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Eating chocolate helps keep your heart beating


Study adds to evidence supporting the health benefits of chocolate consumption. Andrew Masterson reports.


Chocolate consumption may help stave off atrial fibrillation.
Kelvin Murray / Getty

Want to do something good for your heart? Eat some chocolate. Want to do something even better for your heart? Eat some more chocolate.

That’s the slightly surprising finding derived from examining the dietary habits of 55,500 Danes over a period of 14 years.

The study, led by epidemiologists from Harvard University, looked at the relationship between chocolate consumption and the occurrence of an often-fatal type of irregular heartbeat known as atrial fibrillation (AF).

Drilling through the data accumulated for the participants in the Danish Diet, Cancer, and Heath Study, the researchers uncovered 3,346 cases of AF over a 13-and-a-half year period.

The heart disease patients were classified according to their body-mass index, blood pressure, cholesterol, lifestyle, diet and other health problems. The entire study cohort was asked to estimate the size and frequency of chocolate consumption, with individuals then ranked and correlated against AF case frequency.

The baseline was established to be those who ate less than 28 grams (one ounce) per month. Compared to this, people who enjoyed between 28 and 84 grams a month had a 10% lower risk of atrial fibrillation.

People who ate 28 grams per week showed a 17% lower risk, while folk who snarfed between 56 and 168 grams a week had a 20% lower risk.

Scoffing even more than this produced a plateau, with AF risk reducing by 16%.

Results were identical for men and women.

"Our study adds to the accumulating evidence on the health benefits of moderate chocolate intake and highlights the importance of behavioral factors for potentially lowering the risk of arrhythmias," says lead author Elizabeth Mostofsky.

Several previous studies have identified cocoa-containing foods as conferring heart health benefits, with flavanols – naturally occurring phyto-proteins – thoughtt be the principal driver.

However, a Swedish study published earlier this year revealed a more complex result. While moderate consumption of chocolate was found to be associated with lower rates of heart failure, the positive effect vanished in people who ate it daily.

In most studies, any observed benefits appear highest in dark chocolate, perhaps because it contains less fat and sugar content.

The Danish participants were not instructed to eat any particular kind of chocolate and so were likely, in the main, to have chowed down on popular milk-chocolate varieties.

Says Mostofsky: "Despite the fact that most of the chocolate consumed by the study participants likely had relatively low concentrations of potentially protective ingredients, we still observed a significant association between eating chocolate and a lower risk of AF -- suggesting that even small amounts of cocoa consumption can have a positive health impact."

The study is published in the journal Heart.

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Andrew Masterson is news editor of Cosmos.
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