PECANS AND GOOD HEALTH

A REVIEW OF THE RESEARCH

Following are highlights of several research studies, followed by general recent nutrition policies and guidelines that demonstrate that nuts (and pecans in particular) can be part of a healthy diet.

Antioxidant-Rich Pecans enriched diet was similar to the these data provide some Protect Against Unhealthy Step I diet but replaced 20 evidence for potential Oxidation in the Body percent of calories with protective effects of pecan pecans). After four weeks on consumption in healthy Haddad, et al. A Pecan one diet, they then switched to individuals. Enriched Diet Increases Y- the other diet. Tocopherol/Cholesterol and Another key research finding, Decreases Thiobarbituric Results: In the laboratory beyond the reduced level of Acid Reactive Substances in analysis of blood samples from blood lipid oxidation, was that Plasma of Adults. Nutrition the research subjects, the the various phytochemicals Research. August 2006. researchers found that the found in pecans seem to be 26:397-402. pecan-enriched diets protective of the pecan’s high significantly reduced lipid levels of unsaturated fat. All These findings are from the oxidation (by 7.4 percent) unsaturated fats in foods can second phase of a research versus the Step I diet. be prone to oxidation project designed to evaluate Oxidation levels were themselves (which some may the health benefits of pecans. evaluated using the TBARS describe in foods as rancidity). Researchers analyzed blood test, which measures oxidation The analysis found that samples from study products. The researchers also pecans, while high in participants (a total of 23 men found that blood levels of unsaturated fat, are “self- and women between the ages tocopherols were higher after protective” due to their vitamin of 25 and 55) who ate two participants were on the pecan E content (tocopherols) and diets: one that contained diet. Cholesterol-adjusted relatively high content of pecans and one that did not. plasma gamma-tocopherol in complex phytonutrients, some Participants were randomly the study participants’ blood of which have been identified placed on either the American samples increased by 10.1 as proanthocyanidins, or Heart Association’s Step I diet percent (P < .001) after eating condensed tannins, which are or a pecan-enriched version of the pecan diet. The recognized for their ability to the Step I diet. (The pecan- researchers concluded that slow the oxidation process. Results: The researchers tocopherol to cholesterol be found that the pecan diet determined. significantly lowered total Pecans Double the cholesterol (11.3% compared Results: The researchers Cholesterol-Lowering with 5.2% on the Step I diet) concluded that the pecan- Effectiveness of a Traditional and LDL cholesterol (16.5% enriched diet significantly Heart-Healthy Diet compared with 6.7% on the raised blood levels of gamma Step I diet). In fact, the pecans tocopherol compared to the Rajaram et al. A doubled the cholesterol AHA Step I diet. This is due Monounsaturated Fatty lowering ability of the Step I to the high amounts of Acid-Rich Pecan-Enriched diet. The pecan diet increased naturally occurring gamma Diet Favorably Alters the HDL cholesterol levels tocopherol (a unique form of Serum Lipid Profile of whereas the Step I diet vitamin E) in the pecans, said Healthy Men and Women. decreased HDL unfavorably. Dr. Haddad. The gamma The Journal of Nutrition. Triglycerides also were tocopherol-to-cholesterol ratio September 2001. 131:2275- significantly lower with the was higher on the pecan- 2279. pecan diet. Although the enriched diet compared to the pecan diet contained more fat control diet. According to Dr. This eight-week, rigidly (39.6%) than the Step I diet Haddad, gamma tocopherol is controlled, crossover study (28.3%), participants did not an important antioxidant conducted at Loma Linda gain weight. nutrient. Studies have shown University compared the effect that it may benefit intestinal pecans have on blood Pecans Raise Critical Serum health and have a protective cholesterol levels to a Vitamin E Levels: May effect against prostate cancer. traditional low-fat American Support Prostate and Heart Association (AHA) Step Intestinal Health Pecans Increase Fiber and I diet. Dr. Sujatha Rajaram Nutrient Intake and her colleagues evaluated Haddad et al. Effect of a 23 healthy men and women Pecan Rich Diet on Plasma Barloon et al. High Fat (nine women and 14 men Tocopherol Status. Pecan-Based Diet as