Black chocolate protects against stress

Dark chocolate reduces the release of stress hormones

08/04/2014

Dark chocolate with high cocoa content is said to have many beneficial effects on the cardiovascular system. Here, the flavonoids contained play a crucial role. The way in which they reduce the risk of cardiovascular diseases, however, has not yet been conclusively clarified. Scientists from the Universities of Berne and Zurich have now shown that bitter chocolate has an influence on the release of stress hormones and thus protects against the negative health consequences of stress.

„Psychosocial stress“ According to a statement by the University of Bern, it is an important risk factor for cardiovascular diseases, which in turn are among the leading causes of death in industrialized countries. „In particular, brief episodes of intense stress can trigger an acute myocardial infarction through biological changes“, reports the University of Bern. According to current findings, bitter chocolate develops its protective effects by reducing the release of stress hormones. Added to this are the positive effects of cocoa flavonoids on classic cardiovascular risk factors such as blood pressure or blood lipids, which have already been proven in previous studies, reports the University of Bern. Study leader Petra Wirtz, Professor of Biological Psychology and Health Psychology at the University of Bern, comes to the conclusion that „Consumption of black chocolate from death by cardiovascular disease“ protects and for that „certain cocoa ingredients, the cocoa flavonoids“, are responsible.

Chocolate with significant impact in the stress test
In their study, researchers in a group of healthy male subjects between the ages of 20 and 50 administered half a tablet of high flavonoid black chocolate, while a control group received optically comparable placebo without flavonoids. The placebo chocolate was an original one „white chocolate dark colored and flavored to resemble the look and taste of black chocolate“, explained Prof. Wirtz. Two hours after consumption, the subjects were subjected to a standardized 10-minute psychosocial stress test, which consisted of a fictitious interview with free speech and mental arithmetic before two examiners. According to Prof. Wirtz dissolves „this stress test reliably relieves an acute physical stress response associated with a release of stress hormones.“ The scientists wanted to know exactly and observed in parallel the concentration of stress hormones, „which are released on the one hand by the adrenals and on the other hand predominantly in central parts of the body such as the brain.“ In addition, the subjects should assess the perceived stress on the basis of a questionnaire. The researchers also measured the flavonoid level in the blood.

Less cortisol and adrenalin spilled
The most important result is that subjects who had eaten dark chocolate, „lower increases in the adrenal stress hormones cortisol and adrenaline compared to the placebo group“ showed, reports the University of Bern. „The higher the flavonoid levels in the subjects' blood, the lower the stress reactivity of these hormones“, explained Prof. Wirtz. However, the release of the predominantly centrally distributed stress hormones and the psychological stress assessment via the questionnaire would not have revealed any differences between the study groups. The researchers conclude, „It protects the black adrenaline flavonoids from the physical reaction to stress by reducing the release of stress hormones.“ The results of the study were published in the journal „Journal of the American College of Cardiology“ released. (Fp)