Abstract
OBJECTIVES: The aim of this study is to investigate the effect of chronic strawberry intake on cardiovascular risk factors including fasting lipids concentrations, vascular endothelial function and blood pressure in middle-age overweight or obese individuals with moderate hypercholesterolemia. We hypothesized that 4-week strawberry intake would improve the lipids profile and concomitantly improve measures of vascular function. METHODS: In this randomized, double-blinded, controlled, crossover trial, thirty-four subjects (age 53 ± 1 years, BMI 31 ± 1 kg m-2, mean ± SD) consumed a strawberry beverage containing 25 gram freeze-dried strawberry powder or energy-matched control beverage in random order twice a day for 4 weeks. Treatment periods were separated by 4-week washout period. Fasting lipids, glucose, insulin, high sensitive c-reactive protein (hs-CRP), and postprandial flow-mediated dilation (FMD) and blood pressure, were measured at weeks 0, 4, 8 and 12. RESULTS: Fasting lipids, glucose, insulin, and hs-CRP did not differ between strawberry and control beverage interventions. In contrast, vascular function as measured by change in %FMD was significantly increased after strawberry compared to control after 4 weeks supplementation (4.3 ± 0.3% versus 3.6 ± 0.3%, respectively, p = 0.0096). In addition, %FMD was acutely increased from 0 to 1 hour after consuming strawberry beverage (p < 0.0001), which was consistent with reduced meal-induced increases in systolic blood pressure (SBP) postmeal (mean 2 hour changes in SBP after strawberry compared to control beverage, 2.3 ± 0.4 versus 3.4 ± 0.4 mmHg, p = 0.048). CONCLUSIONS: Daily intake of strawberries may improve endothelial function and acute changes in blood pressure, independent of other metabolic changes, and may be considered a specific food/fruit to include in a heart-healthy diet in overweight or obese subjects with moderate hypercholesterolemia. FUNDING SOURCES: California Strawberry Commission, Watsonville, CA, USA. SUPPORTING TABLES, IMAGES AND/OR GRAPHS: