting evidence suggests that gut bacteria may ADHD involves inattention, impulsivity, and hyper- influence brain activity. This presents the possibility activity, whereas AS is characterized by stereotyped that probiotic supplementation could also influence behavior and impaired social and communication childhood developmental disorders such as ADHD and skills. There seems to be little in common between Asperger’s syndrome. these two disorders at first glance, so why did the authors of this study decide to examine the effect of probiotics on these two seemingly disparate Who and what was studied? conditions? The purpose of this study was to determine whether probiotic supplementation during infancy affected the One feature of ADHD is that it’s rarely seen on its development of either ADHD or AS by age 13. However, own. In the words of two researchers: “It is the this study is actually a repurposed follow-up of a previous exception, not the rule, to encounter cases with study that looked at whether probiotic supplementation ‘pure’ ADHD.” The same also seems to hold true for could prevent allergic hypersensitivity in infants. Because AS; attention issues and full-blown ADHD can be of this, the infants recruited for the study all had at least found in children with AS as well. The reason why one relative with an allergic disease in order to increase the aspects of these conditions may overlap may come chances that the infants would also have an allergic disease. down to where they occur in the brain. Both involve some of the same regions of the brain, in what is In the original study, 159 mothers were randomized to known as the frontostriatal system. Disorders that receive either 10 billion colony-forming units daily of arise from this region are thus known as frontostri- Lactobacillus rhamnosus GG (LrGG) in capsule form or atal disorders, which include ADHD and AS. Recent placebo four weeks before the infants were born. This com- neuropsychological evidence suggests that ADHD monly studied probiotic is described in Figure 1. After birth, and AS share some similar brain circuits and both the mothers continued taking the dose if they breastfed involve problems with managing cognitive pro- their infants. If the infants were not breastfed, they were cesses and emotions, self-control, and executing given the contents of the capsule mixed with water. Most complex tasks (collectively known as executive dys- mothers gave the capsules directly to their infants, but some function), implying that both disorders may have infants never received the capsules. Instead, the breastfeed- some underlying similarities. ing mothers took the capsules for the duration of the study. The dosing of the mothers or infants continued for six So while it seems a bit strange to think that a single months after birth. intervention could affect the development of two seemingly different disorders such as ADHD and AS, Stool samples were taken from the infants multiple times, there are some good reasons to put them in one from three weeks of age to 24 months. These samples were basket for the purposes of this study. used to measure the composition of the infants’ gut microbiome using two different methods: fluorescein in situ hybridization, which uses fluorescent DNA probes that bind

24 Figure 1: The illustrious Lactobacillus rhamnosus GG

to known sequences of DNA (in this case, specific to microbial species) to identify and count them, and quantitative Children (or their mothers if and when the child was PCR, which amplifies known segments of the DNA of dif- breastfed) were randomized to Lactobacillus rhamnosus ferent microbial species to detect and count them. GG supplementation or placebo for up to six months of age. The infants’ gut microbiome was analyzed. After the In this study, the investigators followed up with the children children reached 13 years of age, their gut microbiome when they were 13 years old to see if LrGG dosing affect- composition was again analyzed. The authors examined ed the development of either ADHD or AS. A fecal sample whether or not supplementation in early life affected was taken again to analyze the gut microbiome. The chil- diagnosis with ADHD or Asperger syndrome later on. dren were diagnosed with ADHD or AS using criteria from the International Classification of Diseases (ICD-10) by an experienced psychologist, who was blinded to the treatment What were the findings? groups. In the United States, the Diagnostic and Statistical Out of the 159 people who participated in the original study, Manual of Mental Disorders (DSM) is more often used for only 75 people participated in the 13-year follow-up. The diagnosis of these conditions. AS was removed from the DSM participation rate was roughly equal between both groups: in 2012 and incorporated into “autism spectrum disorder”. 40 children (53.3%) of those who received LrGG and 35 Possibly because the current study was conducted outside of (46.7%) who received placebo participated. The two groups the US, ICD was used instead of DSM for diagnosis. had similar characteristics. Those who dropped out for the 13-year follow-up also had similar characteristics to those who remained in the study, except for one notable difference:

25 Why did the the dropouts had significantly fewer exclusively breast-fed months than partici- researchers use pants who remained in the study (three months for those who remained in the Lactobacillus study, two months for the dropouts). rhamnosus GG? In terms of psychiatric conditions, three children were diagnosed with ADHD, one child was diagnosed with AS, and two children had both ADHD and AS Out of all of the different bacte- by age 13. All of the diagnosed children were in the placebo group, and all were ria they could have chosen, why male. There were no ADHD or AS diagnoses in the LrGG-treated group. These would the authors choose to use differences in ADHD and AS incidence between the LrGG-treated group and LrGG as a probiotic supplement? the placebo group were statistically significant.

The study under review is a fol- There were significantly fewer cases of ADHD and AS in the LrGG-treated low-up to a previous study group, but did LrGG treatment affect the gut microbiome compared to pla- whose goal was to examine the cebo? The short answer is “yes” in early life, but with little rhyme or reason. prevention of allergic hypersensi- Specifically, at three months of age, Bifidobacterium longum was underrepre- tivity in infants. The main reason sented in the Bifidobacterium genus in participants who went on to develop the authors used LrGG in the origi- ADHD or AS by age 13, and Bifidobacterium as a whole was deficient in nal study was that they previously that population at six months. At 18 months, Bacteroides and Lactobacillus- found that this strain reversed food Enterococcus group bacteria were lower in those who ultimately developed allergy-induced gut permeability neuropsychiatric disorders (recall that the supplemented bacterium was from in rats, and also modulated the the genus Lactobacillus). At 24 months of age, those who went on to develop immune response in a way that ADHD or AS tended to have lower counts of Clostridium histolyticum. Finally, reduced allergic reactions. at age 13, there were no significant differences seen in the gut microbiome between children with ADHD and AS, compared to children without these The reason why the authors chose disorders. There’s a chance that these seemingly random differences in the gut this bacterium had little to do microbiome through time may actually be random though, since the authors with the gut-brain axis, and more made many comparisons and didn’t seem to correct for them. to do with the bug’s ability to modulate allergic responses. As While supplementation with LrGG early in life was linked to lower incidence of luck would have it, however, lat- ADHD and AS by age 13, there was no consistent difference in the gut microbi- er animal studies suggested that ome between those who developed the disorders and those who didn’t. L. rhamnosus supplementation could affect brain functioning as Supplementation with Lactobacillus rhamnosus GG during the first six well. Perhaps studies like these months of life was associated with a lower risk of developing ADHD or are what inspired the authors to Asperger’s by age 13. Although there was no difference in the gut microbi- follow up on their original allergy ome between children who had the disorders and those who didn’t at age 13, study and test for psychological there were some minor, inconsistent differences early in life. effects over a decade after their original allergy study ended.

Science is full of interesting What does the study really tell us? accidents. The authors describe this study as being a “preliminary and initial observation.”

26 This should be emphasized, as there are quite a few limitations to this Figure2:- Why loss to study. follow-up is so important

One of the main limitations is “loss to follow-up.” Recall that this study is actually a follow-up to a previous study. That initial study was not designed to see whether probiotics prevent ADHD and AS after 13 years, but instead to see whether six months of supplementation could prevent allergic hypersensitivity after two years. During the gap between the original study and this follow-up, around half of the subjects from the original study were lost. This phenomenon of “loss to follow-up” presents a large problem in interpreting the results, since we don’t have any idea whether or not these patients developed ADHD or AS. And if some of them did, especially in the placebo group, this could dramatically affect the results, as shown in Figure 2 One rule of thumb suggests that having a loss to follow-up of more than 20% is a serious problem. In this study, the loss was about 50%.

There is also some evidence to suggest that the unobserved placebo group may have a higher risk of neuropsychiatric issues. Recall that the children who participated in the 13-year follow-up had significantly more months of exclusive breastfeeding than those who were lost to follow-up. Some observational evidence suggests that breastfeeding may have a protective effect against ADHD and childhood conduct disorders. So while there were few differences in the measured variables between those children which participated in this 13-year follow-up and those who didn’t, the difference in the length of exclusive breastfeeding between those who were included in this study and those who were not may be enough to introduce serious confounding.

The difference in breastfeeding early in life between those who participated in the 13-year follow-up and those who didn’t may have also confounded the findings concerning the gut microbiome. Breastfeeding is known to affect the gut microbiome, increasing the amount of bifido- bacteria in the gut. Since breastfeeding affects the composition of the gut microbiome, and there was a difference between those included in the study and those who were lost to follow-up, the microbiome data presented in the study may be confounded as well.

It should also be noted that there was a statistically non-significant difference in the length of exclusively breastfed months in the children who were analyzed at age 13: those children who went on to develop ADHD

27 Figure 3: Environmental and epigenetic determinants of ADHD

or AS were breastfed exclusively for two months on average, The big picture compared to three months on average for the healthy chil- Both ADHD and the autism spectrum disorders such as AS dren. Because of the smaller sample size in the follow-up have strong genetic components. However, environmental population, this difference was not statistically significant (p factors could influence the development of these disorders. = 0.16). However, given that breastfeeding may impact both The “nature versus nurture” aspect of ADHD specifically is the microbiome and the risk of behavioral disorders later depicted in Figure 3. in life, it would have been interesting to see whether LrGG supplementation would have still have a significant impact Environmental effects associated with an increased risk of on ADHD/AS development if length of breastfeeding was ADHD include maternal smoking, premature birth, and taken into account. Unfortunately, the authors did not pro- exposure to environmental toxins such as lead and poly- vide this analysis. chlorinated biphenyls (PCBs). Diet has also been examined in the context of mitigating existing symptoms, although Finally, it’s important to keep in mind that this study was with mixed results, in part due to low study quality. There actually a follow-up of previous study that was designed to is little evidence concerning the role of dietary supplemen- look at probiotics’ effects on allergic hypersensitivity. The tation in reducing the risk of developing ADHD or AS in original study was not designed to look at ADHD and AS. the first place though, which is partly what makes this study For this reason, the results of this study, while useful to novel and interesting. guide further research, should be considered preliminary.

The idea that omega-3 fatty acids may influence the devel- The results of this study should be taken with a grain of opment of both ADHD and the autism spectrum disorders salt due to a large loss of participants over time and pos- has recently been gaining traction, though. One omega-3 sible confounding issues. fatty acid, docosahexaenoic acid (DHA), accumulates in the fetal brain throughout gestation and continues to build

28 during the first two years of life, suggesting that early supplementation may be useful. Furthermore, higher levels of Both ADHD serum DHA, which is present in breast milk, is correlated with higher childhood cognitive function and decreased hyperactivity and impulsivity. Preliminary evidence also and the autism suggests that DHA levels inversely correlate with the risk of autism. These facts may partially account for the increased spectrum risk of ADHD in premature birth mentioned above, as well as the possible protective role of breastfeeding as mentioned disorders such in the last section. Indeed, a recent case control study has found that omega-3 fatty acid deficiency may be a risk fac- as AS have tor for both ADHD and autism spectrum disorders. strong genetic While the research is still young, studies like this one provide interesting hypotheses concerning the role of supplementation in the prevention or amelioration of developmental components. disorders, which can be tested through additional studies. However, While genetics seems to play a significant role in the environmental development ADHD and Asperger syndrome, recent preliminary evidence suggests that dietary supplementation factors could could hypothetically impact the risk of developing these disorders. More rigorous studies are needed to confirm these ideas. influence the development of Frequently asked questions Isn’t it weird that the researchers supplemented breast- these disorders. feeding mothers? How could that influence their child’s gut microbiome? forming units of LrGG per gram, as opposed to 4.0 × 107 It is a little weird. The rationale the authors gave in the orig- in those infants who directly took the supplement, which is inal study for this protocol was that giving the probiotics to a 40,000-fold difference. So, this doesn’t shed a whole lot of infants directly or to their nursing mothers “have resulted light on the matter. Furthermore, no explanation of why the in similar amounts of Lactobacillus GG in infant faeces.” counts would be similar or the mechanism by which supple- However, the citation they provide to back up this statement menting nursing mothers with LrGG could directly affect doesn’t clearly support this, as only ranges were given with LrGG counts in their breastfed infants could be found. no statistics like standard deviation or means, and no statistical tests which show that the difference between groups However, a recent clinical study has shown that supple- was not statistically significant. Furthermore, the lower end menting breastfeeding mothers both before and three of the range of fecal counts in breastfed infants whose moth- months after birth with a probiotic mixture did increase the ers received the supplement for a month was only 103 colony

29 levels of LrGG found in the infants early in life compared All of the children included in this study were at risk for to mothers who were administered a placebo. Whatever allergies. Could this have affected the risk of these children the mechanism, it seems like probiotic supplementation of developing ADHD or AS at all? breastfeeding mothers may influence some aspects of their Maybe. Bronchial asthma and allergic rhinitis may be asso- child’s microbiome. ciated with an increased risk of ADHD, leading some to hypothesize that ADHD could be in part due to hypersensi- All of the children who developed AS and ADHD in this tivity to environmental triggers. In addition, food allergies study were male. Are males more at risk for these disorders? may be more prevalent in children with autism spectrum Yes. Both disorders are more prevalent in males. Males are disorders. So it’s possible that this population of children roughly four times more likely to develop autism spectrum may have had an increased risk of developing ADHD or AS, disorders. In fact, all four initial cases described by Hans although more research needs to be done on this topic. Asperger were males. Roughly three times as many males get ADHD than females. What should I know? This randomized, placebo-controlled study found that sup- The original study from these authors was about the effects plementation with Lactobacillus rhamnosus GG in the first of probiotic supplementation on allergic hypersensitivity. six months of life attenuated the development of ADHD or Were the results of that original study promising? Asperger syndrome by age 13. However, these results should Yes. The risk of atopic eczema, the main allergic outcome, be considered preliminary due to large loss to follow-up was halved with probiotic supplementation. Furthermore, and the presence of confounding. Further trials, which lack the risk was mitigated in both infants whose mothers took these limitations, are needed to confirm the results.◆ LrGG while breastfeeding, as well as for those infants who were directly administered the probiotic. Supplement your knowledge about this article and others over at the ERD private Facebook forum!

