Dark chocolate good for the heart: Study

By Dr. Ananya Mandal, MDApr 25 2012

A new study finds that dark chocolate may lower the risk of heart disease by lowering levels of blood glucose and bad cholesterol while boosting levels of good cholesterol.

The study finds that chocolate contains compounds called flavanols (sometimes referred to as Flavan-3-ols, a class of flavonoids), which have antioxidant and anti-inflammatory properties. Previous research has shown a link between flavanol intake and risk for cardiovascular disease. Flavonoids are compounds produced by plants that function as important pigment molecules. They’ve gained popularity as the substance responsible for the cardioprotective effects of red wine. Anti-microbial, anti-cancer, and cardio-protective effects have also been attributed to this special substance.

For the study the researchers at San Diego State University assigned 31 people to consume 50 grams per day of either dark chocolate (70 percent cocoa) or white chocolate (0 percent cocoa). Dark chocolate was used because it has higher flavanol levels than milk chocolate. The participants' blood pressure, forearm skin blood flow, circulating lipid (fat) profiles and blood glucose levels were recorded before and after they consumed the chocolate for 15 days.

Results showed that those who ate dark chocolate had lower levels of blood glucose and bad low-density lipoprotein (LDL) cholesterol, and higher levels of good high-density lipoprotein (HDL) cholesterol than those who ate white chocolate.

Despite these and other findings that dark chocolate may reduce the risk of cardiovascular disease, the researchers said chocolate must be eaten in moderation because of its saturated fat and caloric content. It's estimated that the typical American consumes more than 10 pounds of chocolate a year.

“Compliance with our study subjects were great because everybody wanted to eat chocolate,” the researchers said. “We actually had to tell them not to eat more than 50 grams a day.” Along with flavonoids, 50 grams of dark chocolate has about 252 calories — and half of those calories are from fat.  To put this in perspective, a single chocolate chip gives you enough calories to provide energy to walk about 150 feet.

The study is scheduled to be presented today at the Experimental Biology 2012 meeting in San Diego.