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
Relationships between Vascular Endothelial Function and Physical Activity/Diastolic Blood Pressure in Male University Students