Males are roughly four times more likely to develop autism spectrum disorders. In fact, all four initial cases described by Hans Asperger were males. Roughly three times as many males get ADHD than females.

30 Putting the “D” in Death A reverse J-shaped association between serum 25- hydroxyvitamin D and cardiovascular disease mortality – the CopD-study

Introduction IU to 600 IU daily for all people ages 1-70 years old, as a response to the vastly larger base of higher-quality studies The recommended daily allowances for vitamins and miner- published since 1997, when the recommendation was first als were first established by the Institute of Medicine (IOM) established. Yet, this updated recommendation continues to in 1943. Since then, small revisions have been made peri- come under fire from researchers across the world. odically to incorporate new scientific knowledge. Perhaps the largest change came in the 1990s, when new findings Recent evidence suggests vitamin D is implicated in numer- linking diet, health, and chronic disease challenged the ous chronic diseases and adverse health conditions outside status quo. In response, the IOM embarked on an initiative of its primary role in skeletal health. However, the optimal to develop a new, broader set of dietary reference values, blood level of vitamin D [measured as 25(OH)D] is a matter known as the Dietary Reference Intakes (DRIs). of considerable debate. Vitamin D deficiency and insuf- ficiency have been defined by the Endocrine Society as a Since the publication of the DRIs between 1997 and 2005, 25-hydroxyvitamin D [25(OH)D] <20 ng/mL and 21-29 ng/ the only vitamin to be revisited is vitamin D. In their 2010 mL respectively, with optimal levels for health considered to report, the IOM tripled their recommendation from 200 be 30-40 ng/mL.

31 Of great concern, however, is the notion put out by the IOM tion with 25(OH)D levels of 40-49 ng/mL. Importantly, that the mortality curve for blood levels of 25(OH)D is there was no increased risk of death with increased 25(OH) U-shaped, indicating an increased risk of death associated D concentrations. with both too low and too high 25(OH)D levels . This was supported by research showing 25(OH)D blood levels of 20-25 This matters because an estimated one billion people world- ng/mL are associated with the lowest mortality risk in a cohort wide are vitamin D deficient or insufficient, and analysis of nearly 250,000 Denmark citizens. However, two recent sys- of the NHANES 2005-2006 data suggests that 41.6% of tematic reviews and meta-analyses challenge this view. Americans are deficient. Yet, death from any cause is a broad umbrella under which some health outcomes may The first, published in April 2014, was a systematic review hold more weight than others, and thus unfairly influence and meta-analysis of 73 observational and 22 randomized the relationship between 25(OH)D and mortality. This is controlled trials (RCTs) with 849,412 and 30,716 partici- why researchers look into more specific relationships, such pants, respectively. as that between Analysis of the vitamin D and the observational stud- number one global ies showed that [...] an estimated one killer – cardiovascu- the risk of death lar disease (CVD). from any cause billion people worldwide was increased by Unfortunately, the 16% for each 10 are vitamin D deficient or results are not clear- ng/mL reduction cut. According to the of 25(OH)D lev- insufficient study under review, el below 30 ng/ there have been no mL, while analysis of the RCTs revealed that vitamin D3 less than 24 published studies estimating the association supplementation (10-6000 IU/day) compared to placebo or between 25(OH)D levels and CVD mortality. Some of the no treatment reduced the risk of death by 11%. To put this studies did find an association between low 25(OH)D levels into perspective, using the population prevalence estimates and increased CVD mortality, but others did not, and some of vitamin D deficiency from this study, 9.4% of all deaths even found an inverse association only among those with in Europe and 12.8% of those in the United States could be low 25(OH)D levels. These discrepancies may be due to attributed to vitamin D deficiency. different study populations and follow-up procedures. Thus, the current study sought to evaluate the association between The second, published in August 2014, reviewed 32 obser- CVD and 25(OH)D concentrations of a Denmark-based vational studies from 1966 to 2013 with more than 500,000 cohort of 243,672 men and women. participants. In 25 of the 32 studies, there was a significant association between reduced all-cause mortality and high- Serum 25(OH)D concentrations appear to be protective er 25(OH)D concentrations, which was confirmed by the against death from any cause when between 30-40 ng/mL, meta-analysis showing that, in general, blood 25(OH)D lev- with no apparent risk as concentrations increase further. els ≤30 ng/mL were associated with a significantly increased However, data specifically looking at cardiovascular dis- risk of death compared to ≥30 ng/mL. Specifically, the point ease is conflicting. at which the risk of death stopped declining significantly was 36 ng/mL, although there was a trend for further reduc-

32 Who and what was studied? To help visualize the characteristics of the study population, the researchers split them into seven categories of serum The current study relies on data obtained from the 25(OH)D levels. The lowest and highest categories were ≤5 Copenhagen General Practitioners Laboratory, which is ng/mL and ≥50 ng/mL, respectively. The lowest incidence of the sole blood test center for physicians within the greater CVD mortality was observed at concentrations of 20-30 ng/ Copenhagen area in Denmark. Overall, 243,672 men and mL, with mortality increasing as 25(OH)D levels fell below women had their 25(OH)D levels tested. This data was and rose above this range. However, graphing of these accessed to conduct the analysis. Additionally, every citi- outcomes revealed a reverse J-shape curve, indicating that zen in Denmark has a personal identification number that mortality was more prevalent in people with lower 25(OH) enables matching of individuals to a civil registration data- D concentrations. In support of this pattern, 78.1% of all base, thus providing the researchers with a 100% follow-up CVD mortalities were in people with 25(OH)D levels below rate and allowing them to discern cause of death in the 30 ng/mL. The separated results for stroke and myocardial vitamin D cohort. infarction are shown in Figure 1.

What were the findings? Of note, the chance of men dying from CVD was signifi- The median follow-up duration of the participants was about cantly greater than the chance of women dying only when three years, which is not a long time when looking at chron- 25(OH)D levels were below 30 ng/mL. Moreover, similar ic diseases, such as CVD, that may take decades to become results were found when the researchers looked at two CVD noticeable. Nonetheless, fatal CVD accounted for 5,474 of sub-categories – stroke and heart attacks, with the excep- the 16,645 registered deaths, or about nine people per every tion that in women the lowest heart attack mortality was 400. Death was more common during winter months. seen with 25(OH)D levels of 16 ng/mL rather than the 30

Figure 1: Mortality curves differ between men and women

33 ng/mL seen with men and with both sexes for stroke and Figure 2: Some of the total CVD mortalities. possible causal paths

About 2.25% of deaths in the Denmark-based cohort were from CVD. The lowest incidence was observed in people with 25(OH)D levels of around 30 ng/mL. The number of deaths increased as blood levels rose above and fell below this amount, forming a reverse J-shaped curve on a graph. Mortality was far more prevalent in people with 25(OH)D levels below 30 ng/mL compared to the above.

What does this really tell us? The inherent limitations present in observational studies apply to the conclusions of this study. For instance, the entire cohort was from the greater Copenhagen area in Denmark, which not only limits the generalizability of these results to that geographical location but also to the Danish lifestyle. Previous analysis of Danish citizens using data from the Danish National Health Survey 2010 has found that 72.9% reported active commuting each day and that 50.6% met the recommended levels of physical activity (150 min/week moderate-intensity physical activity [MVPA]) from active commuting alone. If we compare this to the 65.3% of U.S. citizens that average less than ten minutes/day of MVPA, it is obvious why extending the CVD mortality associations to other populations, like Americans, would be a long shot.

Additionally, the correlational nature of the study also presents a barrier to forming any satisfactory conclusions from the results. Observational evidence, the kind presented in the current study, cannot establish causality, as shown in Figure 2. While it sounds good to say that too low or too high 25(OH)D levels may increase the risk of dying from CVD, it would be equally accurate to conclude that other risk factors for CVD lead to reduced or elevated 25(OH)D levels. As an example, obesity and sedentariness all greatly increase the risk of CVD while simultaneously reducing 25(OH)D levels due to sequestration into excess fat tissue

34 and reduced time spent outdoors in sunlight. The lack of information on other important risk factors, such as BMI, Though large, this study is still observational, making body composition, physical activity, ethnicity, and smoking causal conclusions difficult to draw. Danes also have is a significant limitation to the study under review. unique characteristics, which make generalizations to other populations questionable. Another important limitation is that this study relied sole- ly on 25(OH)D measurements taken at one point in time, which may not capture lifestyle or other changes that may The big picture alter 25(OH)D levels and/or the risk for CVD. Nonetheless, Observational evidence the researchers did control for seasonal variations in the The current study adds one more observational cohort to analysis, and previous research in a large Norwegian cohort the already large base of conflicting results. Rather than suggests 25(OH)D levels to be relatively stable over the sorting through every published study outcome, it is more long-term. efficient to look at research that synthesizes the conflict into consensus. An early meta-analysis of Caucasian pop- With these limitations in mind, the current study does ulations from Europe and the USA found the risk of CVD have two major strengths. First, the sample size was huge to increase as 25(OH)D levels fell below 24 ng/mL, with for being a no appar- single cohort, ent change and second, It appears that the in risk with the range of levels above 25(OH)D mea- 24 ng/mL. surements was majority of observational A separate broad, with meta-analy- thousands of research supports the notion sis looking at people below death from 5 ng/mL and that low 25(OH)D levels are vascular above 50 ng/ causes found mL. Most associated with CVD. similar results, research uses with the arbitrary cut- incidence of off points that place the upper limit around 30-40 ng/mL, vascular-related death to be about 21% higher in people preventing us from seeing how higher levels, especially in with 25(OH)D concentrations below 18 ng/mL, when com- the extremes, may associate with CVD risk. pared to those with levels above 26 ng/mL.

Nonetheless, the only conclusion that can be soundly made The above outcomes were recently confirmed by researchers is one constrained by many caveats: the current study shows from the German Cancer Research Center, who conduct- a reverse J-shaped association between CVD mortality and ed a meta-analysis investigating the relationship of serum serum 25(OH)D levels in a large Danish cohort, with the 25(OH)D levels and cause-specific mortalities in eight pro- lowest mortality rate seen around 30 ng/mL in both men spective cohort studies from Europe and the USA with over and women, and the greatest mortality rate observed in 26,000 men and women. After controlling for important people with lower levels. confounding variables, there was a significant but modest

35 The current study doesn’t tell us if supplementation actually helps. And unfortunately, RCTs show mixed results. rise in CVD mortality risk as 25(OH)D concentrations fell stimulating blood vessel constriction and sodium and water below ~24 ng/mL. retention. Inappropriate stimulation of this system, especially chronic stimulation, is suggested to play a pathological It appears that the majority of observational research sup- role in CVD through hypertrophy and remodeling of heart ports the notion that low 25(OH)D levels are associated cells, heart attacks, hypertension, and atherosclerosis. with CVD. This is consistent with the Endocrine Society’s Clinical Practice Guideline for the evaluation, treatment, There is also some evidence that vitamin D modulates and prevention of vitamin D deficiency, which claims opti- glucose tolerance through pancreatic β-cell function and mal 25(OH)D levels to be between 30 and 40 ng/mL and insulin sensitivity. Vitamin D receptors are present in anything less to be insufficient. pancreatic β-cells, and mice lacking functional vitamin D receptors show impaired insulin secretion. Similarly, it has Mechanistic evidence been shown that vitamin D deficiency in rats impairs glu- Nonetheless, the relationship between low vitamin D status cose-mediated insulin secretion, and that supplementation and CVD warrants a discussion of the possible mechanisms. with vitamin D restores this function. Vitamin D stimulates Experimental research provides several avenues through the expression of insulin receptors and enhances insulin which this association can be at least partly explained, responsiveness for glucose transport in vitro. A dysregula- including vascular health, blood pressure and glucose regulation of glucose tolerance is the hallmark of diabetes, a strong tion, and inflammation. Vitamin D receptors exist on nearly risk factor for the development of cardiovascular diseases. every cell type, including those that form our blood vessels. It has been shown that normal concentrations of vitamin D Finally, vitamin D may also influence CVD indirectly. In have a relaxing effect on vascular muscles, reduce clot forma- 2013, researchers from the Netherlands conducted a system- tion and increase their breakdown, and reduce inflammation, atic review of all meta-analyses since 1988 that investigated all of which act to prevent plaque formation in the blood blood-borne biomarkers for CVD. In total, 61 meta-analy- vessels. Conversely, vitamin D levels that are too low inten- ses were found for populations without pre-existing CVD. sify the activity of enzymes involved in vascular remodeling, The strongest risk factor identified was C-reactive protein which leads to stiff and less compliant blood vessels. (CRP), a common biomarker of systemic inflammation, and a recent meta-analysis of ten trials involving a total of 924 In addition to direct effects on the blood vessels, vitamin D participants showed that vitamin D supplementation sig- may interact with regulators of blood pressure. Specifically, nificantly decreased the level of circulating CRP. research in mice has shown that a lack of vitamin D leads to an increase in the expression of renin, which is the first and Weaknesses of studies rate-limiting component of the renin-angiotensin system The current study doesn’t tell us if supplementation actu- that acts to increase blood volume and pressure through ally helps. And unfortunately, RCTs show mixed results.

