Flavonoid-rich beverage effects on lipid profile and blood pressure in diabetic patients

To compare freeze-dried strawberry (FDS) beverage and strawberry-flavored drink effects on lipid profile and blood pressure in type 2 diabetic (T2D) patients.

In a randomized, double-blind, controlled trial, 36 subjects with T2D (23 females; mean ± SE age: 51.57 ± 10 years) were randomly divided into two groups. Participants consumed two cups of either pure FDS beverage (each cup containing 25 g freeze-dried strawberry powder equivalent to one serving of fresh strawberries; intervention group) or an iso-caloric drink with strawberry flavoring (similar to the FDS drink in fiber content and color; placebo group) daily for 6 wk. Anthropometric measurements, 3 d, 24 h dietary recall, and fasting blood samples were collected at baseline and at weeks 6 intervention. After lying down and relaxing for approximately 10 min, each participant's blood pressure was recorded in triplicate with 5 min intervals; recordings were made at baseline and the trial end-point. Each participant's lipid profile was assessed before and after intervention.

Assessment at the weeks 6 intervention showed a significant reduction from baseline in total cholesterol levels and total cholesterol to high-density lipoprotein cholesterol (HDL-C) ratio in the intervention group (179.01 ± 31.86 to 165.9 ± 32.4 mg/L; P = 0.00 and 3.9 ± 0.88 to 3.6 ± 0.082 mg/L; P = 0.00 respectively), but the change was not significantly different between the two groups (P = 0.07, P = 0.29 respectively). Systolic blood pressure levels were significantly reduced from baseline in both the FDS and placebo drink groups (129.95 ± 14.9 to 114.3 ± 27.5 mmHg; P = 0.02 and 127.6 ± 15.6 to 122.9 ± 14.47 mmHg; P = 0.00 respectively), but the reduction was not significantly different between the two groups. Diastolic blood pressure was significantly reduced post-intervention in the FDS drink group compared to placebo group (78.7 ± 7.2 vs 84.4 ± 5.8; P = 0.01), the reduction was also significant within the FDS drink group (84.2 ± 8.03 to 78.7 ± 7.2; P = 0.00). Triglycerides, HDL-C concentrations and anthropometric indices showed no significant differences between or within groups.

Short-term FDS supplementation improved selected cardiovascular risk factors in subjects with T2D. Long-term effects on other metabolic biomarkers need to be investigated in future trials.