Sept. 25, 2008 -- A piece of dark chocolate a day -- a very small piece -- keeps the doctor away.

An Italian study shows that dark chocolate can significantly reduce the inflammation that leads to cardiovascular disease. The ideal amount is 6.7 grams per day (0.23 ounces). A typical Hershey chocolate bar weighs about 43 grams. That means eating one dark chocolate bar over the course of 6 1/2 days to get 6.7 grams per day.

Milk chocolate doesn't appear to offer the same benefits.

The study was conducted by Research Laboratories of the Catholic University in Campobasso and the National Cancer Institute of Milan and has been published in the Journal of Nutrition. The data come from an epidemiological study called the Moli-sani Project, which selected men and women at least 35 years old randomly from city hall registries in southern Italy.

For the chocolate study, researchers identified 4,849 people in good health without risk factors for cardiovascular disease, such as high cholesterol and high blood pressure. These participants were asked about their dark chocolate consumption.

Chronic inflammation can lead to heart disease, so keeping inflammation under control is a major part of preventive treatment. Research has shown that patients who have a low amount of C-reactive protein in their blood have lower levels of inflammation. People who eat dark chocolate regularly, in small servings, have significantly lower levels of C reactive protein, according to the study. This holds true even after accounting for any other potential confounding factors (such as differences in other dietary practices).