Chocolate to cure a broken heart is a popular prescription, but it turns out chocolate’s heart-mending reputation might just be deserved. A few months ago, Harvard researchers reported that in a study of over 31,000 middle-aged and elderly Swedish women, those who consumed one or two ounces of chocolate a week had a 32 percent lower risk of heart failure than women who ate no chocolate. Similar large-scale studies have suggested that people who regularly eat moderate amounts of chocolate may have lower incidence of high blood pressure, hardened arteries and even strokes.
Researchers aren’t sure exactly how chocolate helps the heart, but a likely explanation is that compounds in cocoa called flavanols help activate enzymes that release nitric oxide—a substance that helps widen and relax blood vessels. That allows blood to flow through the vessels more freely, reducing blood pressure. Nitric oxide is also involved in thinning blood and reducing its tendency to clot—lowering, potentially, the risk of stroke.
What’s more, some of the key flavanols in cocoa, catechins and epicatechins (also found in red wine and green tea) are known to have heart-healthy, antioxidant effects—such as helping to prevent artery-threatening LDL cholesterol from converting to a more lethal, oxidized form. (While cocoa butter, the fatty part of chocolate, contains some saturated fat, it’s mostly stearic acid, a more benign sat-fat that doesn’t appear to raise LDL levels.) Cocoa flavonols also have anti-inflammatory properties that could protect the heart and arteries, and thus might someday have a role in managing other diseases associated with inflammation and blood vessel damage, such as diabetes and Alzheimer’s disease.