Harsh words and feelings of rejection by others create stress that can increase the predisposition to develop inflammatory diseases such as arthritis, according to a study published in the Proceedings of the National Academy of Science.
Such conclusions were reached by psychologists from the University of California in Los Angeles, led by George Slavich, who conducted a study on a group of 124 healthy volunteers. All of them were to give a speech and perform an arithmetic exercise in mind in front of an audience treating them with disdain and contempt.
Analysis of saliva samples from them revealed elevated levels of two compounds associated with inflammation in the body, ie the soluble receptor for tumor necrosis factor alpha (sTNF RII) and interleukin-6 (IL-6).
A quarter of the volunteers then took part in a computer game in which each of them was excluded by other players. At the same time, their brain was examined using functional magnetic resonance imaging (fMRI).
Rejection by other players increased the activity of two areas of the brain (i.e. the front dorsal cingulate cortex and the front of the island) that had previously been linked to the emergence of negative feelings in response to rejection. It turned out, however, that the activity of these two structures increased most strongly in people who previously had the highest increase in the concentration of sTNFγRII (but not IL-6).
The authors believe that it will help to better understand the role of the brain in the development of inflammatory processes in response to severe social stress. Thanks to this, it will be easier to explain the impact of this stress on the predisposition to inflammatory diseases such as rheumatoid arthritis, asthma or diseases of the cardiovascular system. (PAP)