between the ages of 25 and 55) (Abstract published in the Effective as Step I Diet to with normal to mildly elevated March 2001 FASEB Journal. Maintain Plasma Lipid and blood cholesterol levels. Research presented at the Lipoprotein Responses. Participants were randomly April Experimental Biology (Research presented at the selected to consume either an 2001 meeting). May 2001 American Heart AHA Step I diet or a “pecan” Association Conference on diet (which consisted of An analysis of the Vitamin E Arteriosclerosis, Thrombosis replacing 20 percent of content of blood was done and Vascular Biology). calories from the Step I diet using samples from the same food with pecans). The diets research participants studied Researchers at Texas A&M were then reversed for a by Rajaram et al (see previous University discovered that a second four-week period. study). Loma Linda’s Dr. Ella heart-healthy diet containing Total serum cholesterol, high- Haddad evaluated effects of a pecans can help control density lipoprotein (HDL or pecan-enriched diet on serum specific biomarkers of heart “good”) cholesterol and gamma tocopherol levels for disease risk as effectively as triglyceride levels were this study. Because the pecan- the AHA Step I diet. Forty measured at the end of each enriched diet actually lowered hypercholesterolemic men and diet period. cholesterol levels, the women between the ages of 22 researchers determined it was and 71, all of whom had critical that the ratio of plasma already been eating a relatively low-fat diet, participated in the in concentrated amounts. study. During the eight-week, According to Dr. Ron Results: The researchers randomized, controlled feeding Eitenmiller, pecans contain as found that adding pecans to a trial, participants were placed much as 95 milligrams of plant self-selected diet lowered LDL on either the AHA Step I diet sterols per 100 grams – 90 cholesterol levels by six or an isocaloric but higher-fat, percent of which is in the form percent and total cholesterol by pecan-based diet. Since this of beta-sitosterol. Beta- four percent among those who was not a crossover study, the sitosterol has been cited in ate pecans. Dietary fat, research participants ate one multitudes of animal and monounsaturated fat, diet or the other, but not both. human research studies as a polyunsaturated fat, insoluble food component that competes sugar, magnesium, and energy Results: According to with the absorption of also were significantly higher researchers Dr. Rosemary cholesterol in the body, and in the pecan group. However, Walzem and Jessica Barloon, thus has the ability to lower despite the fact that the pecan there were no significant blood cholesterol levels. diet contained more overall fat differences in negative risk According to the researchers, and calories, body mass factors (e.g., c-reactive protein by increasing consumption of indexes and body weights were levels or lipoprotein pecans (or peanuts), a person unchanged in both groups. size/density) between diets. could easily raise the plant However, the researchers sterol levels in the diet to the Mediterranean Diet found that the pecan-rich diet point where health effects have Including Nuts More significantly increased been proven. Effective than Low-Fat Diets participants’ levels of dietary for Weight Loss fiber, thiamin, magnesium, Pecans Improve Heart copper and manganese and Disease Risk Factors McManus et al. A actually changed dietary randomized controlled trial copper and magnesium intakes Morgan et al. Pecans Lower of a moderate-fat, low- from inadequate (on the AHA Low-Density Lipoprotein energy diet compared with a diet) to adequate (on the pecan Cholesterol in People with low-fat, low-energy diet, for diet). Normal Lipid Levels. weight loss in over-weight Journal of the American adults. International Journal Pecans: A Concentrated Dietetic Association. 2000. of Obesity. 2001. 