36 Moreover, CVD is a chronic disease that takes years, if not decades, to develop and comes about as a result of numerous risk factors. Trials assessing vitamin D supplementation may only examine a handful of secondary endpoints, such Many studies as cholesterol levels, and attempt to build a puzzle with only some of the pieces, which doesn’t work so well. have fallen Perhaps the biggest problem is the study design. It is not uncommon to see RCTs published that report null, or even into the trap of adverse effects of supplementation interventions without giving consideration to the baseline nutrient status of the study working at either participants. Yet, the effects of nutrient intake follow a somewhat S-shaped curve. At the extreme left of deficiency there the low- or the is little change in the desired outcome until some threshold is met, at which point the effect increases with increasing high-end of this nutrient intake until the relationship again forms a flat line, where no further benefits are observed. The outcomes of RCTs thus depend on the starting point of the study subjects nutrient response and the magnitude of change in nutrient status. curve, using Many studies have fallen into the trap of working at either the low- or the high-end of this nutrient response curve, nutrient doses using nutrient doses that are too low to measure an effect or using adequate doses in individuals who were already suffi- that are too low cient in that nutrient. Meta-analyses are not free from fault either, as averaging results across an intervention group will to measure an often blur, if not totally obscure, an underlying real effect. effect or using To overcome these deficits, a set of guidelines for optimizing design and analysis of clinical studies of nutrient effects has recently been published. Five rules were suggested for RCTs, adequate doses which for vitamin D would translate to studies that enrolled populations with a deficient 25(OH)D level (≤20 ng/mL) in individuals and then supplemented them with enough vitamin D per day to raise their 25(OH)D levels to 30-40 ng/mL. who were already

If we use these criteria when analyzing research looking sufficient in that into the effects of vitamin D supplementation on CVD risk factors, it becomes clear that there are benefits to nutrient. avoiding deficiency. For instance, in a trial of 148 elderly women whose baseline 25(OH)D levels of below 20 ng/

37 mL were increased to above 30 ng/mL, systolic blood pressure was significantly reduced by 9.3%. A separate study Low vitamin D status may be causal in cardiovascular of 42 outpatients with elevated blood pressure and vita- disease, primarily through its effects on blood vessels min D deficiency found similar results with recovery from and blood pressure regulation. This is hard to assess deficiency. However, in a study of healthy adults without from shorter term trials though. The dose-response curve vitamin D deficiency, whose 25(OH)D status changed from for vitamin D suggests that study designs for many trials 29 to 49 ng/mL, no effect on blood pressure was observed. may not be optimal. Similarly, no effects on endothelial function, arterial stiffness, or inflammation are seen when the baseline 25(OH)D levels are already at an average of 30 ng/mL. Frequently Asked Questions Where do we get vitamin D? In a study of people with type-2 diabetes, a change in vita- Vitamin D is unique among vitamins and hormones min D status from 14 to 25 ng/mL significantly improved because it is naturally synthesized in the skin upon insulin secretion. In pregnant women with gestational dia- exposure to sunlight. When ultraviolet (UV) radiation betes, increasing vitamin D status from 20 ng/mL to 38 ng/ penetrates the skin, it is absorbed by the cholesterol precur- mL significantly reduced fasting glucose and insulin, insulin sor 7-dehydrocholesterol and converted to previtamin D3 resistance, and total and LDL-cholesterol. Yet, in otherwise within the living cells of the epidermis. This takes more than healthy individuals with a baseline 25(OH)D level of 16 ng/ eight hours to convert to vitamin D3 and enter the dermal mL that was elevated to 57 ng/mL over six months, no effect capillary bed to be distributed throughout the body via the on insulin sensitivity was observed. bloodstream. This is also the same vitamin D3 consumed through the diet. However, vitamin D3 is inert and requires While studies don’t typically assess the risks or benefits of further metabolism in the liver to 25(OH)D, followed by 25(OH)D concentrations that are above 50 ng/mL, vitamin further metabolism within the kidneys to 1-25(OH)D, D toxicity has been associated with 25(OH)D concentrations which has a wide range of biological actions, including reg- greater than 150 ng/mL, which results in abnormally high ulation of up to 200 genes. blood concentrations of calcium (hypercalcemia) that may result in metastatic calcification of soft tissues within the body. Although dietary sources of vitamin D do exist, the prin- ciple supply is through sunlight exposure. Some notable That being said, research suggests that vitamin D is one food sources include cod liver oil (400-1000 IU/teaspoon), of the least toxic fat soluble vitamins. In most cases, toxic fatty fish (100-600 IU/3.5 oz.), and egg yolks (20 IU/yolk). occurrences are accidental and only happen after exposure Fungi synthesize vitamin D upon sunlight exposure and levels far above anything recommended or used in clinical also provide a dietary source of vitamin D2 (100 IU/3.5 trials. For instance, one case study documents these toxic oz.). In comparison, a sunbathing adult wearing a bathing effects in a 42-year old man who consumed 156,000 to 2.6 suit produces the dietary equivalent of 10,000 to 25,000 IU million IU of vitamin D daily for two years before requiring when exposed to one minimal erythemal dose of UV radi- hospitalization. Another case documents mistaken admin- ation (a slight pinkness to the skin 24 hours after exposure). istration of 2.4 million IU of vitamin D over a four-day Vitamin D synthesis is affected by a variety of factors, some period to a child. Prolonged intake of 10,000 IU per day of of which are shown in Figure 3. vitamin D poses no risk of commonly measured adverse effects to adults, even if added to a high physiological back- Is there a genetic component to vitamin D deficiency? ground of vitamin D from sun exposure. Although vitamin D deficiency is most often caused by

38 insufficient production within the skin and inadequate Vitamin D is complicated. While its primary role within the dietary intake, some research does suggest there may be a body relates to maintaining calcium balance, its reach is vast genetic component as well. In one genome-wide association and affects nearly every tissue in the body. Our understand- study of 25(OH)D concentrations in 33,996 individuals of ing of vitamin D’s role outside of skeletal health has evolved European descent from 15 cohorts, three genetic variants tremendously over the last decade and continues to grow. near genes involved in cholesterol synthesis, hydroxylation, Countless associations between vitamin D status and vari- and vitamin D transport were identified that significantly ous disease states have been observed, but intrinsic design increased the risk of being vitamin D deficient. People with flaws (some of which can be avoided through careful study all three variants were nearly 2.5-fold as likely as people design) of supplementation studies hinder our discovery of with no mutations to have 25(OH)D levels of below 30 and a causal relationship, if it exists. 20 ng/mL, respectively. Additionally, several variants of genes involved in skin pigmentation have been suggested to Cardiovascular disease is an exception, and both observa- be predictive of serum 25(OH)D levels in Caucasians. tional and clinical evidence supports vitamin D deficiency contributing to cardiovascular dysfunction primarily In a study of 652 African Americans, six SNPs in three through effects on vasculature and blood pressure regula- vitamin D pathway genes were significantly associated with tion. However, evidence on higher levels of vitamin D status serum 25(OH)D levels or vitamin D deficiency. In con- is sparse, with observational studies providing mixed results trast to Europeans, only one SNP in the region involved on its association with health. Thus, it appears prudent with skin synthesis was weakly associated with vitamin D to ensure vitamin D levels of 30-40 ng/mL, which can be deficiency. However, SNPs in CYP2R1 showed the stron- achieved with about 1,000-2,000 IU of vitamin D3 daily. ◆ gest association, which is a gene region involved in making 25(OH)D within the liver. Similarly, in a study of 2897 Vitamin D is a good example of how complex causality can Chinese persons, participants with three or four risk alleles be to determine. To discuss the epistemology of nutrition of the two variants (GC-rs4588 and CYP2R1-rs10766197) research, or just to talk about how much vitamin D you’re had a twofold increased risk of being vitamin D deficient. going to get during your summer vacation, head on over to the ERD Facebook group. What should I know?

Figure 3: Estimated Vitamin D synthesis varies considerably

Source: http://www.epa.gov/sunwise/uvimonth.html 39 Eggcellent Eggs: Is it safe for people with diabetes to eat a lot of eggs? The effect of a high-egg diet on cardiovascular risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) study—a 3-mo randomized controlled trial

40 Introduction effects on people with diabetes. Eggs are an incredibly popular protein source, especially among athletes. They also contain a host of nutrients that Although generally considered healthy for the general may be associated with reduced cardiovascular disease risk population, it is not entirely clear whether high levels of such as L-arginine and folate. egg consumption are safe for people with diabetes. This study sought to clarify whether it is okay for diabetics to Eggs were also demonized in past decades due to their eat a lot of eggs. cholesterol content, but a large amount of recent evidence indicates that they were likely incorrectly associated with cardiovascular disease. However, there remain some Who and what was studied? questions as to whether or not high-egg diets are benefi- Researchers recruited 140 overweight prediabetic or diabetic cial. While dietary guidelines of different countries many Australians who were otherwise generally healthy and were suggest different egg intakes (as seen in Figure 1), many not currently receiving any medical treatments for weight warn against those with diabetes consuming eggs regularly. control. They were also required to maintain their diabetic Some studies have implied that the choline in eggs, more and cholesterol treatment regimens whenever possible. specifically the metabolic byproduct of bacterial choline breakdown, could increased risk of cardiovascular disease, Participants met with a dietitian and were randomly but this finding is controversial. In support of these findings, assigned to consume either a high-egg or low-egg diet, and high egg consumption has been associated with increased received either eggs or vouchers of equivalent value (for the risk of cardiovascular disease in people with type II diabetes. low-egg group). The high-egg diet consisted of two eggs per day for breakfast, six days per week for 3 months. The low- However, the evidence supporting the relationship is mostly egg diet ate fewer than two eggs per week. The designed observational, and may have been influenced by the bad rap diets were energy and macronutrient-matched, and the eggs had at the time. To address these issues, the researchers protein content of the diets was equalized by instruct- conducted this randomized prospective study in an attempt ing the low-egg group to consume 10 grams of non-egg to assess whether eggs have specific negative cardiovascular lean protein every morning. This could include meat or

Figure 1: Egg guidelines for people with and without type 2 diabetes

Source: U.S. Department of Agriculture 41 high-protein vegetables like legumes. Participants also ticipants changed their medication during the trial, which received pamphlets instructing them to replace saturated could have been a confounding factor, but excluding these fats with poly- and monounsaturated fats. patients did not alter the results of the study.

Participants attended the clinic on the second week (to Saturated fat intakes decreased and PUFA/MUFA intakes ensure no weight loss occurred) and every month after- increased in both groups to a similar extent, which was ward, for three months. During each visit, the researchers expected based on dietary recommendations. Carbohydrate measured the participant’s bodyweight, waist circumference, consumption decreased in both groups, but the decrease vital signs, and asked about changes in medication. They was greater in the high-egg group, and the difference also tested blood parameters, including complete blood between the groups was statistically significant. Conversely, counts, blood glucose, and cholesterol levels. dietary fiber intake actually increased in the low-egg group, which is likely related to the recommendations that the Dietary adherence was based on five-day food diaries, and low-egg group supplement their diet with non-egg protein intakes were estimated for egg, PUFA, and MUFA consump- sources that included legumes and other high-protein veg- tion at baseline and after three months. The participants also etables. As might be expected, cholesterol intake greatly completed a variety of dietary and lifestyle surveys to assess their activity and nutritional habits as well as their general Figure 2: Trial results enjoyment of their diet at the end of the study.

The study was designed with the primary goal of assessing HDL cholesterol after three months.

140 overweight people with prediabetes or diabetes ate either 12 eggs per week, or less than two eggs per week for three months. Their diets were standardized by a dietitian, and their blood lipid levels were assessed for changes at the end of the study.

What were the findings? Twelve participants dropped out of the study (six from each group), and food logs indicated that the high- and low-egg groups pretty much stuck to their diets. Figure 2 summa- rizes the study findings. There was no significant difference in HDL cholesterol between the two groups after 3 months, regardless of diabetes status. This was despite the fact that the high-egg group had significantly higher cholesterol levels (both HDL and total) at baseline. Similarly, there was no significant difference in LDL, total cholesterol, or tri- glyceride levels between groups. There were no significant changes in weight or waist circumference either. Some par-

42 increased in the high-egg group (by about 281 mg) and may be a confounding factor in their feelings of fullness. slightly decreased (by about 36 mg) in the low-egg group. Generally, this study’s educational strategy showed some The high-egg group seemed to enjoy their diet more. This promise. Adherence to many recommendations is notori- may be related to the fact that they also reported feeling ously poor, but this study’s participants seemed to adhere more full and less hungry after breakfast. to not only the egg portion of the diet, but also to the recommendation to reduce saturated fat intake. Although not emphasized by the study authors, it is important to note Egg intake levels did not change any of the relevant mea- that meeting with a dietitian and being provided with edu- sured health parameters, but the people eating a lot of cational materials and vouchers that partially offset the cost eggs seemed to enjoy their diet and felt more full than of food may be effective in altering dietary habits. the people eating fewer eggs.

It’s important to realize that the trial participants in both groups were told to reduce saturated fats and increase poly- What does this tell us? and monunsaturated fats. Fat intake is a major determinant Based on these findings, it is unlikely that egg consump- of blood lipid levels. Hence this scenario may not extend tion poses any unique threat to people with diabetes. There as clearly to someone who eats a different type of diet that’s were very few differences in terms of cardiovascular health high in egg intake. Also, this study was financially support- measurements between high- and low-egg diets, and most ed by a grant from the Australian Egg Corporation. This of the dietary differences between the groups were slight, doesn’t negate the results at all, but it’s always important to except for cholesterol intake. recognize who funded a study when interpreting the results, since industry-funded studies tend to be more likely to However, there were some significant differences between show results supporting the industry. the groups in terms of satisfaction. Eggs for breakfast may reduce hunger and increase satiety, which could be a useful dietary strategy for people trying to reduce morning snack- These findings suggest that a high-egg diet does not affect ing. However, it should also be noted that the high-egg the health of people with diabetes adversely. Adherence to group reported more satisfaction with their diet than the the diets was high, which could be explained by education low-egg group. Dietary satisfaction contributes to feelings provided by the dietitian and the provision of vouchers. of satiety. If the high-egg group enjoyed their diet more, that

Eggs for breakfast may reduce hunger and increase satiety, which could be a useful dietary strategy for people trying to reduce morning snacking.

