Compound in Cocoa Improves Blood Vessel Response to Stress

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Compound in Cocoa Improves Blood Vessel Response to Stress

Consuming flavanols — a group of antioxidant compounds found in cocoa — reduced the harmful effect of stress on blood vessel function in healthy young adults, in a new study published in the journal Nutrients.

As the study authors note, mental stress has been shown to be linked to cardiovascular events (like stroke and heart attack), most likely due to its harmful effect on the function of blood vessels (vascular function). Past studies have shown that flavanols from cocoa improve the function of the endothelium, a thin membrane that lines the insides of blood vessels. Problems with the endothelium — including inflammation — can set the stage for serious health problems, including the buildup of plaque in arteries, which can lead to a range of cardiovascular problems.

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For the latest study, 30 young, healthy men consumed a cocoa-based beverage containing flavanols. Each was randomly assigned to drink either a high-flavanol beverage, containing 150 milligrams of flavanols, or a low-flavanol beverage containing less than 4 milligrams. This took place 90 minutes before participants were given an 8-minute mentally stressful task. The researchers took a variety of measurements both before and after drinking the beverage, both at rest and during stress. These measurements included forearm blood flow, blood pressure, and cardiovascular activity. Endothelial function and blood pressure were also assessed before drinking the beverage and again 30 minutes and 90 minutes after the stressful task.

Flavonols found to improve several cardiovascular markers

In all participants, endothelial function (as measured by a test called brachial flow-mediated dilation) was impaired 30 minutes following stress, but this effect was smaller in participants who had consumed the high-flavanol beverage. After 90 minutes, endothelial function was still significantly better in this group than in participants who drank the low-flavanol beverage. The high-flavanol beverage was also found to increase forearm blood flow both at rest and during stress. There was no significant difference in cardiovascular or blood pressure responses to stress between the high- and low-flavanol beverage groups.

“Flavanols are effective at counteracting mental stress-induced endothelial dysfunction and improving…blood flow during stress,” the researchers concluded. “These findings suggest the use of flavanol-rich dietary strategies to protect vascular health during stress.”

As noted in an article on the study at Medical Dialogues, cocoa isn’t the only food ingredient rich in flavanols, which are also found in a variety of fruits and vegetables including apples, pears, dark grapes, blackberries, cherries, raspberries, green tea, and pulses (beans, peas, and lentils). Consuming a variety of these foods, in addition to unprocessed cocoa, could help people achieve a daily intake of flavanols similar to the amount seen in the high-flavanol beverage in the study.

Want to learn more about protecting your heart? Read “Be Heart Smart: Know Your Numbers,” “Does Diabetes Hurt Your Heart?” “Fight Off Heart Disease With These Five Heart-Healthy Foods” and “Lower Your Risk of Heart Disease.”

Living with type 2 diabetes? Check out our free type 2 e-course!

Quinn Phillips

Quinn Phillips

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A freelance health writer and editor based in Wisconsin, Phillips has a degree from Harvard University. He is a former Editorial Assistant for Diabetes Self-Management and has years of experience covering diabetes and related health conditions. Phillips writes on a variety of topics, but is especially interested in the intersection of health and public policy.

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