The Impact of Select Nutraceuticals and Whole Foods on Parameters of Cardiovascular Health

While cardiovascular health claims are commonly made for diverse foods and supplements, in many cases the evidence supporting the claims is limited. The overall aim of this dissertation was to examine the effects of isolated bioactive compounds from foods and whole foods on select indicators of vascular health in populations at high risk for cardiovascular disease. Four independent projects were completed. The first study examined the effects of three different dietary intakes of a lychee fruit extract for two weeks on microvascular function, platelet function and blood lipids in a population of postmenopausal women. No significant changes in these selected markers of vascular health were detected. The second project examined the effects of walnuts on microvascular function, platelet function and blood lipids in a population of hypercholesterolemic postmenopausal women. Significant positive changes in microvascular function were documented in the walnut group compared to the control group after daily walnut intake for four weeks. The third project examined acute effects of two forms of resveratrol on microvascular function and platelet function, as well as on plasma concentrations of resveratrol, in postmenopausal women. Significant improvements in microvascular function were noted with a resveratrol-arginine complex, but not with trans-resveratrol. Plasma resveratrol concentrations significantly increased with both resveratrol supplements; however, a significant positive correlation between plasma resveratrol and microvascular function was only noted with resveratrol-arginine complex. Additionally, a significant decrease in arachidonic acid induced platelet aggregation was noted with resveratrol-arginine complex. The fourth project was a study that assessed changes in microvascular function, plasma nitrate/nitrite levels, circulating progenitor cells and platelet reactivity in overweight or obese adolescent males in response to the acute and short term consumption of a freeze-dried strawberry powder. The major findings from this study include a significant increase in microvascular function acutely after a week of daily consumption of strawberry powder, an increase in plasma nitrate/nitrite acutely and short term, as well as an increase in HDL after seven days of strawberry supplementation. These studies collectively suggest that incorporating isolated well-characterized bioactive compounds, as well as select whole foods into a daily diet can improve vascular health in individuals who are at risk for cardiovascular disease. The results also support the concept that with respect to select indicators of vascular health (e.g. platelet reactivity, endothelial relaxation, etc.), a preliminary testing of the putative beneficial effects of foods and supplements can be of value in the identification of promising foods and food components.