That's the finding of a small study by Swiss researchers published in the journal Heart.
The researchers gave 20 male smokers approximately 1.4 ounces of either dark or white chocolate. In just two hours, dark chocolate significantly improved the function of endothelial cells, which line the artery walls, and reduced the activity of platelets, which help form blood clots. Smoking is known to disrupt the function of both types of cells, often leading to hardening of the arteries and heart disease.
The protective effects of dark chocolate lasted about eight hours. White chocolate had no effect on the arteries or platelets. The study did not examine the effects of chocolate in nonsmokers.
'A Small Daily Treat'
The researchers note that too much chocolate could increase the risk of heart disease by raising blood sugar levels, body fat, and body weight. But their findings suggest just a couple ounces of dark chocolate a day may reduce the risk of coronary artery disease.
How could such a small amount have such a powerful effect? The authors say it's probably because dark chocolate is so rich in antioxidants. "Dark chocolate has a much higher [antioxidant] content per gram than do other antioxidant-rich foods such as wine, tea, or berries," they write. "Therefore, only a small daily treat of dark chocolate may substantially increase the amount of antioxidant intake" and improve cardiovascular health.
SOURCES: Hermann, F. Heart. January 2006; vol. 92: 119–120. News release, BMJ Specialist Journals.
By Sherry Rauh
Reviewed by Louise Chang, MD
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