Short course: Blueberries may lower blood pressure

Can a cup of blueberries keep the doctor away? Maybe. Researchers conducted a randomised, double-blind, placebo-controlled study of 40 postmenopausal women ages 45 to 65 with high blood pressure. Half ate 22 grams of freeze-dried blueberry powder (equivalent to a cup of blueberries) daily for eight weeks. The others consumed an identical-looking and tasting placebo. The study, in The Journal of the Academy of Nutrition and Dietetics, found that those who ate the blueberry preparation saw an average 5.1 percent decrease in systolic blood pressure (the top number) and a 6.3 per cent decrease in diastolic pressure. Levels of nitric oxide, known to be involved in relaxing and widening blood vessels, increased significantly in the blueberry eaters. There were no significant changes in the placebo group. The improvement, the scientists write, was moderate compared with that of blood pressure medicines. But, they say, eating blueberries in larger amounts or for longer periods could increase the effect.