25: 1503- Source of Natural Plant 100: 312-8 1511 Sterols Dr. Wanda Morgan at New Researchers from Brigham and Eitenmiller et al. Sterol Mexico State University Women’s Hospital and Content of Peanuts, Pecans conducted a study in which 19 Harvard School of Public and Peanut Products. men and women with normal Health evaluated 101 (Research presented at the blood lipid levels were divided overweight men and women to 2000 Institute of Food into two groups, both of which determine the effects of a low- Technologists meeting). consumed self-selected diets. fat diet (20% calories from fat) One of the groups served as a versus a moderate fat diet After conducting laboratory control group and ate their (35% calories from fat, nutrient analyses, researchers regular diets for eight weeks primarily mono-unsaturated fat at the University of Georgia (without eating any nuts). from foods such as nuts, olive (UGA) have determined that Subjects in the pecan test and canola oils). The study plant sterols – widely group, however, supplemented was a randomized, 18-month researched and touted for their their regular diets with ¾ cup trial (in a free-living situation) cholesterol-lowering ability – of pecans (about a handful) for that had participants follow are found naturally in pecans eight weeks. one of the diets or the other. Both diets were low in Foods such as nuts – an “Overall, our results suggest saturated fat and participants important dietary source of that higher intakes of vitamin were instructed to consume vitamin E – may significantly E from foods (compared with between 1,200 and 1,500 decrease the risk of death from lower intake from foods) may calories. stroke, according to this study be associated with a lower risk Results: After the 18-month from the University of of death from stroke. Vitamin study period, participants in Minnesota. The E is a free radical scavenger the low-fat group had a mean epidemiological study and thus may help prevent weight gain of about six evaluated the relationship oxidation of LDL, an pounds; their body mass index between antioxidant vitamin important step in the increased, as did their average intake and stroke. The atherosclerotic process. waist circumference. researchers tracked the food However, those on the intake and health outcomes of Frequent Nut Consumption moderate fat diet decreased 34,492 post-menopausal Iowa Lowers Heart Disease Risk mean body weight by about women (participants of Iowa nine pounds while also Women’s Health Study) for a Kris-Etherton et al. The decreasing their body mass number of years. Participants Effects of Nuts on Coronary indices and waist responded to questions Heart Disease Risk. circumferences. Only 20 regarding their demographic Nutrition Reviews. April percent of those in the low-fat characteristics, including 2001. 59:4: 103-111. group were participating in the medical history and health weight loss program after the habits. A food frequency This review of the literature 18-month trial, compared with questionnaire was used to looked at various clinical and 54 percent of those in the gather information about their epidemiological (population) moderate-fat group. The diet. Upon completion of the studies that addressed a authors concluded, “A study, the researchers possible connection between moderate-fat Mediterranean- evaluated the possible consumption of nuts and their style diet, controlled in energy relationship between stroke effect on coronary heart offering an alternative to a and intake of antioxidant disease (CHD) risk. The low-fat diet with superior long- vitamins. review included several term participation and significant “epi” studies that adherence, with consequent Results: The researchers were published prior to the improvements in weight loss.” found that death from stroke preparation of this review Moreover, those on the was 60 percent lower among paper. moderate fat diet were better those consuming the most able to adhere to the weight vitamin E from foods when Results: The authors of this loss program than those who compared to those who review paper concluded “there followed a low-fat diet. consumed the least. These is consistent evidence, findings are of particular especially from Antioxidants in Pecans May importance as the epidemiological studies, that Offer Stroke Protection Recommended Daily Intake nuts have a strong protective (RDI) for vitamin E was effect against CHD. Evidence Yochum et al. Intake of recently raised for both men from a growing database of Antioxidant Vitamins and and women. This population clinical studies indicates that Risk of Death from Stroke in research suggest that eating part of the cardioprotective Postmenopausal Women. foods like pecans – which are effect of nuts is due to their American Journal of Clinical rich in a number of healthy favorable effects on plasma Nutrition. 2000. 