An Inheritance of Trauma

Epigenetics seems to be growing up and facing the inevitable questions that come to a maturing science. A new study of trauma experienced by POWs in the Civil War adds to the evidence that sons (perhaps even grandsons) can inherit the physical effects of that trauma. So naturally, people are asking hard questions about these findings.

Sons of Trauma Dying Sooner

Dora Costa and colleagues published their findings in Proceedings of the National Academies of Sciences. They studied children of Civil War POWs who lived through terrible, traumatic conditions late in the war. They compared them to children of the war’s veterans who were never imprisoned. Also, to POWs who had less harsh treatment.

The primary endpoint was how many years the person lived beyond the age of 45. For sons of trauma, they found a risk of death as much as 20 percent higher. But they found no effect for daughters, suggesting the risk may be linked to the Y chromosome.

They also found a that good maternal nutrition might have a protective effect. They found no effect when sons were born during periods of good maternal nutrition.

Impossible to Rule Out Other Factors

The authors are very clear. “We cannot rule out fully psychological or cultural effects.” But, they say, “Our findings are most consistent with an epigenetic explanation.”

Critics of this nascent science contend that it lacks adequate rigor. Professor Kevin Mitchell says:

These are, in fact, extraordinary claims, and they are being advanced on less than ordinary evidence. This is a malady in modern science: the more extraordinary and sensational and apparently revolutionary the claim, the lower the bar for the evidence on which it is based, when the opposite should be true.

A Long Way to Go

This skepticism is healthy, but hardly the final word. Evidence has been building for at least a decade. It started with the Dutch famine study in 2008. Children exposed in the womb to the Dutch Hunger Winter were born with epigenetic changes that marked them for later health problems. Including more obesity.

Epigenetic studies of holocaust survivors and poverty victims added to the evidence that we can inherit the effects of trauma. Animal research is only just starting to explain the mechanisms.

Regardless, we can find good news in all of this. An inheritance of trauma is not an inevitability. Says Costa:

By no means is it saying that whenever there’s trauma, that means it’s going to be transmitted. The epigenetic story is optimistic because it allows for the possibility of reversibility through maternal nutrition.

Click here for the study by Costa et al. For further perspective, click here and here. For a deeper dive on the genetics and epigenetics of obesity, click here.

Generations, photograph © Ray Dumas / flickr

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December 12, 2018