Blueberries may be good for the heart.
Researchers conducted a randomized, double-blinded trial with 115 overweight and obese adults aged 50 to 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 final third 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 percent and the risk of coronary heart disease by 11.4 to 14.5 percent.
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. “If everyone ate more fruits and berries rich in anthocyanin,” she said, “there would be significant individual and population health benefits.”
The study received support from the U.S. Highbush Blueberry Council.