36 ENDOCRINOLOGY NOVEMBER 15, 2009 • INTERNAL MEDICINE NEWS Dietary Nuts and Pulses Beneficial in Diabetes

BY KATE JOHNSON diets, there were SMD reduc- pleted the study, with a similar tions in fasting blood of dropout rate in each group. M ONTREAL — A diet rich in 0.32 and in glycosylated blood An intention-to-treat analysis pulses and nuts can improve protein of 0.27. revealed that HbA1c levels were glycemic control in type 2 dia- Based on these results, “we significantly lower in the nuts- betes patients to within ranges would expect about a 0.48% re- only group, compared with the seen with pharmaceutical inter- duction in HbA1c, and this level -muffin combination group vention, researchers reported at of benefit approaches that seen (6.88% versus 7.02%), although the World Diabetes Congress. with acarbose, exceeds the the latter was not significantly A meta-analysis of 41 trials of [Food and Drug Administration] lower than the muffin-only pulses, either alone or com- proposed clinically meaningful group (7.06%), Dr. Kendall said. COM bined with low-glycemic or . threshold of 0.3%, and lies at the There was a significant dose re- high-fiber diets, noted im- lower limit of efficacy of what sponse seen in LDL cholesterol OTOLIA

proved markers of long-term /F you might expect for oral level, which fell by 0.19 mmol/L glycemic control (Diabetologia agents,” Dr. Sievenpiper said. in the full-nut group, compared INKA

2009;52:1479-95), reported Dr. ©T The nut study randomized with full-muffin group. John Sievenpiper of the risk fac- Dietary intake of pulses—such as chickpeas, beans, lentils, and 117 patients with Weight change from baseline tor modification center of St. peas—can help diabetic patients reduce postprandial glycemia. to consume either 75 g nuts, 38 was not significant, although Michael’s Hospital, Toronto. g nuts and 1.5 bran muffins (150 there was a trend toward more Another study, also conducted some of the first studies in the and various other antinutrients kcal per muffin), or three weight loss in the nuts-only by his group, found that 75 g of 1980s showing similar results. “which may act as enzyme in- muffins daily for 3 months. Nut group. This was particularly in- mixed nuts daily for 3 months “I believe implicitly that pa- hibitors,” Dr. Sievenpiper said. portions included a mix of al- teresting, given that more daily improved blood lipids and tients do respond to dietary ad- “The effect is to decrease starch monds, cashews, macadamias, calories were consumed in this glycemic control in patients with vice. In fact, the degree of re- digestion and absorption and pecans, pistachios, walnuts, and group (2,072 kcal), compared type 2 diabetes, compared with sponse for type 2 diabetes is quite therefore postprandial glycemia.” peanuts. All treatment portions with the muffin-only group a mixture of nuts and muffins, often as great as it is for some of In his meta-analysis, “modest were equivalent to 475 kcal/day (1,932 kcal), Dr. Kendall said. or muffins alone. “Whatever the medications, if people com- improvement in medium to and were designed to maintain Previous studies by Dr. your favorite nut or form of nut, ply,” the professor of human nu- long-term glycemic control was rather than decrease body Kendall and his colleagues, as it’s good to get it into your diet,” trition and medicine at Edgar seen when [pulses] were given weight. The primary outcome well as other studies, have said Dr. Cyril Kendall of the National Center for Diabetes Re- alone or in combination with di- of the study was change in shown this same effect, he said. University of Toronto’s depart- search in Dunedin, New Zea- etary maneuvers to reduce the HbA1c and serum lipids. “What we’ve found is that nuts ment of nutritional sciences. land, said in an interview. “Most glycemic index in the diet.” The patients’ baseline char- are not entirely digested and Both researchers acknowl- physicians don’t believe that peo- The analysis included 11 trials acteristics were similar across there’s an excretion of about edged long lists of industry re- ple will adhere sufficiently to di- that examined consumption of the groups. They ranged in age 15%-20% that are simply not lationships: serving on advisory etary advice to make a significant pulses alone, which noted an from 61 to 63 years, 75% were absorbed and pass through the boards for a number of food difference, and because physi- overall decrease in standardized men, ethnic backgrounds were gastrointestinal tract.” companies, as well as the Inter- cians are not convinced, neither mean difference (SMD) of 0.71 in diverse, and body mass indexes Previous unpublished work national Nut Council, and the are their patients. It takes an en- fasting blood glucose (FBG) and ranged from 28.8 to 30.3 kg/m2. by his group has shown that Canola and Flax Councils of thusiastic physician to get an en- 0.62 in serum insulin. Similarly, All patients were being treat- nuts have favorable effects on Canada, and receiving consul- thusiastic patient.” 19 trials looking at consumption ed with oral hypoglycemic med- postprandial glucose response tant fees from Pulse Canada. Dietary pulses such as chick- of pulses in low glycemic index ication, and their mean HbA1c to common such “These are very nice, confir- peas, beans, lentils, and peas are diets noted an SMD decrease of level was 7.1%. Baseline lipid as white , potatoes, rice, matory studies,” commented characterized by a low glycemic 0.28 in glycosylated blood pro- profiles were balanced across and . “You get a graded re- Dr. Jim Mann, an endocrinolo- index, high fiber content, high teins—either hemoglobin A1c or the groups, and the mean dura- duction in glycemic response gist who was not connected to levels of amylose and resistant fructosamine. And in 11 trials tion of diabetes was 7-8 years. depending on the dose of nuts,” the analyses, but performed starches, and vegetable protein examining pulses in high-fiber A total of 100 patients com- Dr. Kendall said. ■ Exercise Added to Diet Improves Weight Loss in Diabetes

