By David Blyweiss, M.D. Advanced Natural Wellness
I have a confession to make. I love a good piece of dark chocolate. To some, that might seem like a weakness. But, new evidence suggests that it might be a virtue—at least as far as my cardiovascular system is concerned.
A few months ago, Canadian scientists discovered that eating chocolate regularly significantly reduces the odds of having a stroke. Now other researchers are providing even more evidence that chocolate—especially the dark variety—benefits the entire cardiovascular system. In fact, eating just one small square of chocolate a day can lower your blood pressure and reduce your risk of heart disease.
Researchers at the German Institute of Human Nutrition in Nuthetal, Germany, reached this conclusion after following 19,357 people between the ages of 35 and 65 for at least ten years. During that time, they kept track of the participants’ chocolate consumption. The results? The research subjects who ate the most chocolate (on average, about a quarter of an ounce a day) had lower blood pressure. What’s more, the risk of the chocolate lovers having a heart attack or stroke was 39 percent lower than those with the lowest chocolate intake.
So what is it about chocolate that has such as profound impact on cardiovascular health? At first glance, chocolate’s documented ability to lower blood pressure would appear to be the key. And, in fact, the scientists found that lowered blood pressure due to chocolate consumption at the start of the study explained about 12 percent of the reduced risk of heart attacks and strokes. But they think something else is going on in the bodies of regular chocolate eaters that accounts for the enormous drop in their heart attack risk.
One possibility is that the phytochemicals known as flavanols that are abundant in cocoa somehow protect the cardiovascular system. Because dark chocolate contains more cocoa—and, therefore, more flavanols—it may have more health benefits than other varieties of chocolate. Flavanols are responsible for improving the bioavailability of nitric oxide from the cells that line the inner wall of blood vessels (vascular endothelial cells). Nitric oxide is a gas that, once released, causes the smooth muscle cells of the blood vessels to relax and widen. Nitric oxide also improves platelet function, making the blood less sticky and the vascular endothelium less attractive to white blood cells. This effect was shown in a clinical trial which was published in the Journal of the American Medical Association in 2007.
The effects of dark chocolate also linger in the body. The highest blood concentrations of flavanols from chocolate are obtained two to three hours after eating it. And the flavonols are still measurable after eight hours. How much antioxidant power do those flavonols deliver? Studies show that cocoa powder, dark chocolate and milk chocolate have higher Oxygen Radical Absorption Capacity (ORAC) values than many common foods, such as prunes and blueberries. Dark chocolate has more than 13,000 ORAC units and you can double that amount for unsweetened cocoa powder.
Of course, like all good things, there are caveats. Much of the commercial chocolate produced in the U.S. is made with large amounts of refined sugar and often contains artificial flavorings and other non-healthy ingredients. It’s also loaded with calories. A three-and-a-half ounce chocolate bar contains roughly 500 calories. Instead, consider adding small amounts—one ounce or less—of chocolate that contains at least 70 percent cacao to your diet each day. This amount has been shown to reduce oxidative stress and improve vascular and platelet function. Savoring a small piece or two of high quality dark chocolate after dinner is a tasty way to boost your polyphenol levels. It’s one sweet treat that your heart will love!
Buijsse B. Chocolate consumption in relation to blood pressure and risk of cardiovascular disease in German adults. European Heart Journal. 2010 Mar 30. [Epub ahead of print]
Marcus MB. Analysis: Chocolate may reduce stroke risk. USA Today. 12 Feb 2010.
Taubert D. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. Journal of the American Medical Association. 2007;298:49-60.