If you still think of blueberries as an occasional summer treat, think again. Research confirms that eating just a cup a day helps fend off heart disease and cancer.
In a new study from Florida State University, researchers found that a daily serving of blueberries could be key to fighting cardiovascular disease.
They conducted a double-blind, placebo-controlled clinical trial with 48 post-menopausal women with pre-hypertension or stage one hypertension. Every day half the women were given either a placebo or 22 grams of freeze-dried blueberry powder. The powder was equivalent to one cup of fresh blueberries.
During the trial researchers evaluated the women’s blood pressure, as well as their levels of nitric oxide.
They also measured arterial stiffness using brachial ankle pulse wave velocity (PWV), considered the gold standard in evaluating arterial damage. Arterial stiffness is a symptom of atherosclerosis and is predictive of cardiovascular risk. It indicates that the heart has to work harder to circulate blood to the peripheral blood vessels.
The study results were published in the Journal of the Academy of Nutrition and Dietetics. After just 8 weeks the women who took the blueberry powder had significantly lowered their systolic (5.1%) and diastolic (6.3%) blood pressure. Those on the placebo had no change.
In addition, women taking the blueberry powder reduced their arterial stiffness on average by 6.5%. No change was seen in the placebo group.
The researchers attributed the beneficial effects to an amazing 68.5% increase in blood levels of nitric oxide in the women who took the blueberry powder. Nitric oxide is known to widen blood vessels to increase blood flow and lower blood pressure. Those on the placebo had no changes in nitric oxide levels.
The authors noted that their results were “of clinical significance because they demonstrate that blood pressure can be favorably altered by the addition of a single dietary component (eg, blueberries).”
They went on to suggest that “daily blueberry consumption may be effective in preventing the progression of pre-hypertension to hypertension in postmenopausal women.”
Many berries contain polyphenols that have been proven to improve blood pressure, endothelial function, and arterial stiffness. But blueberries are one of the richest sources of polyphenols, including flavonoids, phenolic acids, and stilbenes, which are powerful antioxidants.
Prior research showed that wild blueberries improve endothelial function.