The Journal of the Academy of Nutrition and Dietetics recently published the results of a study in post-menopausal women with early hypertension. The study provided daily blueberry powder to half the women and after 8 weeks, those receiving the blueberry powder had a statistically significant decrease in blood pressure. For systolic pressure (the top number) it was 7 mm of mercury lower and for the diastolic (bottom number) it was 5. They also measured nitric oxide levels in the patient’s blood. Nitric oxide, which helps dilate (widen by relaxing) artery walls, was also elevated (good response) which could explain the lowering of blood pressure.
Since we are talking about blood pressure, I will remind us that we should always take research studies with a grain of salt (pun intended). Researchers attempt to factor out all the possible ways that their comparison could be biased or skewed. This is impossible in reality, but they do their best. One helpful thing about this study is that they looking at both a clinical measurement (blood pressure) and a chemical measurement (nitric oxide) which would explain the former. Since both improved together, that does lend some strength to the paper’s conclusion of blueberries lowering blood pressure.
What does this mean for you?
Does this mean everyone can throw away their blood pressure medications and eat 5 pounds of blueberries a day? No. First, this only studied women after menopause with borderline blood pressure. If you are not in that group, you are even less sure of its impact on you. Beside, this is just one study. Don’t bet the house on one study. Finally, if your baseline blood pressure without medications is 150 or more, daily blueberries would not bring it below 140 in this study (cut-off for high blood pressure). So, keep taking your medications, but consider more blueberries.
A final comment: I believe more research will lead us to better recognize the importance of a healthy diet on our chronic disease epidemic. Common sense tells us that better nutrition should lead to better health. Often the simple foods of the world bring the most benefit. It seems that maybe they were “designed” that way?