43 Figure 3: Comparing the The big picture two egg trials in patients Eggs offer a variety of nutritional benefits without many, if any, downsides. with type 2 diabetes However, it is often controversial whether the results of general studies can be applied to special populations. This is especially true of nutritional studies on people with metabolic disorders like diabetes. Because metabolic diseases result in disruptions of normal metabolic processes, they are often special cases when it comes to health benefits or downsides associated with specific foods or nutrients. Some previous evidence has shown that high consumption of eggs could increase the risk of cardiovascular disease in people with diabetes or other diseases, and this risk may be related to the cholesterol in eggs. This study sought to clarify whether there was some special interaction between diabetes and high-egg diets that warranted special consideration.

One of the key points of this study is that participants did not gain weight or waist circumference. This makes the results much more reliable than many dietary intervention studies that pair blood lipid measures with weight loss, which itself affects blood lipid levels. Figure 3 compares this study against the sole previous randomized trial looking at diabetic patients eating eggs, which was specifically designed to be a weight loss study. Any intervention that involves changes in multiple parameters should be interpreted with extra caution because it is difficult to determine if one intervention influenced the other. This is especially true in nutrition and human performance studies, which can be even further muddled by lifestyle changes or normal fluctuations in behavior.

There were small but significant differences in carbohydrate, total fat, and fiber consumption between the two groups in this study, but these differences were within a few percentage points of total intake. Cholesterol intake was significantly higher in the high-egg group, but was expected because of the high cholesterol content of egg yolks. More importantly, because the findings of this study were negative, meaning egg consumption did not negatively affect blood lipid profiles, these variations are even less likely to be important.

It is unlikely that eggs have major negative effects on lipid profiles in healthy or diabetic individuals.

Frequently Asked Questions Many doctors still advise patients with cardiovascular disease to avoid dietary cholesterol, including eggs. If that has been debunked, why does it still happen so frequently?

Source: Pearce et al., Br J Nutr. 2011 44 For many doctors, nutrition and dietetics are not fields that This is a difficult question to answer. Studies suggest that were emphasized during their training. This is exacerbated different hen environments can lead to different egg nutri- by the fact that nutritional science can change rapidly, and tional parameters, but current marketing trends also make the quality of research can vary wildly. Coupled with nutri- it difficult to ensure that you’re buying the “right” type of tion being a common “pop science” subject, this means eggs. For example, in some instances, simply having one there is a lot of incorrect or misleading “noise.” Based on small exit door per thousand hens in a henhouse is enough available data, it is probably reasonable to assume that eggs to declare them “pasture raised,” although the eggs of those are safe to consume, and they may even offer some protec- hens would be very different from those laid by hens who tive effects against stroke. spent most of their time in a pasture.

Could the timing of egg consumption (typically breakfast) Unfortunately, it is difficult to know what nutritional affect the results of this study? supplementation and feedstocks were used to fuel the pro- In this case, it is unlikely because the intervention lasted duction of most types of eggs. This is further compounded for three months. Shorter interventions that measure spe- by ethical implications associated with caging animals. In cific transient parameters (hourly assessments of changes general, it is probably best to buy pastured organic eggs in blood lipids in response to eating two eggs, for example) because they generally have higher nutrient values and the could be affected by the time of day in which the eggs were hens used to produce them are likely less stressed. There consumed, but because this intervention was over a relative- are also some specialized types of eggs for which the laying ly long time scale, it’s likely that the measures represent the hens are fed specific nutrients, especially those affecting overall effect of the treatment rather than that of a specific the fatty acid composition of their eggs, which may create a day. Measuring blood parameters monthly also somewhat more beneficial nutritional profile. accounts for the temporal variation in measurements, although it should be noted that many of the factors mea- What should I know? sured in this study, such as HDL, do not vary significantly If you have diabetes, it is probably okay to eat a high-egg from day-to-day. diet if it suits your lifestyle, although this study’s definition of “high-egg diet” is much lower than many people would Why is this study useful if its finding was mostly negative? consider high consumption levels. You should consult a The goal of this study was to clarify the results of observa- healthcare professional when making large changes in diet tional studies that found some differences between healthy though, regardless of whether you are diabetic or not. That people and people with diabetes in response to high-egg being said, eggs are a relatively healthy protein source and diets. This is because the few previous studies all included are unlikely to have negative effects as part of a healthy diet. certain confounding factors, such as national dietary rec- They are also good sources of a variety of essential nutrients ommendations. Therefore, the researchers conducted this (such as choline), and their usefulness as an inexpensive trial in a way that minimized the effects of those confound- protein source makes them key staples for many people. ing factors (this trial was prospective and randomized), There simply isn’t much evidence to back up the purported which makes it a somewhat stronger study. Because of this, risks associated with eating a high-egg diet. ◆ the negative findings of this study contradict that of previous studies, which indicates that more research is needed and that the scientific consensus might need to be revised. Did you know that some commercial hens can lay an egg every single day? That’s almost as often as someone posts on There are a lot of different types of eggs. Which should I be our Facebook Group. eating?

45 Do BCAAs and arginine prevent central fatigue during exercise? Branched-chain amino acids and arginine improve performance in two consecutive days of simulated handball games in male and female athletes: a randomized trial

46 Introduction tryptophan uptake. If this were the case, then BCAA supplementation would be an effective method for decreasing Exercise fatigue is complex, stemming from both central exercise-induced central fatigue via bioaccumulation of (brain) and peripheral (muscular) origins. For example, serotonin. However, previous studies on humans had found skeletal muscle under repeated stress may deplete local no ergogenic benefit. energy stores and/or accumulate metabolites that disrupt enzymatic function and therefore may not be able to pro- In theory, BCAAs have a potential in inhibiting central vide the necessary ATP in order facilitate contraction. fatigue. However, BCAA degradation leads to ammonia production. It has been postulated that the increase in The skeletal muscle may also send inhibitory feedback to the circulating ammonia may be a limiting factor in applica- brain under high effort loads via the golgi tendon appara- bility of BCAA supplementation to prevent central fatigue. tus in order to prevent injury, which may lead to muscular Research groups may have come up empty handed due to failure during resistance training. Alternatively, fatigue the ammonia accumulation that occurs during periods of may involve the accumulation of serotonin via tryptophan BCAA supplemented exercise. It has been hypothesized that uptake into the brain. Tryptophan is the biological pre- BCAA degradation into ammonia would effectively lead to cursor to serotonin, and increasing levels of serotonin are exercise decrement by affecting the brain’s central fatigue linked with drowsiness, lethargy, and changes in motivation. mechanisms. In this case, the introduction of arginine may Bioaccumulation of serotonin is the basis of the exercise-in- mitigate the proposed effects of accumulated ammonia by duced central fatigue hypothesis, which is shown in Figure 1. stimulating the urea/ornithine cycle, converting the ammonia to urea and ornithine. The rate-limiting step in central serotonin synthesis is tryptophan transport into the brain. Tryptophan enters In addition, there has not been any data accumulated on through the large neutral amino acid transporter (LNAAT). the effects of BCAA supplementation and central fatigue Therefore, it has been proposed that the competition with multiple days of controlled activity. A Taiwanese group between tryptophan and other compounds for the LNAAT proposed that BCAA and arginine would prevent the onset may decrease intra-exercise serotonin production and of central fatigue in consecutive days of exercise. This would decrease central fatigue. imply that the serotonin synthesized during exercise would induce a refractory period that would affect performance on Interestingly, branched chain amino acids (BCAAs) also use sequential day(s). the LNAAT to pass through the blood-brain barrier (BBB), making them a viable option for competitive inhibition of

Figure 1: How BCAAs might combat central fatigue during exercise

47 The short of central fatigue

When we exercise, fatty acids are mobilized in order to provide energy to produce ATP. A percentage of these mobilized fatty acids bind to circulating albumin. Albumin also binds the amino acid tryptophan. If a larger percentage of circulating albumin is binding fatty acids then there is a larger concentration of free circulating tryptophan. Tryptophan can pass through the blood brain barrier and be converted to serotonin, which may increase the rate of perceived exertion during exercise.

in a row. The simulation was essentially two thirty-minute Exercise-induced fatigue is thought to be partially caused blocks of calisthenics (bodyweight/dynamic movements) by tryptophan entering the brain. BCAAs should com- with ten minutes of rest after the first block. The end of each pete with tryptophan transport into the brain, decreasing thirty-minute block had a timed 20 meter sprint, which was central fatigue. However, human studies to date have not used as the performance metric. Heart rate was measured found such an effect. This may be due to accompanying throughout each game. increased ammonia production, which could theoretical- ly be offset by adding arginine. This study was designed Blood samples were taken for analysis before breakfast and to test this hypothesis. after the simulated handball game on both days. The free tryptophan was measured via fluorescence. Tryptophan is an aromatic amino acid with a special series of conjugated Who and what was studied? double bonds in its ring. Aromatic amino acids have specific Twenty-two elite-level handball players were recruited for emission spectra if certain wavelengths of light are shone on a double-blind, placebo controlled, randomized cross-over them. If one color of line is shone, another color shines back! experiment. This allows for calculation of their concentration in complex mixtures, like blood. Ammonia, glycerol, free fatty acids, and After initial testing the players were split into two groups, lactate levels were all determined by commercial kits. with supplements taken one hour before the game: Amino acids (AA) After the washout period (one to two weeks) the groups • 0.17 g/kg BCAA (2:1:1 leucine:isoleucine:valine) were switched and another set of simulated handball games • 0.04 g/kg arginine was performed.

Placebo (PB) This was a placebo-controlled, crossover trial where elite • An equal weight of starch as the AA group has BCAA and handball players took either placebo or BCAAs plus argi- arginine nine one hour before playing a simulated handball game for two days in a row. Twenty meter all-out sprint times A controlled diet was provided the day before the trial and were measured halfway through the game and after the the two days during the trial. Researchers controlled fluid game, and were the main study outcome. Blood chemistry intake on the second day by mandating consumption simi- and heart rate were also measured. After a one to two week lar to the amount consumed on the first day. washout period, players who took the placebo repeated the experiment with BCAAs plus arginine, and vice versa. Each group played one simulated handball game two days

48 What were the findings? The study’s findings are summarized in Figure 2. The average 20 meter sprint time was not significantly different between groups, but there were significant Figure 2: Trial results differences in improvement (about a tenth of a second) for the AA group between days. There was an improvement of about 1.3% and 1.7% between the first and second halves, while there was no improvement in the PB group.

Also, the rate of perceived exertion (RPE) was lower in the AA group, which averaged 14/20 over the two days compared to 15/20 in the PB group. Unsurprisingly, the average heart rate was not significantly different between groups.

Post-exercise BCAA levels were elevated in the AA group, but this is also unsurprising considering they supplemented BCAA before the simulation. However, plasma tryptophan remained unchanged between groups in both trials. The unchanging tryptophan levels could indicate that there was no prevention of uptake and therefore no decreases in serotonin production. The tryptophan to BCAA ratio was lower in the AA group post exercise, but the AA group had supplemented with BCAA prior to the game, which may account for this difference.

Plasma concentrations of ammonia post exercise were significantly higher in the AA group when compared to the PB group. Elevated ammonia in the AA group is expected, as there is more nitrogenous substrate for oxidation during exercise. However, not enough circulating ammonia is produced to induce exercise-mediated central fatigue. It is not possible to determine whether or not the arginine helped attenuate ammonia accumulation because there was no control for arginine in the form of a BCAA-only group.

The BCAA+arginine group showed a small but significant improvement in sprint time and rate of perceived exertion. However, there was no change in heart rate or serum tryptophan levels between the AA and PB groups. Circulating ammonia was greater in the AA group after exercise when compared to PB, but it did not appear to negatively affect sprint performance, which was better in the AA group during the second day’s sprinting.

What does this study really tell us? This study provides a great example of research that shows serious promise in rodents but does not quite pan out when the concept is applied to humans.

49 Pharmacological intervention has shown that stimulating The big picture the 5-HT1A receptor may decrease performance, but there Central fatigue in exercise is a real phenomenon. However, does not appear to be any evidence that preventing its how the brain regulates our rate of perceived exertion is synthesis, in the form of tryptophan depletion via dietary likely much more complicated than an increase in cerebral supplements, increases performance in humans. serotonin during extended activity. Interaction and regulation via other neurotransmitters, such as dopamine and This study also tells us that the accumulation of circulating acetylcholine, is almost certainly part of the larger issue. ammonia, as a result of BCAA oxidation during exercise, may not have a strong impact on performance. Researchers While it’s possible that BCAA supplementation may be a included arginine in their pre-workout formulation in order viable option for improving various aspects of exercise, as to mitigate ammonia accumulation, but there was no con- is shown in Figure 3, the evidence is mixed. Alternatively, trol group given only BCAAs to establish whether or not it they may prevent muscle protein breakdown due to exercise. had a measurable effect.

In the study’s introduction, the researchers mention that Figure 3: Evidence for BCAAs cognition and reactive abilities were metrics for central fatigue in exercise. It is curious that the researchers had improving exercise decided to use an all-out 20 meter sprint combined with circulating tryptophan as the metric for central fatigue. Other studies have used similar metrics with different exercise modalities, but it may speak to the lack of standardization as to how central fatigue is tested. For example, giving an athlete an attention capacity test while they are physically exhausted may be testing other confounding variables that have little application to an athlete’s capability to perform a sport-specific task while centrally fatigued. Furthermore, the group concluded that performance was maintained/ improved in the AA group due to delayed central fatigue, but the non-supplemented group did not have meaningful performance decrements. Because of this, it is possible that the AA group had “improved” over the second day due to some other factors unrelated to central fatigue.

Supplementing BCAAs and arginine did not improve performance in humans to the extent previous animal research suggested it would. The study design also had some issues, making it difficult to say for certain whether the added arginine necessarily lead to decreased central fatigue.

