An Experimental Study of a Mediterranean-style Diet Supplemented with Nuts and Extra-virgin Olive Oil for Cardiovascular Disease Risk Reduction: The Healthy Hearts Program (P12-021-19)

Abstract

ObjectivesThe primary objective of this 12-week, randomized, controlled trial was to assess the efficacy of a Mediterranean diet (MD) intervention in reducing cardiovascular disease (CVD) risk factors in a high-risk population in the southeastern United States. MethodsAdults (n = 30) with a BMI of > 24.9 and at least two additional CVD risk factors were randomized into one of two groups. The control group (n = 14) received nutrition education on the recommendations of the American Heart Association (AHA). The intervention group (n = 16) received education promoting patterns of a MD as well as dietary supplements of extra-virgin olive oil (EVOO) and mixed nuts. The primary outcome measure was change in systolic blood pressure from baseline to 6 and 12-weeks. Secondary outcome measures include changes in diastolic blood pressure; weight; BMI; fasted total cholesterol, HDLc, LDLc, TG, total cholesterol to HDLc ratio, blood glucose, and HOMA-IR. Nutrition knowledge and MD adherence were assessed at baseline, 6 and 12-weeks. ResultsThe AHA group had decreases in HDLc, total cholesterol to HDLc ratio, and TG at baseline to 6-weeks, while the MD group had decreases in fat mass and BMR. The total population, experienced a decrease in weight, BMI, and TG from baseline to 6-weeks. At 12-weeks, decreases in weight, BMI, and % body fat were seen in the entire population compared to baseline. The MD group experienced trends towards significance in the differences in measures from baseline to 12-weeks in systolic blood pressure, TG, and total cholesterol to HDLc ratio. Group assignment played a significant role from baseline to 6-weeks in systolic blood pressure, HDLc, and LDLc levels. Nutrition knowledge influenced blood glucose and total cholesterol levels. MD adherence impacted total cholesterol and non-HDLc levels. Percent nut consumption had a significant impact on HDLc levels, % EVOO consumption significantly influenced LDLc values, and the nut/EVOO interaction was significant in both systolic pressure and HDLc levels. ConclusionsIncreases in nutrition knowledge, MD adherence, and % nut and EVOO consumption were the most significant influences on measurement outcomes. Our results suggest that a MD can be implemented on a larger scale with potential positive impacts on CVD risk. Funding SourcesFunding was provided by Mallon-Zallen Graduate Research Fellowship.