Women who eat at least two chocolate bars weekly appear to have a 20 per cent lower risk of stroke, compared to females of the same age and weight who rarely or never eat chocolate, according to a new study.

The study is published in the Journal of the American College of Cardiology.

“Even consuming a relatively small amount of chocolate had quite a large impact on stroke risk, said Susanna Larsson, an associate professor in the division of Nutritional Epidemiology at the Karolinska Institute in Stockholm, who led the investigation

Cocoa contains flavonoids, which have antioxidant properties and can suppress oxidation of low-density lipoprotein, which can cause cardiovascular disease, said Larsson.

Larsson said the benefit appeared proportional to the amount of chocolate in the women's diets. Subjects who ate about two bars of antioxidant-rich Swedish milk chocolate every week had a significantly reduced risk of stroke, compared with those who ate no chocolate, suggesting that higher intakes are necessary for a potentially protective effect. Larsson's two-bar approximation was based on the effects associated with consuming about 66.5 grams or about 2.33 ounces, weekly.

The study followed 33,372 Swedish women, aged between 49 and 83, for about 10 years, beginning in the autumn of 1997. All of the women were asked to complete a questionnaire that included questions on more than 350 diet and lifestyle factors. During that decade, the researchers tallied 1,549 strokes among study subjects.

Larsson added that although this study was done exclusively with women, she expects the results to be similar for men. She noted that although chocolate made in the U.S. generally contained less cocoa than that made in Europe, there should be a benefit from chocolate consumption in the U.S. too.

In summary, results from this cohort of women suggest that a high chocolate consumption is associated with a lower risk of stroke, the authors of the study finally concluded.