Bittersweet Victory for Chocolate: Study Confirms Health Benefits

July 19, 2005 — -- Willie Wonka fans have more to celebrate this week -- even more evidence chocolate is good for the heart.

A study published by the journal Hypertension on Monday adds to the growing body of evidence showing the health benefits of everyone's favorite sweet treat. The heart-healthy effects come from chemicals called flavonoids that are found in cocoa powder.

"Flavonoids are antioxidants that reduce blood pressure by relaxing blood vessels," said Dr. Nieca Goldberg, the chief of Women's Cardiac Care at Lenox Hill Hospital in New York. "Flexible blood vessels are resistant to cholesterol buildup in the arteries."

The new study focused on 20 people with untreated hypertension, half of whom ate a bar of dark chocolate every day for two weeks. The other half ate white chocolate, which doesn't contain flavonoids.

The small size of the experiment made some experts cautious of jumping to conclusions, however. "The study is interesting," said Goldberg, "but [it's] not enough for me to start writing prescriptions for chocolate."

Nevertheless, the effects seen in the group of dark chocolate eaters were significant. Those who ate a bar of chocolate every day had a drop in blood pressure, an increase in blood flow, and were more sensitive to insulin, a hormone that regulates sugar in the body.

"The blood pressure-lowering effect of dark chocolate in this study compares favorably with the one achieves with commonly used anti-hypertensive drugs," said Dr. Frank Messerli, director of the Hypertension Program at St. Luke's-Roosevelt Hospital in New York.

But not just any old bar of chocolate will do. To get those flavonoids, the chocolate needs to have a lot of cocoa powder in it. In other words, it needs to be dark chocolate. It's the flavonoids, in part, that give dark chocolate its bitter taste.

Most commercial chocolate has had its cocoa content diluted with fats and sugars to make it sweeter. The way that chocolate is processed also tends to squeeze out the flavonoids. "Once the refining process gets going, the flavonoids start dropping like flies," said dietician Keith Ayoob of the Albert Einstein College of Medicine in New York.