Stress makes you sick by changing your genes

Most of us are well aware that stress dramatically heightens our susceptibility to contracting illnesses — both physical and psychological. Scientists have known about this link for decades, but have often struggled to describe the actual mechanics involved. But new research from the Ruhr-Universität Bochum (RUB) is now indicating that genetics may be a contributing factor — or more accurately epigenetics. It now appears that stress may actually contribute to the onset of diseases by changing our very genes.

Specifically, acute environmental stress has been shown to change the methylation of DNA, which in turn alters the activity of certain genes. Epigenetic information determines which genes are read and how they're to be expressed (a kind of biological switch), and are often regulated by environmental factors. And as this new study indicates, it's these stress-induced changes to genetic expression that are responsible for an increased risk of contracting mental or physical illnesses.

To reach this conclusion, Gunther Meinlschmidt and his team examined two specific genes: the gene for the oxytocin receptor (which is commonly known as the "trust hormone" or the "anti-stress hormone"), and the gene for the nerve growth factor Brain-Derived Neurotrophic Factor (BDNF) (which contributes to the development and cross-linking of brain cells).

In order to observe the influence of stress on these genes, the research team gathered 76 test subjects and had them participate in a fictitious job interview where they had to solve complex arithmetic problems while under observation. The researchers took blood samples of the participants both before and after the test.

What they discovered was that acute stress had no impact on the methylation of the BDNF — but its impact on the oxytocin receptor gene was a different story. Methylation of this gene increased within the first ten minutes of the experiment, forming less oxytocin receptors. And ninety minutes after the test the methylation dropped below the original level — an indication that the receptor production was significantly stimulated.

Meinlschmidt and his team concluded that stress increases the risk of physical or mental illness by means of epigenetic alterations. Consequently, they believe that a link may exist between stress and chronic diseases such as cancer and depression. As a result, the researchers are hoping to find more complex epigenetic stress patterns to determine the associated risk of disease in order to provide new information on new approaches to treatment and prevention.

The entire study can be read at Translational Psychiatry.

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