Scientists Find That Genetic Changes From Trauma Suffered by Holocaust Survivors Can Be Passed To Their Children

(3BL Media/Justmeans) – Scientists have discovered that the trauma experienced by one generation can alter genes and that those mutations can be passed along to children. These latest findings are a clear example of the theory of epigenetic inheritance - that environmental factors can affect the genes of your children and that genetic changes stemming from the trauma suffered by Holocaust survivors are capable of being passed on to their children. This is the conclusion from a study at Mount Sinai hospital and the James J. Peters Veterans Affairs Medical Centre, both in New York, which has been published in Biological Psychiatry.

The research led by Rachel Yehuda at Mount Sinai hospital looked at the genetics of 32 Jewish men and women who had been persecuted by the Nazis, held prisoners in a concentration camp, witnessed or experienced torture or who had had to hide during the Second World War. Yehuda’s team analysed the genes of their children, who are known to have increased likelihood of stress disorders, and compared the results with Jewish families who were living outside of Europe during the war. The study concluded that the gene changes in the children could only be attributed to Holocaust exposure in the parents.

Our genes are altered by the environment continuously, through chemical tags that attach themselves to our DNA, switching genes on and off. Recent studies suggest that some of these tags might somehow be passed through generations, meaning our environment could have an impact on our children’s health. This research team were interested in one region of a gene associated with the regulation of stress hormones, which is known to be affected by trauma. They found epigenetic tags on the very same part of this gene in both the Holocaust survivors and their offspring, the same association was not found in any of the control group and their children. It’s still not clear how these tags might be passed from parent to child.

Yehuda's team including the James J. Peters Veterans Affairs Medical Centre and others had previously established that survivors of the Holocaust have altered levels of circulating stress hormones compared with other Jewish adults of the same age. Survivors have lower levels of cortisol, a hormone that helps the body return to normal after trauma; those who suffered post-traumatic stress disorder have even lower levels.

It is not clear why survivors produce less cortisol, but Yehuda's team found that survivors also have low levels of an enzyme that breaks down cortisol. The adaptation makes sense: reducing enzyme activity keeps freer cortisol in the body, allowing the liver and kidneys to maximise stores of glucose and metabolic fuels—an optimal response to prolonged starvation and other threats.  This research shows that science is starting to understand how one generation responds to the experiences of the previous generation, and is fine-tuning the way our genes respond to the world.

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