Recently, Petra Wirtz and colleagues from the Department of Psychology, University of Bern, Switzerland demonstrated perhaps for the first time that consumption of dark chocolate is linked to lower stress reactivity.
Evidence indicates a beneficial effect of cocoa flavonoids on cardiovascular health. However, little is known about the effect of dark chocolate consumption on the stress system and its reactivity.
In this study, participants consumed either 50 g of dark chocolate with high cocoa content or an identically looking placebo chocolate without cocoa. The authors found that individuals having high flavonoid levels in the blood expressed low reaction of the adrenal stress hormones cortisol and epinephrine (adrenaline) to a Trier Social Stress Test (TSST).
Interestingly, in another, more recent study, published in Thrombosis and Haemostasis Journal, the same research team has also shown that a consumption of flavonoid-rich dark chocolate blunted the acute prothrombotic response to psychosocial stress.
As psychosocial stress is a known risk factor for cardiovascular disease development, these studies may suggest a peripheral stress-protective effect of dark chocolate consumption. The authors suggest that this may contribute, to some extent, to a reduced risk of acute coronary syndromes triggered by emotional stress.