Stress and trauma can literally change your DNA — and the DNA of your kids and grandkids
We’ve long known the short-term effects of trauma — headaches, changes in appetite or sleep, fear, anxiety and concentration troubles are just a few.
A new study suggests that severe trauma, like that experienced in war, can leave epigenetic “scars” on DNA that endure generations.
The concept of intergenerational trauma is not new — the passing of traumatic experiences to descendants has been shown to significantly increase their likelihood of depression and other mental health issues.
This research confirms the phenomenon with an analysis of DNA from 48 Syrian families across three generations.
“The study documents the signatures of stress and trauma in the body, under the skin,” said Yale University anthropologist Catherine Panter-Brick.
“Our findings present the first-ever evidence that violence can leave epigenetic marks on the genome, which has important implications for understanding evolution and how traumatic experiences can become embedded in the genome and persist for generations,” she added.
Panter-Brick’s team studied women who were pregnant during violent Syria conflicts in the early 1980s or 2011.
The DNA of 10 families exposed to the ’80s violence and 22 families to the 2011 conflict was compared to the genetic material of 16 families who left Syria before 1980, avoiding decades of unrest.
In all, cheek swabs were collected from 131 people — 45 younger children, 37 older children, 47 mothers and two grandmothers.
“The participants took part in the research out of love for their children and concern for future generations,” said study co-author Dima Hamadmad, a Syrian researcher and the daughter of refugees. “But more than that, they wanted their stories of trauma to be heard and acknowledged.”
The researchers examined 850,000 sites of DNA methylation, where small chemical tags called methyl groups are added to DNA.
This process can alter gene expression without changing the underlying DNA sequence.
The researchers identified 21 sites in the DNA of mothers and children who had directly experienced violence that showed signs of altered epigenetic markings.
Modifications in 14 genome areas were found in the grandchildren of women who survived the ’80s attack.
The researchers also reported that those exposed to violence while in their mothers’ wombs appeared to be aging faster at a cellular level. It’s not clear what effect, if any, these changes may have on their health.
The findings were published last month in the journal Scientific Reports.
The study authors are calling for more research into the lasting effects of violence — domestic violence, sexual violence, gun violence and more.
“The idea that trauma and violence can have repercussions into future generations should help people be more empathetic, help policymakers pay more attention to the problem of violence,” co-senior study author Connie Mulligan said.
“It could even help explain some of the seemingly unbreakable intergenerational cycles of abuse and poverty and trauma that we see around the world, including in the US,” she added.
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