BY KATE JOHNSON ple tend towards a lot of high-glycemic Adelaide (Australia). The HC diet had Glycemic control also showed similar carbohydrates, which is not good,” Dr. 55% and 20% protein, with improvements in all groups, with a mean M ONTREAL — The focus of lifestyle Mann, a professor of the goal of providing 0.8 g/kg per day of drop of 2.1 mmol/L in fasting glucose, interventions for type 2 diabetes should and medicine at Edgar National Centre protein. The HP diet contained 40% car- 4.7 mU/L in serum insulin, and 1.25% in be on combining weight loss diets with for Diabetes Research in Dunedin, New bohydrate and 35% protein with the goal hemoglobin A1c. exercise, according to new research. Zealand, said in an interview. of providing 1.2 g/kg per day of protein. “This really does reiterate the impor- Weight loss is similar for either high- Previous research has indicated that Both diets consisted mainly of whole tance of achieving dietary weight loss in carbohydrate (HC) or a high-protein there is some evidence that during foods, with dairy, animal, and vegetable this patient group,” Mr. Wycherley said. (HP) diets—with the addition of exercise weight loss, consumption of a high-pro- sources of protein, and whole grains Recent research has shown similar re- fueling the benefits of either diet, re- tein diet may potentiate the impact of re- rather than processed carbohydrates. sults of exercise and high-protein versus ported Thomas Wycherley at the World sistance exercise, compared with a high- Overall, there was a mean weight loss of high-carbohydrate diets in nondiabetic Diabetes Congress. carbohydrate diet, Mr. Wycherley said. about 10 kg (10%) across all four groups. subjects, he said, but until now this has not The study, which was partially funded His study compared HC and HP Subjects in the HC and HP groups lost a been studied in patients with diabetes. by the Pork Cooperative Research Centre weight-loss diets, with and without a re- mean of 8.6 and 9.0 kg, respectively. How- “In response to the diabetes and obe- in Australia, showed a nonsignificant trend sistance training program, over 12 weeks ever, for those who also attended exercise sity epidemic, we’re seeing an increase in toward better outcomes in patients on an in 83 men and women with type 2 dia- sessions three times a week, the weight loss the prevalence of alternative diets such HP rather than HC diet—an observation betes, 59 of whom completed the study. was greater (10.5 kg for HC and exercise, as high-protein diets. This has raised that makes sense for certain patients, re- The groups had similar dropout rates. and 13.8 kg for HP and exercise). some conjecture in the literature re- marked Dr. Jim Mann, an endocrinologist The subjects were a mean age of 56 All treatment groups had similar im- garding the optimal dietary composition who was not connected to the study. years, with a mean baseline body mass provements in traditional cardiovascular to deliver the most therapeutic benefits “I think there is a reasonable body of index of 35. The diets were equally en- disease risk markers, with a 10% drop in to this patient group—in particular sur- evidence that a high-protein diet may ergy restrictive (6 MJ/day for women both systolic and diastolic blood pressure, rounding the carbohydrate to protein have some benefits [over a high-carbo- and 7 MJ/day for men) and equal in fat and drops of 0.47 mmol/L in triglyc- ratio,” he said. hydrate diet] for some people with the content (about 25%), said Mr. Wycherley, erides, 0.67 mmol/L in total cholesterol, Mr. Wycherley did not declare any rel- metabolic syndrome because these peo- a research assistant at the University of and 0.37 mmol/L in LDL cholesterol. evant conflicts of interest. ■