Dark Chocolate provides improved cardiovascular function and lowered risk for heart disease, according to a report in the Journal of the American College of Nutrition.
Dr. Mary Engler, a professor of physiological nursing at the University of California, San Francisco School of Nursing, says that eating dark chocolate can make arteries expand, increasing blood flow, and thus reducing cardiovascular risk.
Milk chocolate does not provide the same protection, Dr. Engler stresses, because it is, well, too milky. Look for darker chocolates, because darkness is an indicator of high levels of flavonoids, the chemicals that loosen up the arteries.
Flavonoids are naturally-occurring compounds found in plant-based foods. According to the Chocolate Information Center, supported by Mars, Inc., scientists have discovered that one of the functions flavonoids may have is to act as antioxidants in humans.
Antioxidants are believed to help the body's cells resist damage by free radicals, which are formed by numerous processes including when the body's cells utilize oxygen for energy.
Tastes Good, Supports Health
You can tell that a chocolate has a high flavonoid content because "the flavor is so intense and rich," Dr. Engler says.
Dr. Engler and her colleagues asked 11 willing participants to eat 1.6 ounces of flavonoid-rich chocolate every day for two weeks. Another 10 volunteers consumed an equal amount of low-flavonoid chocolate.
Ultrasound measurements showed that expansion of the arteries in response to greater blood flow increased by 10 percent in the flavonoid consumers, while there was a slight decrease in those who got the flavonoid-poor chocolate.
Blood levels of a powerful flavonoid, epicatechin, rose more than eightfold for the high-flavonoid group and remained unchanged for the others.
The study was conducted in collaboration with the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.
Flavonoids Found in a Variety of Foods
Dr. Jeffrey Blumberg, chief of the center's Antioxidant Research Laboratory, said the work has expanded to look at other flavonoid-containing foods.
"Not only chocolate, but also tea, oat bran, almond skins, and blueberries, all are good sources of flavonoids," Dr. Blumberg said. "We're trying to get a better understanding of vital chemicals, flavonoids being one of the larger groups."
Dark chocolate "happens to be a rich source of flavonoids," Dr. Blumberg said, but he adds that "we are not trying to position chocolate as a health food."
In addition to flavonoids, chocolate also has a lot of calories and a lot of saturated fat, neither of which is good for the arteries, he says.
"But in the context of a reasonable diet, chocolate is not only a pleasurable food but might contain some health-promoting ingredients," Dr. Blumberg says.
Recommendations about dark chocolate can be compared with those about wine, Dr. Engler says.
An occasional glass or two of wine has been shown to be associated with a reduced risk of cardiovascular disease, she says, "but people should not be overindulgent with wine. The same is true of dark chocolate in moderation as part of a well-balanced diet."
Always consult your physician for more information.