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Dark chocolate said to boost stress resistance

A selection of couvertures from different cocoa beans Thomas Kern /

Consumption of dark chocolate helps protect against harmful stress and cardiovascular diseases, scientists at the universities of Bern and Zurich have found. They say further research is needed into the underlying mechanisms.

Half a bar of dark chocolate with high cocoa content substantially reduces bodily reactions to acute psychological stress two hours after consumption, according to a statement published on Monday.

The study, by a group of researchers led by Petra Wirtz from the psychology department of the University of Bern, measured stress hormones secreted in central parts of the body including the brain.

They found that male participants who were given 50 grams of dark chocolate showed lower reactivity of cortisol and epinephrine – hormones released in response to stress – than a control group which ate a similar placebo chocolate bar.

The researchers hope their study, published in the Journal of the American College of Cardiology, will provide new insights for the prevention of cardiovascular disease – the main cause of death in industrialised countries.

Psychosocial stress is an important risk factor for cardiovascular diseases.

The beneficial effects of cocoa flavonoids on blood pressure are well documented, but many open questions remain about the underlying mechanisms, according to the research team.

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SWI - a branch of Swiss Broadcasting Corporation SRG SSR

SWI - a branch of Swiss Broadcasting Corporation SRG SSR