"Descendants of Holocaust Survivors Have Altered Stress Hormones "

"Rachel Yehuda, a researcher in the growing field of epigenetics and the intergenerational effects of trauma, and her colleagues have long studied mass trauma survivors and their offspring. Their latest results reveal that descendants of people who survived the Holocaust have different stress hormone profiles than their peers, perhaps predisposing them to anxiety disorders...

It is not completely clear why survivors produce less cortisol, but Yehuda's team recently found that survivors also have low levels of an enzyme that breaks down cortisol. The adaptation makes sense: reducing enzyme activity keeps more free cortisol in the body, which allows the liver and kidneys to maximize stores of glucose and metabolic fuels—an optimal response to prolonged starvation and other threats. The younger the survivors were during World War II, the less of the enzyme they have as adults...

The enzyme is usually present in high levels in the placenta to protect the fetus from the mother's circulating cortisol. If pregnant survivors had low levels of the enzyme in the placenta, a greater amount of cortisol could make its way to the fetus, which would then develop high levels of the enzyme to protect itself...

With low levels of cortisol and high levels of the enzyme that breaks it down, many descendants of Holocaust survivors would be ill adapted to survive starvation themselves. In fact, that stress hormone profile might make them more susceptible to PTSD (below, yellow); previous studies have indeed suggested that the offspring of Holocaust survivors are more vulnerable to the effects of stress and are more likely to experience symptoms of PTSD."

http://www.scientificamerican.com/article/descendants-of-holocaust-survivors-have-altered-stress-hormones/

Note the mights - none of this us proven, but it's fascinating to consider and has a lot of implications about how big these traumas are. I know there have been similar findings related to the children of people present at the 9/11 attacks. Understanding this could help us provide people at high epigenetic risk with preventative measures.