50 However, it would appear that acute ergogenic benefits have Does arginine supplementation prevent performance yet to be unequivocally established. decreases related to hyperammonemia? Clinically relevant hyperammonemia is unlikely to occur Well-trained athletes may simply have the mental grit nec- in healthy individuals with a fully functioning urea cycle. essary to overcome the feelings of fatigue associated with Ammonia levels high enough to cause cognitive dysfunction these changes in brain chemistry. This may be the mental (without artificial administration) are commonly seen in barrier athletes push through on a daily basis. If there is no people with hepatic encephalopathy due to liver failure. fuel for a muscle, or if the enzyme function is interrupted due to the metabolic environment, then a muscle simply What should I know? cannot function. However, everyone has witnessed athletes Central fatigue is a complicated issue that will require a pushing through extreme mental barriers in order to per- multi-faceted approach to prevent. form. It is unlikely that a muscle had magically repleted itself of glycogen of phosphocreatine. It is entirely possible Central fatigue is currently postulated to be a build up of that this is part of the desensitization process of central the neurotransmitter serotonin during physical activity. fatigue in well-trained athletes. Finding out what is going This may cause an increase in one’s rate of perceived exer- on in the brains and bodies of athletes during this stage of tion, causing a decline in performance. performance may hold part of the answer scientists seek.

Tryptophan is the precursor to serotonin, so scientists have Frequently asked questions tried to prevent onset of central fatigue by supplementing Will supplementing BCAAs and arginine increase exercise with BCAA which may compete with tryptophan for brain performance? uptake, but haven’t had much success. Supplementing these amino acids does not appear to have meaningful ergogenic benefit for trained athletes. However, In this study, there was no meaningful change in circulating supplementation may provide long-term benefit with tryptophan in athletes that were supplementing with BCAA respect to muscle growth and preservation, which may lead vs placebo control. Yet there was a small improvement in to accumulated performance benefits in the long term. performance in the BCAA group. The lack of an arginine control group limits the conclusions that can be made. Is it possible to be centrally fatigued and not peripherally fatigued? BCAA supplementation may have benefits, but there is little In theory, yes! If the muscles were fully repaired and energy evidence to show supplementation causes an ergogenic stores (fat and glycogen) were repleted within the muscle effect, or a substantial decrease in central fatigue.◆ then a confounding factor in performance decrement may be related to central fatigue. Now that you’ve powered through this review and are likely a bit fatigued, gather your wits and delve further into this Does the serotonin hypothesis of central fatigue apply to topic in the ERD Facebook group. strength athletes? There isn’t any controlled research that looks at this phenomenon in well-trained strength athletes. However, due to the glycogen-intensive nature of such exercise, it is much more likely that peripheral fatigue is the limiting factor in work capacity.

51 HMB-elly be gone β-Hydroxy-β-methylbutyrate (HMB) supplementation and resistance exercise significantly reduce abdominal adiposity in healthy elderly men

Introduction Muscle-building supplements are among the most popular supplements on store shelves and on the internet, often accompanied by some of the most intensive marketing campaigns. When looking at the evidence, muscle-building supplements tend to fall into three major categories: staples with ample amount of evidence behind them (e.g. creatine), new and ‘exciting’ supplements that lack evidence to support the marketing claims (too many to count), and the middle group of supplements that have enough evidence to make them interesting yet not enough to make them staples. Time tends to make this middle group fall by the wayside and out of consumer thought but every now and then a new study comes by which may revitalize the supplement. Maybe it should be a staple, maybe there are benefits which might not be significant enough to justify the price, or maybe a few more drops can be squeezed out of the cash cow before it’s forgotten about again?

β-Hydroxy-β-methylbutyrate (HMB) is a metabolite of the amino acid leucine that, along with KIC (α keto-isocaproate) and isovaleryl-CoA, mediate the effects of leucine. Approximately 5% of dietary leucine is oxidized into HMB, and HMB appears to be the main metabolite of leucine that prevents the breakdown of muscle protein. It has been studied specifically for human consumption for numerous decades, and there is no doubt it is reasonably safe and that it could affect human biology. There is

52 plenty of in vitro data to support its What’s the big deal about belly fat? mechanisms and plenty of sources available (both scientific and supple- Both obesity and waist circumference are associated with bad health out- mental) to keep it on the shelves, but it comes, namely death. So why are the authors of this study so concerned has never reached ‘staple’ status. about abdominal fat as opposed to fat mass in general?

Recently, however, two studies using Because it seems that abdominal fat may be a primary culprit in a lot of the HMB free acid form were pub- metabolic problems leading up to death. There are two kinds of belly fat: lished and found very impressive subcutaneous fat, which lives beneath the skin, and visceral fat, which is results in trained weight lifters, which packed deep in the gut and surrounds the organs. It’s been known for a seems to have renewed public interest while that visceral fat is correlated with metabolic problems such as high in the compound. These studies are cholesterol and glucose intolerance. We’ve also known for a while that not the ones to be discussed today but hypertension is sometimes more responsive to loss in visceral fat than rather a recent study suggesting HMB subcutaneous fat. So it seems that visceral fat can cause more health supplementation can reduce body fat problems than subcutaneous fat. in the elderly. Previous studies have found that HMB increases total-body The mechanism for this difference is slowly being worked out, and generally fat loss in older adults. However, no outlined in Figure 1. One reason why visceral fat may be more deadly than studies previous to this one have taken subcutaneous fat is because visceral fat inhibits the secretion of a molecule a look at the effects of HMB and resis- known as adiponectin, and reduced circulating adiponectin has been linked tance training on abdominal fat in to many of the metabolic problems seen in those with central obesity. elderly. Abdominal fat is important as it is at least as strongly correlated with The take-home here is that fat just doesn’t sit around and store energy; mortality in the elderly as body mass it’s also a metabolically active tissue. As visceral fat accumulates, one’s index, if not more so.The purpose of metabolism can be thrown out of balance. This is at least part of the rea- this study was to examine the effects son why abdominal fat is of particular importance. of 12 weeks of HMB supplementation with or without resistance training on Figure 1: How visceral fat promotes abdominal fat in elderly men. cardiovascular disease

HMB is a metabolite of leucine that helps prevent muscle breakdown and reduces total body fat in the elderly when combined with resistance training. However, previous to this study under review, no one has examined the effect of HMB plus resistance training on abdominal fat in the elderly, which is a strong pre- dictor of mortality.

53 How does DXA work?

DXA stands for dual-absorption X-ray absorptiometry. The “dual” part of the name points to the fact that two X-ray beams of different energies are used in the method. The relative absorption of each beam by tissues in the body allows one to calculate the density of those tissues and to determine the volume of specific tissues, such as fat.

One can also do this using computerized-assisted tomography (CAT scans), but one significant advantage of DXA is that it exposes the subject to lower X-ray doses.

in men than in women. Even though the original pilot study Who and what was studied? included 21 weeks of resistance training, they also limited This study was actually a re-analysis of unpublished data their re-analysis to the first 12 weeks since attrition and from a previous pilot study conducted in elderly subjects noncompliance in the study protocol significantly lowered given HMB supplementation. In that study, subjects were the available sample size past that point. The final re-anal- healthy males aged 65 or greater. All subjects had a BMI ysis had 12 men in each of the four groups for a total of 48 between 20 and 30 and were cleared of having numer- participants analyzed. ous disease states (malignant diseases, immunodeficiency disorders, and diseases related to the GI tract, cognition, cardiovascular or endocrine systems). This study was a re-analysis of unpublished data from an earlier pilot study where healthy elderly men were Subjects were given either HMB or placebo. The HMB split up into four groups: placebo or HMB supplementa- supplementation was in the form of the HMB calcium salt, tion with or without resistance training. The re-analysis at a dose 1.5g with 4g carbohydrates taken twice a day to involved calculating abdominal fat that was measured result in a total daily dose of 3g. Timing was ad libitum (up with DXA. to the subject’s discretion) as long as the full dose was taken each day, and the placebo group in this double-blind study took the same amount of carbohydrates and an equivalent What were the findings? amount of calcium (200mg twice a day) but without the As seen in Figure 2, abdominal fat mass (AFM) following the HMB. The supplemented and placebo groups were then intervention was significantly lower in the RT-HMB group divided up into two more groups: those who underwent than all other groups, and the RT-HMB group was the only supervised resistance training (RT) for three times a week one to have a significant decrease in AFM from the begin- for twelve weeks, and those who didn’t. So there were four ning to end of the study. No changes were observed in the groups in all: placebo with no resistance training, HMB other groups from beginning to end, and no differences were with no resistance training, placebo with resistance training, found among the NT-PL, NT-HMB, and RT-PL groups. and HMB with resistance training.

The authors re-analyzed the dual-absorption X-ray absorp- What does this study really tiometry (DXA) data from the pilot study in order to tell us? calculate abdominal fat. They limited their re-analysis to The results from this study suggest that in elderly men, men because excess fat tends to accumulate centrally more supplementing HMB in combination with 12 weeks of resis-

54 Figure 2: Body fat results

tance exercise is effective in decreasing abdominal fat mass. test the hypothesis that HMB plus resistance training affects In contrast, HMB supplementation without resistance train- abdominal fat would be useful to confirm these results ing and resistance training without supplementation were down the road. ineffective at reducing this potential health indicator. It should also be noted that this study was funded by Abbott However, these results should still be considered prelimi- Nutrition, which sells products that contain HMB, and so nary for a few reasons. Firstly, one should keep in mind that the possibility for a conflict of interest is there. Furthermore, this is a re-analysis of a study that was originally much more the study chair listed on the clinicaltrials.gov entry for this broad than what was reported here. The original study was study is an employee of Abbott. While no conflicts of inter- 24 weeks in all and included both men and women. This ests were declared in this reanalysis, the original pilot study re-analysis, however, was limited to only 12 of those weeks did note that the planning and execution was done in col- due to low compliance, and only limited to men. Since laboration with Abbott, and one of the authors has received central adiposity is strongly correlated with CVD risk in funding from Abbott in the past. women as well, it would have been interesting to see if these results held for the female population in the original pilot The results of this study indicated that HMB plus resis- study. See ERD #5 for an op-ed on why female representa- tance training can lead to decreased abdominal fat in tion in trials is so important yet still low. elderly men over 12 weeks, whereas resistance training or HMB alone does not. However, methodological ques- So while the results of this study were positive for the tions about this paper may warrant taking its conclusions RT-HMB arm, on should keep in mind that this is a limited with a grain of salt. re-analysis of a pilot study. A trial specifically designed to

55 The big picture primary mechanisms by which leucine prevents muscle wasting is by its conversion to HMB. HMB has been shown This study is in line with previous results showing a sig- to stimulate muscle protein synthesis to a similar degree nificant decrease (−4.4%) in fat mass in thirty-one elderly as leucine, as well as being able to decrease muscle protein adults (70 years old) participating in a resistance training breakdown. HMB is also thought to operate via enhanced program while supplementing HMB compared to resistance recovery of damaged skeletal muscle tissue via the HMG training only, after 8 weeks. However, authors of a 2013 CoA reductase pathway, and been shown to increase mito- review looking at the efficacy of HMB supplementation chondrial biogenesis and fat oxidation. Fat oxidation may in elderly and clinical populations concluded that while also be affected through Sirt1-dependent pathways. several studies have supported the efficacy of HMB supplementation to increase lean mass and strength in the elderly and clinical populations, the data are not entirely consistent This study is in line with previous studies which have and larger long-term studies are needed to clarify the prom- shown a reduction of fat mass in elderly adults with resis- ising preliminary results. Figure 3 shows the general level of tance training. However, the overall evidence on HMB’s evidence for different populations. effectiveness for fat loss is still mixed. Mechanisms of action of HMB for both increasing fat oxidation and Possible mechanisms of action include increasing skeletal decreasing muscle degradation are only partially under- muscle protein synthesis through activation of mTOR and stood at this point in time. increasing IGF-1, and decreasing protein degradation by decreasing activity and expression of the ubiquitin-proteo- some pathway. The branched-chain amino acid (BCAA) Frequently asked questions leucine is an important regulator of the protein kinase What is the difference between HMB calcium salt versus mTOR (mammalian target of rapamycin) and the main ami- free acid? no acid responsible for muscle protein synthesis. Leucine There currently is not enough evidence to determine which can be metabolized within skeletal muscle, and one of the

Figure 3: Strength of evidence for HMB-boosted fat loss in different populations

56 is better, though the free acid form (HMB-FA) may increase plasma absorption and utilization to a significantly greater degree than the calcium salt.

Does it matter when I take it? HMB is also Subjects in this study were instructed to take the doses twice a day, at any time they pleased. However, other research by thought to the same authors has shown that consuming HMB-FA 30 minutes prior to an acute bout of high volume resistance operate via training can attenuate indices of muscle damage while improving perceived recovery. The position paper from the enhanced International Society of Sports Nutrition (ISSN) (which several of the co-authors on this study had a hand in writing) suggests consuming the HMB supplement in proximity to a recovery of workout and for at least 2 weeks prior to seeing results. damaged skeletal Is this better for trained or untrained people? The greatest effects of HMB have been reported in untrained muscle tissue individuals, while the majority of studies in trained individuals have been non-periodized and unsupervised. Two via the HMG recent studies on trained individuals (using the FA-form) showed big improvements over placebo in hypertrophy, CoA reductase strength, power, and recovery. pathway, and What should I know? HMB plus resistance training reduced abdominal fat in been shown elderly men in this study, whereas HMB supplementation or resistance training alone did not. However, since this is a to increase limited re-analysis of a pilot study, more evidence is needed before firmly concluding that HMB plus resistance training reduces abdominal fat in the elderly. The results may not mitochondrial extend to younger males and females (*clearing throat and making shifty eyes towards you*). ◆ biogenesis and fat oxidation. Just like Backstreet, HMB is back! Or is it? Or do we need more trials to replicate promising results? Talk this over at the ERD Facebook forum.

