By Shaina Eagle
Growing up in a neighborhood plagued by gun violence, domestic abuse, and drug misuse does not just leave lasting mental and emotional impacts — it can affect your body on a molecular level. New research is showing the through-line between an individual’s childhood environment and the DNA molecules that carry the instructions for our body’s functioning.
A genetic analysis study suggests that violence experienced during childhood and adolescence can alter the expression of a person’s DNA. These changes influence genes related to the central nervous system and immune functioning. The changes might lead to poor health outcomes later in life.
A team of researchers from two universities found higher levels of genetic changes in participants who were exposed to higher levels of violence during childhood and young adulthood. Childhood violence has been shown to have both short- and long-term negative physical and mental health consequences.
“My interest was how something that is in your environment, like exposure to violence, like the stressors of everyday life, will change the DNA methylation,” said Forough Saadatmand of Howard University, who led the research team.
The study used DNA methylation to look at participants’ genes. Team member Douglas M. Ruden of Wayne State University explained DNA methylation using a computer analogy.
“The DNA would be the hardware, and the methylation parts would be the software,” Ruden said. “It tells you which genes are turned on and turned off, like a binary switch.” The gene alterations found in the study “could affect brain development or immune health,” Ruden said.
Methylation does not lead to permanent changes in the sequence of DNA molecules. But small molecular units called methyl groups can latch onto the DNA and influence how it is expressed, or read. Instead of deleting entire DNA molecules, methylation simply turns them off.
This study adds to a growing body of research that links adverse life experiences to changes in gene expression and negative health outcomes.
“The impact that violence has on our DNA, and how that impacts all aspects of health, are still just now being begun to be understood,” said Shani Buggs of the University of California, Davis, who was not connected to the study.
The current research focused on 32 young African American men in Washington, D.C. They were chosen from among a larger group surveyed about lifetime exposure to violence. Those with the highest and lowest exposure were chosen for study and comparison.
Blood samples were collected from the 32 participants and analyzed at Wayne State University. The researchers found that men with high exposure to violence had elevated methylation in 383 genes, most of which had ties to the nervous system and immune functioning.
The results were published in July 2021 in the journal Brain, Behavior, & Immunity – Health. The research was done at Howard University and Wayne State University. It was funded by grants from the National Institutes of Health and Howard University.
People from high-violence environments tend to have elevated rates of Alzheimer’s disease, bipolar disorder, Parkinson’s disease, post traumatic stress disorder, depression and anxiety, cardiovascular disease, and chronic inflammatory conditions. Research has also indicated a connection between DNA methylation and drug addiction. The genetic changes indicated in the current study may help explain the link between childhood environmental stressors and these health risks.
Showing how violence can affect our DNA is important for understanding how violence of years past may influence our health today, Buggs said. This study contributes to scientists’ understanding of how our environment influences health disparities.
Saadatmand said she hopes to pursue related studies in the future. She would like to conduct a similar study measuring lifetime exposure to violence and DNA methylation in females. She also wishes to explore the relationship of violence exposure and DNA methylation to long-term quality of sleep.
Shaina Eagle is a sophomore at the University of California, Davis majoring in global disease biology. She is on the editorial board of her university’s undergraduate life sciences journal, The Aggie Transcript. You can email her at sjeagle@ucdavis.edu.
This story was produced as part of NASW's David Perlman Summer Mentoring Program, which was launched in 2020 by our Education Committee. Eagle was mentored by Barbara Gastel.
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