Is chocolate good for your heart?
Go ahead, eat that chunk of dark chocolate—you may be doing your heart a favor.
That's the upshot of a new study by a group with VA, Brigham and Women's Hospital, and Harvard Medical School. Led by Luc Djoussé, MD, MPH, DSc, the researchers examined chocolate-eating habits and the prevalence of coronary heart disease among nearly 5,000 adults ranging in age from 25 to 93.
Those who reported eating chocolate five times per week or more were about half as likely to have heart disease, compared with those who didn't partake at all. For those who ate less chocolate, up to four servings a week, there was still a 26-percent reduction in heart disease. The researchers adjusted for various factors that could have influenced the results, such as age, smoking, exercise or hereditary heart risk.
The results appeared online in September in the journal Clinical Nutrition.
While the study didn't distinguish among different types of chocolate—dark chocolate versus more sugary types—it did find that eating non-chocolate candy was associated with an increase in heart disease.
Djoussé says dark chocolate is rich in beneficial natural chemicals called flavonoids, which act as antioxidants. The food has been shown in other research to help lower blood pressure, prevent excess blood clotting and lower inflammation. A related study published earlier this year by Djoussé's group found yet further cardiovascular benefits—less atherosclerotic plaque among those who ate more chocolate.
The VA-Harvard researcher notes that the health effects of chocolate are not due solely to its antioxidant properties. He points out that red wine, also an antioxidant, does not lower blood pressure. So there are other chemical factors at play.
Even though the new study results would seem to suggest "the more the better" when it comes to chocolate, Djoussé urges moderation. "At this point, for cardiovascular benefits, moderate consumption of two to three servings per week would be reasonable."
A Harvard colleague of Djoussé's, Murray Mittleman, MD, DrPH, recently led a study of nearly 32,000 Swedish women that also showed a cardiovascular benefit to chocolate—specifically, in cutting the risk of heart failure. He, too, warns against excessive consumption: "You can't ignore that chocolate is a relatively calorie-dense food, and large amounts of habitual consumption are going to raise your risks for weight gain. But if you're going to have a treat, dark chocolate is probably a good choice, as long as it's in moderation."
This article originally appeared in the October-November 2010 issue of VA Research Currents.