57 Spicing up your workout Curcumin supplementation likely attenuates delayed onset muscle soreness (DOMS)

Introduction Curcumin is probably best known as a component of the herb turmeric. Turmeric contains 2–5% curcuminoids such as curcumin and its related compounds, methoxy- curcumin and bisdemethoxycurcumin. Curcuminoids are phenolic compounds that give turmeric (and curry) its yellow color, and have been in use as a remedy in Indian Ayurvedic and Chinese medicine for several millennia. In recent years, biomedical research has shown that curcuminoids elicit multiple biological effects that are relevant to human health, including anti-inflammatory, analgesic, anti-cancer, antidepressive, and antidiabetic properties.

58 A search for “curcumin clinical trial” in Pubmed yields no It is very well known that unaccustomed physical activ- fewer than 273 hits, underscoring the scientific interest in ity results in sore muscles, affectionately referred to as the biological activity of this chemical. Doing the same kind delayed onset muscle soreness (DOMS) amongst gym of search for cinnamon or even resveratrol yields less than goers. Exercise performed in a way to which you are not half that number, which shows that interest in curcumin is accustomed, in terms of load or intensity, range of motion, strong within the research community. or degree of muscular fatigue, will result in some muscle damage. The majority of this damage is induced during Scientific interest in curcuminoids started in the 1980s, the eccentric phase of movement, e.g., when “yielding” to when studies showed that the administration of curcumi- gravity and descending in squats. The muscle damage noids decreased the physiological markers of inflammation is characterized physiologically by soreness, tenderness, and improved morning stiffness, walking time, and swelling reduced strength, reduced stretch tolerance, swelling, and in patients with rheumatoid arthritis while also reducing increases in plasma creatine kinase (CK) and sometimes postoperative pain. Recent research has also shown some even plasma myoglobin. All of these biomarkers normally of the mechanisms through which they work. For example, peak 1–2 days after the inducing exercise bout and usually curcuminoids have been shown to increase expression and last no more than 3–5 days. activity of peroxisome proliferator-activated receptor gamma (PPAR-gamma), which mediates anti-inflammatory and This pattern underscores that the muscle damage phe- glucose uptake processes. Curcuminoids are also potent nomenon is not just a mechanical tearing damage, but a antioxidants, a property which may protect DNA from progressive biochemical phenomenon. The general process oxidation damage. Also, they inhibit activation of nuclear is depicted in Figure 1. At a cellular level, these effects are factor kappa B (NFkappaB), which further contributes to usually explained by membrane disruption of muscle fibers their anti-inflammatory effects. Furthermore, they inhibit and subsequent invasion of neutrophils, monocytes, and nitric oxide (NO) production through inhibition of induc- natural killer (NK) cells secreting cytokines, resulting in ible and endothelial nitric oxide synthase (iNOS and eNOS), pain sensation, localized edema, and increased temperature. which may also mediate anti-inflammatory effects. However, it should be noted that this process is very complex and in reality, it’s poorly understood.

Figure 1: The development of DOMS

59 [...] only one leg was trained while the subjects took curcumin and the other one was trained without taking it, acting as a control.

Thus, the purpose of the current study was to examine if subject would receive the curcumin supplement or the pla- and to what extent a curcumin supplement prevented the cebo was randomly selected for each subject. The subjects muscle damage and soreness induced by a heavy eccentric were also blinded to the nature of the supplement. exercise bout. The experiment was set up so that there would be two separate training sessions, one for each leg. In one bout, the Exercised-induced muscle damage involves some inflam- subjects would ingest capsules containing the curcumin matory processes that may contribute to DOMS. Since supplement and in the other they would ingest placebo cap- curcumin is known to have anti-inflammatory properties, sules. The supplementation protocol consisted of taking five the effect of curcumin on DOMS was investigated. capsules (containing curcumin or placebo) twice daily for 2.5 days before and after each exercise bout, with a 14-day washout period in between the exercise bouts, allowing the Who and what was studied? curcumin to clear the subjects’ bodies. Prior to enrollment, the study organizers performed a power analysis that showed that 19 subjects were needed to The curcumin supplement was actually a blend of cur- detect minimal meaningful differences in pain scores in the cuminoids—29mg of bisdemethoxycurcumin, 62.7mg of study. 19 subjects were initially included, but two withdrew demethoxycurcumin, and 964mg of curcumin, totalling before starting because they were unable to comply with the about 1060mg of curcuminoids per capsule. The place- study commitment. This left a sample of 17 adult men who bo was an inert plant cellulose compound. The curcumin were healthy, nonobese, and recreationally active, but not supplement and the placebo were put in identical opaque doing lower-body resistance training. capsules, preventing the subjects from identifying them by color, smell, or taste. Subjects in the study were instructed to do leg workouts, with or without a curcumin supplement. To control for Because eccentric exercise is known to stimulate more differences between individual responses and to allow muscle damage than concentric exercise, the exercise the subjects to be their own controls, a design was used protocol was seven sets of 10 repetitions of “eccentric leg in which only one leg was trained while the subjects took presses.” During the eccentric (or “yielding”) phase, the curcumin and the other one was trained without taking weight would be supported only by the “test leg” from full it, acting as a control. Also, to compensate for any possible extension down to 90 degrees, while during the concentric differences between dominant and nondominant legs, the (or actual lifting) phase, both legs would be used to press up leg to be trained first and the training session in which the the weight. Before the test workouts, the highest weight the

60 subjects could lift for one repetition with one leg (their “1 repetition maximum,” 1RM) was determined. For the test workout, they would do 120% of that weight for five sets of 10 repetitions followed by another two sets of 10 repetitions at 100% of their 1RM. All subjects completed this protocol. The cutoffs The subjects did a testing panel before each exercise bout (baseline), immediately after the bout (post) and again 24 and 48 hours later. The testing panel looked at used for these muscle pain both during exercise and passively, muscle tenderness and swelling, magnitude- jump performance, and biochemical markers of muscle damage and inflamma- based inferences tion including CK, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α).

The researchers assigned The data were analyzed using a technique called magnitude-based inferences, cutoffs for the differences which replaces the very binary yes/no statistical significance paradigm with a observed, and labeled them more gradual description of the likelihood of observed between-group differenc- with qualitative terms for mag- es being significant treatment effects. nitude and probability. They reported both the probability Seventeen healthy men participated in a crossover study where they were ran- and magnitude of the effects domized to exercise one leg using eccentric leg presses while taking either 2.5g using these qualitative terms. turmeric or placebo twice a day for 2.5 days before and after the exercise bout. Muscle pain, tenderness, and swelling were measured along with performance Effect sizes were reported as: on a single-leg jump test and biochemical markers for inflammation and “trivial”, 0.0–0.2; “small”, 0.2–0.6; muscle damage. After waiting 14 days, the other leg was exercised in a similar “moderate”, 0.6–1.2; “large”, manner while switching placebo for turmeric or vice versa. 1.2–2.0; and “very large”, >2.0

Probabilities were reported as What were the findings? “almost certainly not” <0.5%; “very unlikely”, <5%; “unlikely”, First of all, all 17 subjects completed the study, so there were no issues with com- <25%; <75%, “possibly”, <75%; pliance. Furthermore, the increases in muscle soreness and plasma CK across “likely” >75%; “very likely”>95% both groups in the study confirmed that the exercise protocol was adequate to and “almost certain”, >99.5 cause muscle damage.

Thus a statistical effect (i.e. As seen in Figure 2, curcumin reduced exercise-induced pain in single-leg squats, between-group difference) single-leg vertical jumps, gluteal stretch, and walking downstairs, with moder- could be described as an ate-to-large (0.6-2.0) effect sizes at the 48-hour time point and for all of those “unlikely” “moderate” effect, if except walking downstairs for the 24-hour time point; effect sizes ranged from there was <25% probability of moderate (0.6-1.2) to very large (>2.0) and probabilities of “likely” (>75%). an effect of 0.6-1.2 effect sizes.

Curcumin improved first-jump performance from immediately post-exercise to 24 hours and 48 hours post-exercise, relative to the placebo group (by 15.4% and 15.8%, respectively), whereas the difference between the curcumin and placebo group were trivial during second and third jumps.

61 Curcumin likely (>75%) had a small lowering effect on on IL-6 acutely and at 48 hours post-exercise, but inhibits serum CK 24 and 48 hours post-exercise, relative to pla- it at 24 hours post-exercise. IL-6 can be considered a good cebo. While curcumin did not affect TNF-α, it influenced guy as well as a bad guy, depending upon circumstanc- IL-6 levels in a rather peculiar manner: It induced a small es—the acute exercise-induced increase in IL-6 has been increase in the IL-6 levels relative to placebo immediately proposed as an effector of some of the beneficial metabolic post-exercise and 48 hours post-exercise, and decreased it effects of exercise (here and here), while chronically elevat- 24 hours post-exercise (all with probabilities of “likely”). ed IL-6 is generally considered catabolic to muscle and is associated with a range of morbidities and mortality in the Finally, there was no effect of curcumin on swelling or ten- elderly. So, it’s possible that curcumin potentiates the acute derness. However, this could be a signal-to-noise issue, as beneficial metabolic effects of exercise through IL-6. the study was designed with statistical power for detecting differences in pain, not in swelling or tenderness. If the vari- This study extends findings about curcumin’s effects on ation in these measures were higher than for pain, which eccentric exercise in animals. The pattern of curcumin’s the authors hint at, this could mean that the study is simply effects on IL-6 may indicate a somewhat novel finding in underpowered to detect differences in these measures. humans.

Curcumin decreased most measures of pain relative to placebo, and improved first-jump performance in a 3-jump test. There were also minor effects on biochemi- Figure 2: Improvements in leg cal markers of inflammation and muscle damage. pain from taking curcumin

What does the study really tell us? From a technical point of view, the study is very well execut- ed, with a proper a priori sample size calculation, blinding, a strong study setup, and sound statistical methods and reporting.

As far as the biology goes, the study shows (not surprising- ly) that curcuminoids do in fact inhibit part of the muscle damage induced by unaccustomed exercise, in terms of subjective markers, such as pain; pseudo-objective markers, such as jumping performance (pseudo-objective, because it also depends on pain); and objective markers, such as serum CK. This has been shown before in animal studies with eccentric exercise.

One finding that stands out is the effect of curcumin on IL-6. It appears as if it increases the exercise-induced effects

62 The big picture esting for performance reasons would be individuals who are subjected to physical workloads to which they cannot A large number of studies have looked into ways to inhibit realistically be accustomed. This could be the case for DOMS with a variety of anti-inflammatory and analgesic ultra-endurance athletes, who may be working continual- compounds, but it turns out that the inflammation in mus- ly for 3, 4, or 5 days in row in competitions, an amount of cle damage is somehow tied to the remodelling of muscle. work for which it is impossible to be 100% conditioned. In some cases, and maybe most of them, inhibiting soreness of muscle damage may also partially inhibit the adapta- It could also be relevant for athletes in competitions with tion, i.e., hypertrophy. As there are no longitudinal human tightly packed events or military personnel, as they some- resistance or endurance training studies with curcumin times have to maintain muscle function during sustained administration, we cannot know if the inhibition of muscle physical activity with little chance of rest. There’s no room damage provided by curcumin also inhibits the adaptation for muscle soreness, when on long-distance recon mission. that we sweat so much to achieve, making it hard to draw For these individuals, reducing soreness and muscle damage any conclusions from the effects. is as relevant as sustained performance is important, even in the light of possible impaired adaptation. In reality, of course, muscle damage is not that big of a problem for regular trainees, because muscles develop a Lastly, this trial may actually have underestimated the resistance to damage through what is known as the “repeat- potential effect of curcumin on DOMS, as additives that ed bout effect”, which is described in the FAQ section. So increase absorption (such as piperine, show in Figure 3) if exercise intensity is increased gradually, as it typical- were not used. ly should be, severe muscle soreness will hardly ever be encountered. The only people to whom this could be inter-

Figure 3: Absorption of curcumin with and without piperine (in rats)

Source: Shoba et al., Planta Med. 1998 63 ularly membrane disruption and activation of the resident This study provides evidence that curcumin may be muscle stem cells, the satellite cells, and the training and useful for pain and some aspects of performance in the training-induced response should not be considered “train- short-term. Longer-term studies are needed to ascertain ing” per se. the effects of chronic curcumin consumption on muscle growth. What is the “repeated bout effect”? Muscle damage only occurs with unaccustomed exercise. So when the muscle gets used to a given stimulus, mus- Frequently asked questions cle damage and DOMS no longer manifest. In fact, it has Is muscle damage bad? been shown that a single bout of exercise can provide some No, muscle damage is not inherently bad. But it’s not degree of protection against another bout completed nine inherently good, either. With resistance training, protein months later, without any exercise in the interim. Exactly synthesis is elevated only for approximately two days after what mediates this protective effect of exercise is poorly training. When muscles are sore for four or five days, it understood. does not mean that muscle growth is occurring throughout this period as muscle protein synthesis has been repeatedly What should I know? shown to increase for only 48 hours. Rather, it keeps you Unaccustomed exercise, particularly high-force eccentric from training again and thereby providing the muscle with exercise, is known to induced muscle damage and soreness, a new stimulus. If anything, muscle damage or DOMS is a known as DOMS. In this study, subjects went through an marker of how accustomed you are to a given stimulus. And exercise protocol designed to induce muscle damage in this “accustomedness” dissipates with time. Alas, the best order to test if curcumin supplementation would reduce way to get sore from a workout is to do it infrequently. the degree of muscle damage, strength deficit and soreness caused by the exercise. The study showed that curcumin What is the relevance of such an extreme eccentric exercise administration reduced exercise-induced soreness and pre- muscle damage model? vented some aspects of exercise-induced strength deficits. ◆ One could ask if having untrained subjects do 7 set of 10 repetitions of maximal eccentric contractions is even related to exercise. Truth be told, it’s not. The stimulus is intended What can’t curcumin do? Well, a lot. But it certainly has a to create a degree of muscle damage and must therefore be larger evidence base than most other supplements. If you grossly unaccustomed, unlike what would be considered take it and notice effects, let us know in the ERD private a typical exercise prescription. Muscle damage models are forum. used to research basic behaviors in muscle biology, partic-

No, muscle damage is not inherently bad. But it’s not inherently good, either.

