Prior studies have shown that eating dark chocolate may lower blood pressure and improve cholesterol levels—both of which are good for preventing heart disease and strokes. In this meta-analysis—in which data from many studies are combined and analyzed together—researchers reviewed studies exploring the link between dark chocolate consumption and health. Researchers estimated the number of heart attack and strokes that might be prevented through this appealing preventive option. Their review included 2,013 participants, all of whom had metabolic syndrome (symptoms include high blood pressure, large waist circumference, and high fasting sugar (glucose) levels). The chocolate used in the study contained natural plant compounds called polyphenols in an amount equivalent to the amount found in 100 grams of dark chocolate per day for at least 14 days.
Chocolate lovers will be glad to know that the researchers estimated that if people with metabolic syndrome would eat the [prescribed] plain dark chocolate every day, this could potentially prevent 85 cardiovascular events (heart attacks and stroke) per 10,000 people treated over 10 years.
According to the study authors, “Dark chocolate, derived from cocoa beans, is another food rich in polyphenols, specifically flavonoids. Flavonoids exhibit antihypertensive, anti-inflammatory, antithrombotic, and metabolic effects, all of which may contribute to their protective effect.” They caution, however, that this study is an estimation based on available short-term data, and studies have not yet determined the long-term effects of eating dark chocolate every day for ten years.
(BMJ 2012;344:e3657 doi: 10.1136/bmj.e3657)