Q: Dark chocolate is supposed to be good for the heart. But how do I know which chocolate is “dark?” Some labels list the percent dark chocolate, others percent cocoa solids. Can you help me pick the best one?
A:Chocolate makers are promoting dark chocolates to cash in on two different trends. One is a growing demand for “gourmet” chocolates, described in mouthwatering detail by food writer Bill Buford in his essay “Extreme Chocolate,” in the Oct. 29 New Yorker. The other trend has to do with the growing perception that chocolate improves blood flow through arteries nourishing the heart, brain and other parts of the body.
Chocolate’s artery-opening activity is attributed to compounds called flavanols that are abundant in cacao beans, as well as in onions, apples, berries, beans and some types of tea.
Just because cacao beans contain flavanols doesn’t mean that chocolate does. In fact, the bitter-tasting flavanols are traditionally removed. “Dutched” cocoa, which has been treated with alkali, has few active flavanols.
You can’t tell the flavanol content from the color of a chocolate bar or the percent cocoa it contains. “Specifically, what the world needs is a label on each package that describes the flavanol content of the chocolate,” writes Dr. Norman K. Hollenberg, a Harvard University professor who has been studying the physiologic effects of chocolate since the mid-1990s, in an article in Circulation.
Until that happens, look for the least-processed chocolate you can find. Skip those that have been treated with alkali. And keep in mind that you don’t need much. Studies showing the benefits of cocoa have used an ounce — sometimes less — of flavanol-rich chocolate. The tough part of this dietary “therapy” is stopping with a small piece. But stop you should. An ounce of dark chocolate delivers about 150 calories. Eat that much every day without cutting back elsewhere and the girth you gain would far outweigh any benefit from chocolate.
Dr. Thomas Lee, editor in chief, Harvard Heart Letter
