The phytochemicals that give blueberries their blue color can dramatically improve cardiovascular health, according to a beautiful two-part study.
Nicknamed “the silent killer” because it has no visible symptoms in its early stages, hypertension affects approximately one in three adults. This condition puts a strain on the cardiovascular system which, in the long term, can contribute to heart failure, stroke and kidney failure.
For sufferers hypertension, you should already control your condition by eating a healthy diet, exercising, not smoking and maintaining a healthy weight. But do you need to eat anything in particular to keep your arteries healthy? Yes! Besides broccoli, spinach, pulses and fish, berries may also reduce heart disease, thanks to their antioxidant polyphenols.
A study looked at the cardiovascular effects blueberries and reveals that anthocyanins, the phytochemicals that give blueberries their color, are the mediators of the beneficial effects of this fruit on the cardiovascular system. The lead author of the study is Ana Rodriguez-Mateos, MD, from the Department of Nutritional Sciences at King’s College London, UK. The researchers published their findings in The Journals of Gerontology: Series A.
Anthocyanins and blood pressure
Rodriguez-Mateos and colleagues recruited 29 study participants who were completely healthy and randomly divided them into two groups: One was received a daily drink consisting of 200 grams (g) of blueberries, and the other group received a control drink. To examine the effects of blueberries, the researchers took the participants’ blood pressure and measured the flow-mediated dilation (DFM) of their brachial arteries. FMD is a standard indicator of cardiovascular risk. It measures the widening of the brachial artery when the blood is flowing at a higher rate. In the second part of the study, the researchers compared the consumption of blueberries with the consumption of purified anthocyanins or control beverages with concentrations of fiber, minerals or vitamins equivalent to those of blueberries.
Blood pressure decreases by 5 mm Hg in a month
Scientists noticed the beneficial effects of blueberry drinks only 2 hours after the participants consumed them. Purified anthocyanins dose-dependently improved endothelial function in healthy humans. The endothelium is a type of membrane located inside the heart and blood vessels. It contains endothelial cells that help control the expansion and contraction of the arteries. Endothelial cells also help control blood pressure and play a key role in blood clotting.
The authors explain that the effects were similar to those of blueberries containing similar amounts of anthocyanins, while control beverages containing fiber, minerals or vitamins had no significant effect. After a month of consuming 29g of blueberries per day, the participants’ blood pressure decreased by 5 millimeters of mercury (mm Hg), on average. The researchers note that such a drop is usually achieved with drugs.
These results identify anthocyanin metabolites as major mediators of blueberry vascular bioactivities and changes in cellular genetic programs . The person in charge of the study concludes that although it is preferable to eat the blueberry whole to reap all the benefits, this study shows that the majority of the effects can be explained by the anthocyanins.
Source
Circulating Anthocyanin Metabolites Mediate Vascular Benefits of Blueberries: Insights From Randomized Controlled Trials, Metabolomics, and Nutrigenomics
