Jody Randolph

Effect of grape seed extract on blood pressure in subjects with the metabolic syndrome

This study was undertaken to determine whether grape seed extracts (GSE) that contain powerful vasodilator phenolic compounds lower blood pressure in subjects with the metabolic syndrome. The subjects were randomized into 3 groups-(a) placebo, (b) 150 mg GSE per day, and (c) 300 mg GSE per day-and treated for 4 weeks. Serum lipids and blood glucose were measured at the beginning of the study and at the end. Blood pressure was recorded using an ambulatory monitoring device at the start of the treatment period and at the end. Both the systolic and diastolic blood pressures were lowered after treatment with GSE as compared with placebo. There were no significant changes in serum lipids or blood glucose values. These findings suggest that GSE could be used as a nutraceutical in a lifestyle modification program for patients with the metabolic syndrome.

Black Beans, Fiber, and Antioxidant Capacity Pilot Study: Examination of Whole Foods vs. Functional Components on Postprandial Metabolic, Oxidative Stress, and Inflammation in Adults with Metabolic Syndrome

Beans (Phaseolus vulgaris) contain bioactive components with functional properties that may modify cardiovascular risk. The aims of this pilot study were to evaluate the ability of black beans to attenuate postprandial metabolic, oxidative stress, and inflammatory responses and determine relative contribution of dietary fiber and antioxidant capacity of beans to the overall effect. In this randomized, controlled, crossover trial, 12 adults with metabolic syndrome (MetS) consumed one of three meals (black bean (BB), fiber matched (FM), and antioxidant capacity matched (AM)) on three occasions that included blood collection before (fasting) and five hours postprandially. Insulin was lower after the BB meal, compared to the FM or AM meals (p < 0.0001). A significant meal × time interaction was observed for plasma antioxidant capacity (p = 0.002) revealing differences over time: AM > BB > FM. Oxidized LDL (oxLDL) was not different by meal, although a trend for declining oxLDL was observed after the BB and AM meals at five hours compared to the FM meal. Triglycerides and interleukin-6 (IL-6) increased in response to meals (p < 0.0001). Inclusion of black beans with a typical Western-style meal attenuates postprandial insulin and moderately enhances postprandial antioxidant endpoints in adults with MetS, which could only be partly explained by fiber content and properties of antioxidant capacity.

Potatoes, Glycemic Index, and Weight Loss in Free-Living Individuals: Practical Implications

Background: The role of glycemic index (GI) and foods with negative attributes related to GI as part of a weight loss regimen has not been thoroughly assessed in free-living individuals. This study examined the effects of a dietary prescription for energy intake modification, GI, and potato consumption on weight loss, dietary prescription adherence, body composition, and glucose control in a free-living, self-selecting overweight population. Methods: Ninety overweight (body mass index [BMI] 29.6 ± 3.9) men and women were randomly assigned to one of 3 groups for 12 weeks. Two groups were counseled to reduce their energy intake by 500 kcal/day and consume diets that were predominantly composed of either low- or high-GI foods (low glycemic index energy reduced [LGI-ER] or high glycemic index energy reduced [HGI-ER] diet, respectively). The third group received no energy restriction, GI provision, or nutritional counseling. All groups were instructed to consume 5–7 servings of potatoes per week. Changes in weight, body composition, glucose tolerance, and triglycerides were determined at baseline and 12 weeks. Results: There were no significant differences in weight loss or changes in body composition between the groups; however, modest weight loss and body composition changes were seen from week 0 to week 12 for all groups (p < 0.05). Difficulty achieving the prescribed GI diets was evident in this free-living setting. There were no significant changes within or among treatments for fasting concentrations of triglycerides, glucose tolerance, insulin, or insulin sensitivity. Conclusions: The results indicate that in a free-living population of men and women, weight loss is associated with energy intake reduction. Potato intake did not cause weight gain and following either a high- or low-GI dietary prescription was difficult for free-living subjects, emphasizing the complex nature of changing dietary patterns.