64 INTERVIEW: Shawn Wells, MPH, RD

Shawn Wells, MPH, RD, CISSN has a unique blend of knowledge in the field of performance nutrition and supplementation. Mr. Wells attended UNC-Chapel Hill, earning a Master’s degree in Nutrition and minor in Exercise Science. His education along with credentials of Registered Dietitian, Certified Sport Nutritionist (CISSN), and board member of the ISSN, distinguished him as an expert in sports nutrition.

If you’re into supplements, you will love this interview with Shawn Wells. There’s so much information that it’s split into two, with the next issue concluding the interview.

For those who don’t know, Shawn has extensive experience in formulating supplements for big companies, likely some of the ones you’ve tried in the past few years. Shawn, how did you go from a practicing Chief Clinical Dietitian to being in the thick of the supplement industry? In 1993, I hurt my back and couldn’t play basketball my freshman year of college. I was obsessed with basketball and played every waking moment so the injury devastated me. I was pursuing a business degree and I started reading Muscle Media 2000 (MM2K) and IronMan magazine…as well as a book by Dr. Michel Colgan called Optimum Sports Nutrition (this was 1993). Dr. Colgan talked about bloodwork, working with Olympic athletes, amino acid stacks for GH, etc. and at the time there were few quality supplement studies. There were few “sports nutritionists” let alone a true degree in that. I became transfixed with this field and the wide-open possibilities on performance. I started working out and along came CREATINE from EAS called Phosphagain (creatine and protein blend) and then Phosphagen (creatine monohydrate).

I had incredible results and I was hooked...It wasn’t all boron, smilax, etc. There were supplements that could truly affect performance. This revelation and fervent desire led to me working at GNC, working out five days a week, reading every magazine and book I could (there wasn’t much internet data available then). But there were a few “gems” like the supplement review guide Bill Phillips (highly biased, but still a great read with several revisions). As a look to the future, a book from 2001 was the penultimate gamechanger though by Stout and Antonio’s Sport Supplements (not biased and groundbreaking, the true “bar”, and a forerunner to things like examine.com). I thought this was all

65 great, but never thought it was possible to do this as a career. as a rep, a writer, a formulator, etc. and it just grew (along This is no career in this “stuff”. I was at a doctor getting a with my passion). While at UNC Chapel Hill (Go Heels!), checkup and I told him about my new passion at the ripe I took Exercise Sports Science classes with my Nutritional age of 20. He drew a lifeline for me…from 20-80 and said, Biochemistry and a Registered Dietitian track. Years later, “You have ALL of this”…pointing to that 60 year gap…”Why Chapel Hill now has a sport nutrition degree (Dr. Abbie not be happy?” His words. A stranger’s words truly changed Smith-Ryan of ISSN fame teaching)…I took the road less my life path. And I think about that often. Our words have travelled and created my path. While it was difficult, I truly profound impact to make or break people’s dreams (I rec- appreciate where I am and how it’s shaped me. I also think ommend reading the it is great that so Four Agreements many have all of on this front if you these new oppor- have not). So I had I have held the role of tunities. What I to get 2 years’ worth would’ve given to of pre-requisites Chief Clinical Dietitian do a sports nutri- to even get in to a tion degree! master’s program with over a decade in in Nutrition at an So now, I am sci- esteemed school like acute and skilled nursing entist, clinical UNC Chapel Hill. dietitian, business- care, which grounded man, educator…I The advisor told me, have been blessed “You’re a business beyond belief. I student. Not a science my ethics and practice of do what I love person. You can’t do every day (and 26 hours of credits patient focused care. thank God for a semester of pure that encouraging advanced sciences with several labs classes per week. You’ll doctor I mentioned above). As a result I have a network of fail and fail miserably.” staggeringly brilliant and amazing people around me that make me better and challenge me constantly. Geniuses. You Remember what I said about words? I thought about his know in the past few months I’ve talked with or spent time words EVERY SINGLE DAY. EVERY DAY. A 4.0 GPA later with people I used to worship on the internet from aca- in 1.5 years (not 2.5) and admission to Chapel Hill for my demia & industry: Master’s later I was on my way. Luckily I did not listen to that man. He could’ve robbed me of my dream. All those William Llewellyn, Jose Antonio, Patrick Arnold, Rick people I said I’ve met, worked with, am friends with, have Collins, Marv Heuer, Ralf Jäger, Jacob Wilson, Gabe learned from, do business with…all of it could’ve been gone. Wilson, Hector Lopez, Dana Houser, Michael Colgan, Stolen from me. By one man’s words. I also owe a big Anthony Almada, Daniel Amen, Joey Rodrigues, Tim thanks to Ryan and Jeremy DeLuca during all of this school- Ziegenfuss, Layne Norton, Erica Stump, Bruce Kneller, ing of science classes, reading, working out and finding Mike McCandless, Rob Wildman to name a few (and there’s my passion, Bodybuilding.com forum was what built me. I lots more). Along the way I’ve met amazing new people (to become a guru there and worked my way into companies me) like Ryan Lowery, Mike T Nelson, Mike Roberts, Abbie

66 Smith-Ryan, Mike Ormsbee, Paul Cribb, Colin Wilborn, patient focused care. I then fulfilled the position of CEO of Bill Campbell, Brett Hall, Dom D’Agostino, Jeff Volek, Ben Zone Halo Research, a consulting group for 20+ supplement Esgro, Brett Hall, Lee Brown, Stephanie Wilson, Laurent companies, and gained significant notoriety in the industry. Bannock, Alan North and Bernadette (One Life Radio), Joel This opened the door to becoming an accomplished author, Marion, Josh Bezoni, Lawrence Ballenger, Ben Pakulski formulator, and clinician. This led to a huge opportunity in (BPAK), Peter Thornton, Ryan DeLuca, The “Dynamic Duo”, 2011, when I took my experience and passion to Dymatize Sol (here at Examine) and so, so, so many more. Nutrition, becoming Director of R&D. Dymatize is now owned by Post, and has cemented its role the global leader Seriously…staggering. Just writing this out. Wow. I am truly in finished product research and innovation with over 200 blessed to know and learn from these people. And these are SKUs in more than 50 countries. just 10% that came out of my mind off the top. I think part of my success is due to having a unique blend of knowledge After the Post Holdings acquisition, I was acquired in my in the field of performance nutrition and supplementation. own right, by the top non-GMO & natural dietary supple- As I attended UNC-Chapel Hill, earning a Master’s degree ment company in the industry, BioTRUST Nutrition, as in Nutrition and minor in Exercise Science. My educa- their Vice President of Research and Development and tion along with the credentials of Registered Dietitian and recently was promoted to their Chief Scientific Officer Certified Sport Nutritionist (CISSN), distinguished me as (CSO). I travel the globe looking for the next great ingredi- an expert in sports nutrition. I have held the role of Chief ent, doing research, and assembling innovative formulations Clinical Dietitian with over a decade in acute and skilled with experience in every channel of distribution/sales. I also nursing care, which grounded my ethics and practice of work on Intellectual property, patenting/licensing, and sub- I travel the globe looking for the next great ingredient, doing research, and assembling innovative formulations with experience in every channel of distribution/sales. I also work on Intellectual property, patenting/ licensing, and subject matter expert work for legal cases. I am an editor of the JISSN, or the ISSN Advisory Board, have written textbook chapters…it’s been a wild ride.

67 ject matter expert work for legal cases. I am an editor of the are constant changes and quite frankly many places see it as JISSN, or the ISSN Advisory Board, have written textbook a point of confusion like understanding tax codes. chapters (New ISSN textbook)…it’s been a wild ride. Many comanufacturers (the manufacturer that is not What are some of the most important factors that differ- “in-house” is called a comanufacturer) source materials entiate a high-quality supplement manufacturer from a that have “dry labbed” COAs and specs…meaning they low-quality one? don’t really test them (they type up results on a laptop…a Good Question, one key factor is the people associated dark secret known in the industry as ”dry lab”)…knowing with them. Do they have a strong R&D and QC team? At the comanufacturer won’t test them or use dry labs to get Dymatize, we had a top-notch team and now at BioTRUST, intentionally false results as well. Many labs in the industry I have over 10 people working with me on my team includ- are dry labs, allowing companies/comanufacturers to get ing people with experience from VitaCost, Bodybuilding. cheap ingredients and make them “compliant” by “testing com, EAS, Dymatize, Alix, Genesis Today, etc. People that out” even though they were never tested at any point. There are Certified Food Scientists, Organic Chemists…incredible, are very few truly “good guys” like Chromadex, Covance, amazing team. Three Directors work with me: a Director of EuroFins, etc. You pay for what you get. We test out raw Compliance, Blake Stanhouse, a Director of R&D, Andrew materials upon benchtop level, piloting (scale up), and full Quintanilla, and a Director of Quality Control, Bart Conley. production, then test out the finished good/product with I am proud of this team and the expectation is excellence each lot. It’s time consuming (adding weeks or months to every day. You ask how to know whether a product is effec- your product release schedule) and VERY expensive. There tive/efficacious or quality or not…there’s so much to say are so many scams on the manufacturing side. Many of the there. And you need experts to know even where to look. ingredients use inferior testing methods to test out as well, So having experts that know CFR regulations of the FDA, like titration, UV, etc. and not HPLC. They show 60% active having top tier comanufacturers that are not just cGMP, but like the label and COA shows, but test out with HPLC and NSF (auditing and consulting in the industry), with great it is 1%...things like that are scams and technically are legal. NSF and FDA audits says “this comanufacturer is the gold FDA is getting wise to these archaic methodology loopholes, standard” and using them…that’s a good place to start. I but it’s tough to say what’s what. would say 8 out of 10 comanufacturers are not meeting FDA regulations, especially with forthcoming FSMA regs. There Another key is doing stability work on your products,

Many labs in the industry are dry labs, allowing companies/comanufacturers to get cheap ingredients and make them “compliant” by “testing out” even though they were never tested at any point.

68 both in real time and “accelerated” work. This shows if your product will meet label claims (typically two years) throughout the life of the product. Vitamins or probiotics It’s the oldest for example, will often need 300% of label claim as an input to meet full label claim throughout shelf life. You think that trick in the affects raw ingredient costs to make a product? YES! But the best companies, labs and comanufacturers work this way. supplement Which is probably less than 20% of companies. It is bad how many companies cut corners and are really encouraged or book to list thrive on cutting those corners.

The market is shifting though. Testing is getting more “fairy dusted” nuanced. Pharmaceutical companies or large risk-averse companies with project management and legal rigor in expensive place are buying big companies. Consumers are taking to testing, 3rd party websites are testing, regulatory bodies are ingredients in a stepping up, compliance consultants are being more visible and it’s great. There is a leap of faith here to some degree, blend and have but reputation for excellence, quality of people on the team, transparent labels (no proprietary blending), are all key to the majority trust from the consumer. of the blend The ingredients need to be non-proprietary blended and transparent, without a doubt. It’s the oldest trick in the supplement book to list “fairy dusted” expensive ingredients in be a cheap a blend and have the majority of the blend be a cheap ingredient. It’s manipulative and a deceptive to the consumer. I ingredient. would love to see “prop blends” banned quite frankly…it would be a huge win for consumers. How else can the con- THEN we can talk about the next great thing. Chances are sumer know if they’re getting the study-backed (examine. you’re not getting what you’re paying for (the dream) and com backed) dose/amount? you’re getting things you don’t (heavy metals, metabolites, toxins, etc.). So while many are looking for the next great supplement, it should be less of a concern than 1. Is what you’re tak- Although some supplements have a huge research base (such ing what is on the label? 2. Is what’s on the label safe for as creatine), supplement stacks are rarely tested together. How you? 3. Do they test for heavy metals, metabolites, toxins, do you approach this issue from a formulation standpoint? impurities, etc.? 4. Is it hidden in a proprietary blend and I know some companies cobble together animal and in vitro fairy dusted? 5. Did they use ingredients that have human, studies, but you seem to have a better grasp of good science. non-disease population data? 5. Does that human data Formulations should be based on healthy human data, not relate to the form, dose, method of administration and the animal and not in disease states. The ingredient if quoting population that applies to you? 6. Is there finished good research, should also be in that specific form, dose/amount, data…that applies to #1-6 as well…

69 method of administration, frequency of administration I don’t think most people know what goes into actually (e.g. 3 times a day at 500mg), etc. Then, there should be making a supplement. It’s not like being a mad scientist, just 1-2 studies on the finished products to truly make strong throwing different things in test tubes and seeing what hap- claims. You don’t know whether ingredients are counter- pens. How would you describe your actual day to day job? ◆ productive together or work as well as each individual study states. Doing real trials on your finished products in a rep- [TO BE CONTINUED IN ERD #8] resentative population to whom you’re selling product to, is what the FDA, FTC and private litigators is demanding. Yet few companies are getting this kind of research. Luckily, the companies I have worked with support these efforts. Mr. Wells has held the role of Chief Clinical Places like PubMed and clearly, Examine.com are now “go Dietitian with over a decade in acute and skilled to’s” for formulators (and savvy consumers). Looking at nursing care, grounding his ethics and practice of each ingredient in the filter I mentioned, then finding and sourcing that ingredient…and testing it out yourself to see patient focused care. Fulfilling the position of CEO if it is what is claimed. I love the surge of branded ingredi- of Zone Halo Research, a consulting group for ents that cost more, but are getting great data. Companies supplement formulations, he gained significant like Interhealth, Nutragenesis, MTI, Compound Solutions, notoriety in the industry. etc. are getting study after study and helping the companies build 1. Effective formulations 2. Provide marketing with As an accomplished author, formulator and cli- backed structure/function claims 3. Assure some level of nician, in 2011, Shawn took his experience and quality as they are invested in the ingredient, like you are. I passion to become Director of R&D at Dymatize recently, built a formulation with 3 branded ingredients… Nutrition. Dymatize Nutrition, now owned by Post, and that’s it…6 patents, about 10 human studies. It’s great. has cemented its role the global leader in finished Consumers are starting to see the value “in less is more” and product research and innovation with over 200 care what is going in their body. Much like a shorter ingre- products in more than 50 countries. dient declaration on a food product is best, that mindset is carrying over to formulations in supplements. Shawn was recently acquired by the top non-

As far as in vitro, I rarely use that data except when drilling GMO & natural dietary supplement company in down into mechanism of action, sometimes it’s the only way the industry, BioTRUST Nutrition, as their Vice to deduce that, but NEVER, EVER use that as sole means of President of Research and Development and has making structure function claims or marketing copy. Never. since been promoted to Chief Scientific Officer But if in vitro, then animal, then toxicology animal data, over the Compliance, R&D, and Quality Control then pilot studies, and full scale randomized double blind departments. Mr. Wells travels the globe looking placebo controlled studies all point in the right direction for the next great ingredient, doing research, and of efficacy, dose dependency curves, etc. It’s a process that assembling innovative formulations with experi- leads down a path of best scientific practice. It is a process ence in every channel of distribution/sales. though and only getting to animal data is not something to make claims off of…and, again, best case is testing your For more on Shawn Wells, MPH, RD, CISSN, find finished formula. him on LinkedIn.

