Lower Blood Pressure with Blueberries

Postmenopausal women have a high prevalence of hypertension (high blood pressure), and often develop arterial stiffness – a major risk factor for cardiovascular disease. Sarah A. Johnson, from, Florida State University (Florida, USA), and colleagues enrolled 48 postmenopausal women, with pre- and stage 1-hypertension, to receive either 22 g rams of freeze-dried blueberry powder or 22 grams of a control powder, to consume for eight weeks.  Blueberries are one of the richest sources of phenolic compounds, including flavonoids, phenolic acids, and stilbenes, which are known to have biological activity and high antioxidant capacity.  At the end of the study period, mean systolic blood pressure was lower by 5.1% and mean diastolic blood pressure was lower by 6.3% in the subjects in the blueberry group, with no corresponding lowering in the placebo group. In addition, nitric oxide – involved in endothelial vasodilation – was significantly increased in the blueberry group, rising from 9.11 to 15.35 microMoles, with no change in the control group.  The study authors report that: “Daily blueberry consumption may reduce blood pressure and arterial stiffness, which may be due, in part, to increased nitric oxide production.”