72: 476-483 nutrients, including vitamin E lipids and lipoproteins, owing – helps increase levels of to their fatty acid composition vitamin E in the diet. The when they replace dietary researchers concluded, saturated fat and/or Pecans Are Most carbohydrates.” Fraser et al. A Possible Antioxidant Rich Nut Protective Effect of Nut Hu et al. Frequent Nut Consumption on Risk of Xianli Wu et al. Lipophilic Consumption and Risk of Coronary Heart Disease. and Hydrophilic Antioxidant Coronary Heart Disease in The Adventist Health Study. Capacities of Common Foods Women; Prospective Cohort Archives of Internal in the United States. The Study. British Medical Medicine. 1992. 152; 1416- Journal of Agriculture and Journal. 1998. 317: 1341-5. 1424. Food Chemistry. May 2004. 52 (12), 4026-4037 This epidemiological study Loma Linda University found that frequent nut researchers evaluated diets of This landmark study examined consumption was associated over 31,000 non-Hispanic the antioxidant capacities of with a reduced risk of fatal white California Seventh-Day over 100 different kinds of coronary heart disease and Adventists participating in the foods, including fruits, non-fatal coronary heart Adventist Health Study, a vegetables, nuts, dried fruits, disease. Participants in the prospective cohort study. spices, cereals, infant, and well-known Nurses’ Health Participants completed other foods. Antioxidants are Study (between the ages of 34 questionnaires on their dietary substances that have and 59) answered a survey lifestyle, including food intake. been shown to delay aging and regarding their dietary intake On the food frequency decrease the risk of cancer, (including nut consumption) in questionnaire, participants heart disease, and neurological 1980, 1984, 1986 and 1990. categorized food intake on a diseases like Alzheimer’s. The questionnaire grouped nut scale of 1-8, ranging from consumption into four “never consume” to “more Results: Using a method that categories including: almost than once per day.” The had been shown to be a good never, 1-3 times per month to association between diet and indicator of the total once per week, 2-4 times per coronary heart disease (CHD) antioxidant capacity of foods week and greater than 5 times events was determined via called ORAC (Oxygen Radical per week. The responses were various methods. Absorbance Capacity), evaluated and analyzed to researchers found that pecans determine if an association Results: The researchers rank highest among all nuts between nut consumption and found that those who and are among the top risk of fatal heart disease and consumed nuts more than four category of foods to contain non-fatal coronary heart times per week had fewer fatal the highest antioxidant disease existed. CHD events and non-fatal capacity. heart disease events compared Results: The researchers to those who consumed nuts Pecans Aid Weight Control found that women who less than once a week. consumed one ounce portions Researchers concluded, “Our Sabaté, Joan. Nut of nuts frequently (more than 5 data strongly suggest that the Consumption and Body times a week) had a 35 percent frequent consumption of nuts Weight. American Journal of lower risk of coronary heart may protect against risk of Clinical Nutrition. disease, than those women CHD events. The favorable September 2003. Vol. 78, who rarely ate nuts. The fatty acid profile of many nuts No. 3, 647S-650S authors concluded, “These data in one possible explanation for and those other such an effect.” A review of pecan and other epidemiological and clinical nut research suggests that nuts studies support a role for nuts like pecans can aid in weight in reducing coronary heart loss and maintenance. disease risk. (USDA) and the U.S. lipoprotein cholesterol, Results: The review cited Department of Health and triglycerides and most studies indicating that nut Human Services (HHS) also importantly, diabetes control). consumption may increase unveiled a revised food metabolic rates and enhance pyramid to illustrate the Specifically, the guidelines satiety. When used in importance of eating a variety recommend that intakes of conjunction with a low-fat of foods, including healthful carbohydrate and diet, nuts also offer increased fat, including nuts and olive monounsaturated fat should flavor, palatability and texture oil, and for limiting foods with account for 60 to 70 percent of that can lead to greater dietary added sugar, saturated fat, and calories, and 15 to 20 percent compliance, according to the trans fatty acids. The new of caloric intake should come review. icon, named My Pyramid Food from protein. Nuts are cited as Guidance System, is based on a good source of NUTRITION the 2005 Dietary Guidelines, monounsaturated fat. POLICY/GUIDELINES which were released in January ’05 and represents the latest AHA Supports Nutrients science available on the role of Found in Pecans U.S. Dietary Guidelines Tout diet and nutrition in a healthy Importance of Protein and lifestyle. Krauss et al. AHA Dietary Other Nutrients in Pecans Guidelines. Revision 2000: Nutrition Guidelines for A Statement for Healthcare U.S. Department of Diabetic Diets Emphasize Professionals from the Agriculture and U.S. Monounsaturated Fats Nutrition Committee of the Department of Health and American Heart Association. Human Services. Dietary Franz et al. Evidence-Based Circulation. 