The power of blueberries to improve hypertension
A new study on post-menopausal women published in the Journal of the Academy of Nutrition and Dietetics (2015, doi: 10.1016/j.jand.2014.11.001) reports that just one cup of blueberries per day could reduce blood pressure and arterial stiffness, which are risk factors for cardiovascular disease. The study reported that the blueberries also produced a remarkable increase in nitric oxide levels, a blood biomarker which acts a vasodilator.
“Our findings suggest that regular consumption of blueberries could potentially delay the progression of prehypertension to hypertension, therefore reducing cardiovascular disease risk,” said the research team.
Over an eight-week period, researchers randomly assigned 48 postmenopausal women with pre- and stage-1 hypertension to receive either 22 grams of freeze-dried blueberry powder -the equivalent to one cup of fresh blueberries – or 22 grams of a placebo powder. At the end of the eight weeks, participants receiving the blueberry powder on average had a 7 mmHg (5.1%) decrease in systolic blood pressure, the higher number in the blood pressure reading that measures the pressure in the arteries when the heart beats. They also saw a 5 mmHg (6.3%) reduction in diastolic blood pressure, or the lower number measuring the pressure in the arteries between heartbeats. The blueberry-treated group also had an average reduction of 97 cm/second (6.5%) in arterial stiffness.
They also found that nitric oxide increased by a staggering 68.5%. That is important, the researchers added, because arterial stiffness and the narrowing of blood vessels are both a part of hypertension. This rise in nitric oxide helps explain the reductions in blood pressure.
This study is particularly interesting because the amount of blueberries necessary to achieve these improvements in blood pressure and arterial stiffness, just one cup, is very achievable for most people.
Previous studies on blueberries have shown positive effects on cardiovascular risk factors including blood pressure, but they all included large amounts of blueberry powder consumption, anywhere from 50 grams to 250 grams. In the case of 250 grams, that would translate to more than 11 cups of fresh blueberries, which are far less realistic as a daily intake.
Blueberries can be eaten on their own as a snack, added to your breakfast yogurt, or tossed into your smoothies quite easily.
For more research-based information on how to improve your blood pressure, click here.