High-quality chocolate may lower the risk of heart failure in middle-aged and older women when eaten once or twice a week — but not when eaten more than that. That's the conclusion of a study published online, Aug. 16, 2010, in Circulation: Heart Failure. Cocoa beans are rich in flavonoids — plant chemicals known to lower blood pressure and improve cholesterol levels and coronary artery function. Cocoa and dark chocolate are already associated with a reduced risk for heart attacks, strokes, and death from heart disease.
The study. Researchers at Harvard Medical School and Sweden's Karolinska Institute followed 31,823 Swedish women ages 48 to 83 for nine years, tracking their chocolate intake with food questionnaires completed as part of the Swedish Mammography Cohort study. At the start of the study, none of the women had a history of diabetes, heart failure, or heart attack. According to the authors, most chocolate then consumed in Sweden had 30% cocoa solids — more than is typically found in chocolate in the United States. The average serving size ranged from 20 to 30 grams (about three-quarters to one full ounce).
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