Dark chocolate consumption protects from cardiovascular diseases but underlying mechanisms are not fully understood.
Research from the Universities of Bern and Zürich and the Bern University Hospital (Inselspital) suggests that a single intake of half a bar of dark chocolate with high cocoa content substantially reduces bodily reactions to acute psychological stress two hours after consumption. Since mental stress is a known cardiovascular risk factor dark chocolate thus may add to the protection of the cardiovascular system from harmful stress effects.
Prof. Dr. Petra H. Wirtz, PhD, Biological and Health Psychology, Department of Psychology, University of Bern
Prof. Dr. Roland von Känel, M.D., Division of Psychosomatic Medicine, Inselspital, Bern University Hospital
Cardiovascular diseases are the leading cause of death in industrialized countries. Psychosocial stress is an important psychological risk factor for cardiovascular diseases. In particular, short episodes of strong emotional stress induce biological changes that, in turn, can trigger acute myocardial infarction. Consumption of dark chocolate substantially lowers cardiovascular mortality due to the contained cocoa flavonoids.
Whereas beneficial effects of cocoa flavonoids on classical cardiovascular risk factors such as blood pressure or blood lipids are well documented, many open questions remain regarding underlying mechanisms. A group of researchers led by Petra H. Wirtz, PhD, from the Department of Psychology of the University of Bern in Switzerland investigated for the first time whether in humans the intake of dark chocolate would protect from physiological effects of acute mental stress.
In a placebo-controlled study half of the healthy male participants had to consume either 50 g of dark chocolate with high cocoa content or an identically looking placebo chocolate without cocoa. The latter was an initially white chocolate that was flavored and dyed darkly in order to match the color and taste of dark chocolate. Two hours later, all participants had to perform a 10-minute mental stress test that included a mock job interview by two non-supportive persons wearing white coats.
This stress test is known to activate the body to produce stress hormones.
The researchers measured stress hormones that are released by the adrenal gland, an organ in the periphery of the body, as well as stress hormones that are primarily secreted in central parts of the body including the brain. All stress hormones were measured before and up to one hour after stress. In addition to a psychological measure of stress cocoa flavonoid levels were measured in the blood of the participants.
Results showed that the group of participants that consumed dark chocolate showed a lower stress reactivity of the adrenal stress hormones cortisol and epinephrine. The higher the measured flavonoid levels in the blood the lower was the reaction of these stress hormones to the stress test. There were no differences between the dark chocolate group and the placebo group regarding stress hormones secreted more centrally as well as in the psychological stress measure.
«We assume that dark chocolate protects from physiological reactivity to mental stress at the level of the adrenal gland by reducing stress hormone secretion», says Dr. Wirtz. The researchers hope that their results will add to a better understanding of the protecting effects of cocoa flavonoids on the cardiovascular system and that they may provide new insights for prevention of cardiovascular disease in both, risk populations and healthy persons. Results of the study have been published ahead of print in the journal «Journal of the American College of Cardiology (JACC)».
Prof. Dr. Petra H. Wirtz, PhD
Biological and Health Psychology, Department of Psychology, University of Bern
Tel. 0041 31 631 57 90 / firstname.lastname@example.org
Prof. Dr. Roland von Känel, M.D.
Division of Psychosomatic Medicine, Inselspital, Bern University Hospital and Department of Clinical Research University of Bern
Tel. 0041 31 632 20 19 / email@example.com
Markus Hächler | idw - Informationsdienst Wissenschaft
Hot cars can hit deadly temperatures in as little as one hour
24.05.2018 | Arizona State University
3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Ecology, The Environment and Conservation
24.05.2018 | Medical Engineering
24.05.2018 | Physics and Astronomy