Historical trauma linked to DNA changes in Alaska Natives
A new genetic study has demonstrated links between the experience of historical trauma and changes in DNA among Alaska Natives.
Though the researchers have yet to understand the potential health effects of these changes, they say that it’s further proof trauma leaves hidden scars that get passed down through generations.
“Scientifically, we can prove that our people have suffered from intergenerational trauma, and now we want to deal with it,” said Rosita Worl, a co-author of the study and the president of Sealaska Heritage Institute, a nonprofit organization in Southeast Alaska.
The findings were published in the International Journal for Equity in Health in September.
In total, 117 Alaska Natives participated in the study from Southeast Alaska and the Kenai Peninsula. They completed surveys on cultural identification, historical trauma and general wellbeing. Some of those questions involved asking participants how intensely they felt symptoms like sadness, anger or anxiety when they reflected on historical traumas that their community experienced.
Participants also provided a blood sample so that the researchers at the University of Illinois at UrbanaChampaign could search for signs of DNA methylation.
A person’s DNA sequence remains stable during their lifetime. But parents don’t just pass down this simple genetic code to their kids. They can also acquire changes to their DNA, known as epigenetic changes, that can get passed down, too. One type of change is known as DNA methylation, in which parts of the DNA molecule can get covered up, which can affect the way those genes are expressed.
“It’s a chemical modification to the DNA strand, and it can serve as a signal for gene expression,” said study lead author Mary LaVanne, who conducted the analysis while a postdoctoral researcher at the University of Illinois. “A lot of people think of it not as a light switch, but like a dimmer.”
This “dimmer” can turn up or turn down the expression of genes.
In this study, the geneticists looked at over 850,000 sites on the DNA strand where this methylation can occur.
Participants who had more intense symptoms when they reflected on traumatic events in their community’s history were more likely to have DNA methylation of specific genes, the study found. Some of these genes had been previously linked to trauma in other studies, including one that looked at the genetic effects of social deprivation in children in a Russian orphanage.
Previous studies have found trauma-related changes genes involved in immune response, stress response and other functions. But this field is still in its infancy, and LaVanne explained that further research would be needed to link these changes to any specific health outcomes.
“Whether or not we know their functional relevance, the fact that there is this physiological difference is further evidence of how historical trauma can affect someone’s body,” LaVanne said.
During the AFN convention last month, Worl told the Nugget in an interview that Sealaska had previously worked with University of Illinois anthropologist Ripan Malhi on other projects. When she heard that Malhi’s team was investigating intergenerational trauma among tribal members in the Kenai region, Worl wanted the Southeast region to be involved as well.
Malhi said that the study used “community-engaged protocols,” meaning their methods were informed and approved by their community partners before proceeding. He added that the results, and implications of the results, were discussed extensively with the partner communities.
Discussions about boarding schools, forced sterilization, and other traumatic impacts of colonial violence were not to be approached lightly. Worl explained that even lectures about these subjects can be retraumatizing for many individuals.
“We knew that it could have a negative impact on our people, so we were prepared for that,” Worl said.
Because the survey questions and study results could be upsetting, counselors were on hand for participants to talk to at every stage.
One of the results that surprised Worl was that DNA changes were evident in seemingly healthy families.
“That caused grief to the parents because they thought they were responsible and were feeling guilty that maybe they did the wrong thing,” Worl said.
But the study also added validation to the cultural integration and revitalization work of Sealaska and other Alaska Native organizations. Participants in the study who had a strong sense of personal identification in Alaska Native culture tended to report better general wellbeing, the researchers found.
“We see that integrating language and culture has a beneficial impact,” Worl said. “For our students, we’ve seen increases in academic achievement, we’ve seen decreases in school dropout rates. Even in our traditional games, we’ve seen how it helps students. So, the study was good in validating that there are real concrete impacts on our bodies.”
Worl said she saw some benefits for her community being able to scientifically prove that they’ve been affected by trauma. This new evidence could help communities get funding needed to deal with traumarelated problems they’re facing, such as disproportionate health impacts.
As the authors of the study wrote in their conclusion: “Indigenous communities have been stigmatized for public health issues instead caused by systemic inequalities, social disparities, and discrimination.”
They argue that “the vast impact of historical trauma and ongoing colonial violence” should be considered as important factors that influence the health of Alaska Natives.