Published online Dec 15, 2014. doi: 10.4239/wjd.v5.i6.962
Revised: July 30, 2014
Accepted: September 11, 2014
Published online: December 15, 2014
AIM: To compare freeze-dried strawberry (FDS) beverage and strawberry-flavored drink effects on lipid profile and blood pressure in type 2 diabetic (T2D) patients.
METHODS: 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.
RESULTS: 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.
CONCLUSION: 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.
Core tip: Cardiovascular complications are the main cause of mortality in diabetes patients. Considering the role of flavonoids in modulating the latter complications, this study was designed to test the favorable impact of freeze-dried strawberry (FDS) drink, a flavonoid-rich beverage, on the metabolic profile of diabetes patients in a randomized, double-blind, placebo control trial. Lipid profile and blood pressure were improved in patients who consumed the FDS drink for 6 wk. Effects of the latter intervention on other atherosclerotic biomarkers have been discussed separately in Ann Nutr Metab 2013; 63: 256-264. This paper describes the further analysis of other metabolic biomarkers.