Cardioprotective Effects of Freeze Dried Grape Powder Supplementation on Blood Pressure and Plasma Lipids/Lipoproteins: A Pilot Study

Whole food-based dietary interventions have the potential to promote cardiometabolic health via multiple mechanisms, including improvements in blood pressure, bad cholesterol, and other markers of metabolic health. Previous research suggests that grapes have the potential to promote optimal cardiometabolic function by reducing LDL-C, but it remains unclear whether there is a dose-response relationship. Moreover, few studies have evaluated effects on vascular health following daily grape consumption. We propose to examine the effects of 6-8 weeks of supplementation with freeze dried grape powder (69 g/d; ~three ¾ cup servings) compared to a control powder without grapes on: 1) bad cholesterol and blood pressure and 2) other measures of cardiometabolic health, including glucose and insulin. We will enroll overweight (BMI 25-36 kg/m2) but otherwise healthy adults with moderately elevated LDL-C (>115 mg/dL for women and >130 mg/dL for men) and/or blood pressure of120-159/80-99 mm Hg. This will optimize the potential for observing significant changes in these measures of health. We will recruit 20 eligible participants with the expectation that at least 15 will complete the study. The placebo-controlled, crossover study design will allow for a direct comparison of effects within the same participant. We anticipate that the bioactive components of grapes will promote cardiometabolic health via changes in LDL-C and blood pressure. Results from the proposed study would help to clarify how daily grape consumption might promote health and would provide further support for incorporating whole, unprocessed fruit in a healthy dietary pattern.