70 Ask the Researcher

James Heathers, Ph.D.

In the “biohacking” and athlete communities, HRV (heart (2003). Until that point, I was primarily an experimental rate variability) is increasing in popularity. Can you psychologist. When I read this paper, I had an overwhelm- explain the essentials of HRV for us? And how exactly did ing sense of needing to know more. Most of the research you get into it? I’ve done since then has been squarely focused on how to At rest, the heart rate isn’t static. Instead, it fluctuates over increase, measure, or modify HRV. a number of different timescales. While there is some research interest in the longer timescales, when most people What are some potentially interesting uses of HRV, as well say HRV they actually mean short-term or high-frequency as pitfalls to look out for? HRV, the fluctuations in the heart rate due to breath- There are many uses for it in research, but for the person ing. There are two primary reasons this is interesting to on the street, athletic monitoring is one of the best uses for researchers: first, heart rate is cheap and easy to measure HRV. The reasons for this are threefold. and simple to analyse. Second, the modulation of the respiratory rhythm in the heart is almost entirely managed by 1. You actually have something to measure. People who the efferent branch of the parasympathetic nervous system. train hard really knock the hell out of themselves. During actual athletic activity, your meaningful HRV Now, the parasympathetic nervous system is mostly respon- is essentially zero, and after significant overtrain- sible for managing the ‘resting’ functions of the body, so ing, you’ll see a reasonably predictable decrease. It’s the parasympathetic outflow to the heart is a good indica- a change that’s very easy to detect compared to the tion of the presence or absence of many forms of systemic emotion or mood-based lab research I’ve done. When stress. We see HRV reductions in laboratory stress tasks, in you’re not well recovered, your HRV will tell you. patients with anxiety disorders, in chronically underslept 2. Athletic monitoring can happen every day, more than people, in at-risk diabetics, and many more. Because of the once a day, or even continuously through the whole relationship with breathing, we can track sleep apnea with it. day. Even casual athletes are pretty comfortable with The list goes on. self-measurement and tracking, if not biometric data then at least workout times, weights, reps, speeds and How I started with individual research I can trace back distances. Measurement is the cornerstone of progress, to an individual paper I read during my MSc.: Pollo et.al. and heart rate measurement is easy.

71 3. Athletic monitoring compares measurements of HRV Some supplements are touted as improving HRV. Which internally rather than externally. That is, instead of ones hold promise, and how does the effect compare to prac- looking at the differences between people (like my tices such as meditation? research often has to), you are looking at variation The short answer is: forget it. within your own nervous system over time. And you have hundreds and hundreds of data points to form The long answer is: let’s make a quick distinction between predictions with. improving your HRV and improving some aspect of your health and wellness, which we then measure by assessing HRV. While I don’t necessarily recommend you do this, if you’ve got a way of measuring HRV you can watch this happen- In that sense, your best ‘supplement’ for improving HRV ing to yourself: go to the gym twice a day for a week, and in the short term is sleep and in the long term is aero- hit over 90% 1RM on any exercise in every single workout. bic exercise. If there’s a dietary supplement which has a Take readings every morning and every day before lunch. well-supported claim to increase HRV in a healthy popula- By day four or five, you should see a clear and present lack tion, I haven’t heard about it. Fish oil, for instance, is all over of HRV, which will proceed through the whole day. the map. There’s a few studies which seem to show gener- alised increases with EPA/DHA consumption. Not only did The biggest pitfall is simple - people make claims that sim- they not pan out well over time, but the animals models ply can’t be supported. Marketing is everywhere, even in seem to suggest that the mechanism which is involved in research. While there are a lot of outlandish claims made, any potential increase isn’t the parasympathetic outflow, it’s two of my personal bugbears are claims that things which actually changing the nature of the conduction within the aren’t parasympathetic modulation can be measured by heart itself. If you have any kind cardiac arrhythmia, this HRV - sympathetic outflow, for instance, or blood lactate, or might actually be a problem. The specifics of this are well ‘readiness’ measures. These things are poorly supported and beyond casual interest, but if anyone’s interested, my col- worse than that, poorly defined. Worst of all is the claim league George Billman wrote a huge paper on this topic a that HRV is some kind of overall ‘health barometer’, and few years ago. that if it goes up, it’s exclusively good. This thinking isn’t just wrong, it’s dangerous. People use heuristics like this so they (Note: this does not make fish oil ‘bad.’ I’d refer people to can measure physiology without thinking about it. the Examine.com page on fish oil at this point.)

Worst of all is the claim that HRV is some kind of overall ‘health barometer’, and that if it goes up, it’s exclusively good. This thinking isn’t just wrong, it’s dangerous.

72 Meditation is probably a better candidate for increasing iThlete monitor we rigged to do research with - so techni- HRV, but there’s a huge caveat - meditation often is a mech- cally it’s Simon’s innovation. Newspapers are rarely happy to anism for modifying breathing. Now, the slower and more make distinctions like that.) deeply you breathe, the more HRV you get. Does this mean that the normal physiological consequences of your whole New developments? Oh yeah, lots. I usually work on about life and circumstances that would normally set your HRV ten to twenty papers at the same time - I get bored easily are being affected? No, it just means you’re breathing more and need things to jump between. slowly, and because of the specific activity of your lungs and circulatory system, you have more HRV. It’s like adjusting I’m working on some new methods of removing the respi- the odometer on a car manually then claiming the car has ratory signal from the ECG, which show a great deal of been driven further; promise ... I didn’t it’s confusing the typi- think they’d work very cal measurement with well until I tried them the actual meaningful [...] sometimes the and was pleasantly outcome. To my annoy- surprised. In other ance, I’ve seen people heart decelerates a lot words, from just your citing my own work as Polar chestband sig- ‘proof’ that meditation more abruptly than nal we can not just ‘increases HRV’ - that’s measure your heart not what it shows at all. it accelerates. A lot of rate, but respiration as well, due to the That being said, I think HRV work ignores this shape of the ECG there’s reasonable evi- changing over time. dence to show that rather inconvenient Commercial man- meditation can teach ufacturers are way people to modify their behind when it comes autonomic state over fact, but that doesn’t to this family of time. I’d go for medi- methods. Most respi- tation over any given make it go away. ratory monitoring supplement, but I’d also solutions are terrible. go for sleep and aerobic capacity over meditation. I’m also working on a method of using not just the distances between the heart rate cycles, but WITHIN the cycles. Experiments are simple, physiology is complicated. The Generally we just calculate the cycle rate, in beats per min- straightforward statement of “XYZ increases HRV” take an ute, or in ms (you can do HRV with both). What we don’t extraordinary amount of work to sustain. No nutritional do is break the individual cycle down into phases and look supplement I’ve seen fits that bill. at how the individual phases change over time.

You’re quite the innovator in this field. Have you personally Oh, and I’m trying to better quantify the relationship had any new developments in the past year or two, and has between respiration and heartbeat, because it isn’t a simple the HRV field changed much in that time? linear relationship. In fact, sometimes the heart decelerates (That one doesn’t really count as my innovation, that’s the a lot more abruptly than it accelerates. A lot of HRV work

73 ignores this rather inconvenient fact, but that doesn’t make it go away. One or more of these techniques may end up in your Polar watch.

One thing that I’m interested in but haven’t had the chance to do yet is [...] the work HRV and some related measures into a computer game / virtual environment. When that gets done properly, it’s essentially going to add ‘backlash’ biofeedback to 2D/3D simulations of anything. against As far as change is concerned, HRV is a two-speed field.

One speed is lightning fast. There are people who are working on total- useless ly new techniques of analysing HRV, which involve some fairly high level concepts: non-linear dynamics, fractals, entropy. These papers are often fitness published in physics journals, they’re no joke. There are excellent biomedical engineers working on new monitors and new monitoring environments monitors has all the time. A lab at MIT developed a method of pulling your heart rate straight out of a webcam picture. Samsung has released a research platform started. This for developers called Simband, who can now use the platform to build their own software applications without having to build their own hardware. And is a natural there’s the guys at Bitalino, who have made a second-generation research grade ECG machine that you can buy for a few hundred dollars. That’s right, part of the you can now buy a REAL ECG for the same price as a normal fitness monitor! You can replicate about 80% of my lab work with the machine they’ve built, for about a hundred times less money. business

However the other speed is where most of the biological sciences are at, and lifecycle of that includes exercise physiology, sports science, and nutrition. People are doing, by and large, quite unimaginative work and using techniques which any product, were established largely in the 80s and 90s. And sadly, a lot of research makes basic mistakes when it comes to methodological control and and it’s also research design. It drives me crazy, especially when I have to review those papers and write the same comments I’ve written before. generally the

We’re now in a funny situation where some of the more intelligent biohackers I’ve talked to - the ‘amateurs’ - have a better theoretical grounding than the best thing to ‘professionals.’ The reason for this is simple: their model for working is a lot more collaborative, and they listen. While I don’t do any self measurement spur genuine at all, I am very happy that the Quantified Self and biohacker communities exist - they push the envelope in a field that’s been static for too long. innovation.

Do you see HRV being more widely used in clinical and personal settings,

74 five to 10 years from now? Why or why not? est in high-fat foods, and social deficits. Research into the Definitely more widely used in both. neurobiological and genetic components of eating disorders has really been heating up over the past few years, and some The why is simple: wearable technology and computing is of the recent results are fascinating. just starting to come off a great wave of popular interest, and hundreds of new devices which collect heart rate have Lusi et.al. found a curiously increased prevalence of nickel been designed and marketed. allergy in overweight and obese patients. Unfortunately, I could write a laundry list of methodological problems with At the consumer level, a lot of these devices have failed (yes, the study, but at the very least we get to talk about a nov- failed) and the ‘backlash’ against useless fitness monitors el obesogenic mechanism for once, which doesn’t happen has started. This is a natural part of the business lifecycle often these days. Happily, the study is very easy to replicate, of any product, and it’s also generally the best thing to spur so we’ll see what happens with the role of nickel in a year or genuine innovation. Once everyone has stopped trying to so when someone does a large-scale analysis of the allergy build another fitness monitor, they’ll start to think what prevalence or a proper RCT with an overweight population. better information can we measure? When the “me, too!” nature of hardware development stops, we’re going to see Now, here’s a topic that’s received a lot of interest - Abregon- some real progress. My methods, for instance, are a long Tito et.al. and Morton et.al. both addressed separate way away from being implemented in your FitBit, but there questions of ancestral nutrition with respect to gut aren’t any technical barriers to that - it’s just that engineers microbiota. Both papers collected stool samples from hunt- don’t know enough physiology to try new things. They will er-gatherer societies and compared them to each other (and soon, though. Engineers are good like that. to samples from developed world guts). To cut a very long story short, the differences are stark and engaging, and it Clinical devices, however, are just starting to really come seems that you can eat paleo, but you can’t actually BE paleo on the market now since the development takes a lot lon- ... unless you’re a hunter-gatherer. I’m going to pay close ger and is expensive. HRV has pretty good diagnostic value, attention to the research in the human microbiota over the and access to accurate measurement just keeps getting bet- next few years, because I get the feeling it’s just getting start- ter. I met a guy at a conference at the end of last year who ed with what it can tell us about optimal nutrition. set up some clinics in developing countries using nothing but smartphone-based medical equipment. He said the heart Thanks James, for giving us some important points to think rate monitor was about 100% reliable, and it got more use about regarding HRV, plus some other very interesting than everything else put together. That’s the thin end of the topics. HRV is a topic with a wide gulf between experts and wedge for all future heart-rate based technologies. those who make claims. And as research develops in the coming years, we look forward to speaking with you again. ◆ Outside of HRV, what’s captured your interesting nutrition-wise in the past few months? So much. I’ll confine myself to just a few. James Heathers, Ph.D, is an Endeavour Research Fellow in Electrocardiology at Poznan University Cui et.al. examined the functional outcome of knocking out of Medical Science. His research revolves around a transcription factor called ESSRA. The mice developed a measurement issues in heart rate and heart rate series of behaviours which have a lot of similarities to eating variability. He writes about health, science, medi- disorders: compulsive and rigid behaviors, reduced inter- cine and bioethics.

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