2000. 102: Guidelines for Americans. th Nutrition Principles and 2284-2299. 2005. 6 Edition. MSNBC Recommendations for Interactive, Jan. 12, 2005 Treatment and Prevention of The American Heart Diabetes and Related Association’s updated heart- The government’s newest Complications. Diabetes healthy dietary guidelines Dietary Guidelines for Care. January 2002. 25: echoed recommendations Americans (January 2005) say 148-198. made in the government’s Americans should vary their 2000 Dietary Guidelines for choices of protein “with more Diabetics can now select a diet Americans. The newest AHA fish, beans, peas, nuts, and rich in monounsaturated fat in guidelines specifically advise seeds.” For the average lieu of diet that is low in fat consumers to limit their intake person, that means eating and rich in carbohydrates, of saturated fat and to about 5 ½ servings from the according to guidelines from “substitute grains and “meat and beans” category the American Diabetes unsaturated fatty acids from each day. Pecans and other Association. An expert panel fish, vegetables, legumes and nuts are included in this of 12 scientists formulated nuts” in its place. The AHA category because of their high these evidence-based guidelines note that dietary concentration of important guidelines, which emphasize factors that can lower “bad” nutrients and proteins. One individualized diets and wide- cholesterol include serving of pecans (about 20 ranging food choices. What consumption of pecan halves) is the same as led to this change is research polyunsaturated and eating about 2 ounces of meat that showed there are benefits monounsaturated fats when (or 6 thin slices of ham) but to a diet high in substituted for saturated fats. with less saturated fat and no monounsaturated fat (i.e., The guidelines suggest nuts cholesterol. The U.S. improvement in high-density (such as pecans), which are Department of Agriculture rich in polyunsaturated fat and insulin sensitivity. Compared impact on lowering total and monounsaturated fat and low with saturated fat, MUFAs LDL cholesterol is derived in saturated fat, can play a role lower total and LDL from reduced intakes of in a hearth-healthy diet. cholesterol levels, and relative saturated fats and cholesterol to carbohydrate, they increase as well as weight reduction in Kris-Etherton et al. HDL cholesterol levels and obese persons. Diets high in Monounsaturated Fatty decrease plasma triglyceride complex carbohydrates and Acids and Risk of levels.” Nuts are cited as a fiber are associated with Cardiovascular Disease. food this is high in reduced mortality rates from Circulation. 1999. 100: monounsaturated fats and low CHD and other chronic 1253-1258. in saturated fats. diseases.” Incorporating pecans into the diet may help According to this scientific Van Horn et al. Fiber, consumers reach AHA’s statement from AHA’s Lipids and Coronary Heart recommended fiber intake of Nutrition Committee, “there is Disease: A Statement for 30-45 grams per day. epidemiological evidence that Healthcare Professionals dietary monounsaturated fats from the Nutrition (MUFAs) have a beneficial Committee, American Heart effect on the risk of coronary Association. Circulation. heart disease (CHD). 1997; 95: 2701-2704. Moreover, evidence from controlled clinical studies has This AHA statement offers shown that MUFAs favorably support for research by affect a number of risk factors Barloon et al (reference for CHD, including plasma earlier) which found that lipids and lipoproteins, factors participants on a pecan- related to thrombogenesis, in enriched diet consumed higher Research compiled by the National vitro LDL oxidative levels of dietary fiber than Pecan Shellers Association. susceptibility (compared with those on an AHA Step I diet. www.ilovepecans.org polyunsaturated fats), and Says AHA, “The greatest