A new study finds that a cup of blueberries a day can help reduce blood pressure in postmenopausal women. Forty-eight women with pre- and stage 1- hypertension participated in the 8-week study. The participants were randomly placed into one of two groups. The first group received 22 grams of freeze-dried blueberry powder each day, which is the equivalent of 1 cup of blueberries. The other group received 22 grams of a placebo powder. Otherwise, both groups continued their normal diet and exercise routines.
The women had their blood pressure evaluated at the beginning of the study, after 4-weeks of daily blueberry consumption, and again after the 8-week study completion. While no significant improvement was measured after 4-weeks, noteworthy reductions were observed after 8-weeks. The top number that measures the pressure in the arteries when the heart beats, also known as systolic blood pressure, saw a 5.1% average decrease in the first group. In addition, diastolic blood pressure, or the bottom number that measures the pressure in the arteries between heart beats, was reduced by 6.3% on average. There were no changes in the blood pressure of the participants in the placebo group.
Source: Johnson S, Figueroa A, Navaei N, et al. Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial. Journal of the Academy of Nutrition and Dietetics, 2015 March; 115 (3): 369-377.