Blueberries may be good for the heart.
Researchers conducted a randomized, double-blinded trial with 115 overweight and obese adults ages 50-75 who were at high risk for cardiovascular disease. One-third of the group ate a cup of freeze-dried blueberries a day, another third a half-cup, and the rest a similar-looking placebo. The study, published in the American Journal of Clinical Nutrition, lasted six months.
The diet did not affect insulin resistance or blood pressure. But compared with the half-cup consumers and the placebo group, the full-cup group had reduced arterial stiffness and increased levels of HDL (the “good” cholesterol). Those eating lots of blueberries also had increased levels of anthocyanin, a type of antioxidant found in plant pigments, and increased levels of cyclic guanosine monophosphate, a substance that relaxes smooth muscle cells and improves blood flow.
The authors estimate that eating a cup of blueberries a day reduced the risk of any cardiovascular event by 13% and the risk of coronary heart disease by 11.4% to 14.5%.
The senior author, Aedin Cassidy, a professor of nutrition at the University of East Anglia, said that in a healthier population, as little as three cups of blueberries a week would have beneficial effects.
The study received support from the U.S. Highbush Blueberry Council.
New York Times