Fortuitous fruit findings: Blueberries lower blood pressure

Mix, mash or munch. You choose. A study published online Jan. 7 gave blueberries a thumbs up for reducing hypertension in postmenopausal women.

Sarah A, Johnson, PhD, RD, CSO, assistant director at the Center for Advancing Exercise and Nutrition Research on Aging at Florida State University in Tallahassee, and colleagues designed a double-blind, placebo-controlled randomized trial to evaluate whether daily consumption of blueberries reduced blood pressure. They hypothesized the health benefits of the fruit would reduce arterial stiffening and improve endothelial function.

The study randomized postmenopausal participants with pre- and stage 1 hypertension to take the freeze dried equivalent of a cup of fresh blueberries (25 women) or a placebo powder (20 women) for eight weeks. There were no changes in either groups’ blood pressure readings at four weeks.

But at eight weeks, they found a 5.1 percent reduction in mean systolic blood pressure and a 6.3 percent reduction in mean diastolic blood pressure in the blueberry group and no changes in the control group. Compared with baseline, the blueberry group’s brachial-ankle pulse wave velocity dropped and nitric oxide levels increased after eight weeks but the control group’s measures did not change.  

“It is important to note that the findings of this study do not suggest that the effectiveness of the dose of blueberry powder used in this study matches that of antihypertensive medications,” Johnson et al emphasized. They pointed out that the mean systolic blood pressure stayed in the prehypertensive range in the blueberry group at eight weeks. Longer duration of treatment or higher doses of the blueberry powder may have brought the participants into a normal range, they proposed.

The study, which appeared in the Journal of the Academy of Nutrition and Dietetics, was funded by the U.S. Highbush Blueberry Council and the U.S. Agriculture Department.