Why Doctors think you should eat more Dark Chocolate

by Pam Marcovitz, M.D.

Director, Ministrelli Women’s Heart Center, Beaumont Hospital

Just in time for Valentine’s Day, a new study suggests that eating dark chocolate may have additional benefits above and beyond simply making us feel good. Does that mean that it is all right to open that sinful-looking, heart-shaped box and indulge?

A recent study announced at the American Heart Association‘s Annual Scientific Meeting showed that eating a small amount of dark chocolate each day for two weeks could improve circulation to the heart.

Half of 39 study participants were asked to eat 1.4 ounces of dark chocolate, while the other half consumed a similar amount of white chocolate. Those who ate dark chocolate demonstrated an improved ability to dilate or increase blood vessel size and better blood flow to the heart, while the white chocolate eaters had no change in their heart’s circulation.

The benefits of dark chocolate are believed to derive from the antioxidant benefits found in compounds known as flavenoids, the same substances as in red wine, green and black tea, and in some fruits and vegetables, which are also believed to lower heart disease risk. The greatest benefits are seen in chocolate containing high amounts of cocoa, or cacao polyphenols, which have the highest amounts of flavenoids - about four times as many as in red wine or tea. To find dark chocolate with the greatest amount of flavenoids, look for those with a high percentage of cocoa. Those with about 70 percent cocoa are best at providing these protective antioxidant effects and are identified by their “bittersweet” rather than “sugary” taste. In fact, the more sugar there is in a chocolate bar, the less likely it will provide these health benefits. The more the sugar, the higher the calories, and that negates the beneficial effects of dark chocolate. For this reason, most studies looking at the potential health benefits of chocolate compare dark chocolate to other types of chocolate with less cocoa, such as milk chocolate or white chocolate.

The recent study concerning improved blood flow to the heart is only one of several which demonstrate beneficial effects of dark chocolate on the cardiovascular system. Other research has shown that consuming between one and three ounces of dark chocolate may lower the top number of the blood pressure (systolic) between 5 and 10 points and the bottom number (diastolic) between 2 and 5 points. An overview published last year in the Archives of Internal Medicine looking at the results of several other studies found cocoa to be much more effective at lowering blood pressure than teas, despite the fact that green and black teas contain antioxidant substances.

Research published in the Journal of the American Medical Association showed that cocoa-containing dark chocolate lowered blood pressure and increased a small amount of a substance in the bloodstream that causes arteries to dilate. It appears from other investigations on limited numbers of individuals that chocolate may boost the anti-clotting effects of aspirin, may lower “bad” or LDL cholesterol and the risk of stroke, and increase the body’s sensitivity to insulin possibly helping to prevent diabetes. Some of these effects, especially those of boosting the body’s ability to handle insulin, may seem contrary to what we have been taught about preventing diabetes through avoiding too many sweets and other refined carbohydrates.

Remember, what is key to the proposed beneficial effects in all of these studies is that the portion of chocolate was small – about three small squares of a larger bar – and that the type of chocolate used in all of these studies contained far less sugar than the traditional American mild chocolate candy bar.

Nobody is suggesting that adding additional chocolate to one’s diet above and beyond calories already consumed in a daily diet would be of benefit. In fact, care should be taken not to increase daily calories contained in eating a portion of chocolate. Otherwise the additional calories consumed could balance out the beneficial effects of chocolate in a negative fashion.

Still, it’s nice to know that consuming something that tastes good may not be as harmful to our health as previously thought. As long as excess calories are not being consumed, we do not have to feel guilty for having a small amount of this treat and we even may be reaping some health benefits by substituting an amount of dark chocolate for dessert.

Pamela Marcovitz M.D. is the director of the Ministrelli Women’s Heart Center at Beaumont Hospital, Royal Oak. Opened in 2002, the Ministrelli Women’s Heart Center is the first and only cardiac center in Michigan designed expressly for the prevention, diagnosis and research of women’s heart disease. This state-of-the-art facility features on-site diagnostic capabilities, including stress tests, EKGs and echocardiograms (heart ultrasounds). To receive more information on heart disease or the Ministrelli Women’s Heart Center, please call 248-898-4760.