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 / email@example.com
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 / firstname.lastname@example.org
Markus Hächler | idw - Informationsdienst Wissenschaft
Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania
The strange double life of Dab2
10.01.2017 | University of Miami Miller School of Medicine
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering