The result of this study, combined with other research, seems to indicate that childhood trauma such as child abuse, not only harms the victim, but can cause the victim’s children to be less healthy.
Harvard researcher Dr. Andrea Roberts and others conducted a long-term study, coordinated by Harvard’s TH Chan School of Public Health, to look for the possible effects of child abuse on victims’ genetic material. The results, published in the journal Translational Psychology, show a strong link between abuse and DNA alteration.
The study examined 34 men—22 of which had been abused as children—and found 12 different sites on victims; DNA which had been affected by a process called “methylation.”
How Methylation Works
Methylation occurs when a chemical compound called a “methyl group” attaches to a person’s DNA and affects the way that DNA operates.
A methyl group—a carbon atom with three hydrogen atoms attached—can attach itself to a person’s DNA and once in place, generally suppresses some genes’ functions.
The resultant mutation can be passed on through sperm from one generation to the next—which means that trauma such as child abuse might permanently alter a family’s future generations.
“We already know there are a lot of behavioral mechanisms by which trauma has negative effects on the next generation,” Roberts told The Independent.
“Trauma obviously really affects the behavior of people traumatized. It often makes them depressed, it gives them post-traumatic stress disorder, and those mental health conditions affect their parenting and affect the kids. This is another possible pathway,” she said.
The study in question could not study multiple generations of people, but research on mice shows that parents stressed severely early in their lives tend to have offspring with health problems.
Possible Effects on Future Generations
“Some very good findings from mice have shown that early life stressors affect the marks on the sperm, and then, in turn, those affect the health of the offspring, in particular, creating a kind of anxious behavior,” Roberts explained.
Roberts’s earlier work showed a link between traumatic stress and various health problems, including cardiovascular disease, diabetes, gastrointestinal disease, fibromyalgia, chronic fatigue syndrome, and musculoskeletal disorders.
The new research shows that the children of abused children might inherit some of the same risks.
Roberts has also studied the effect of childhood abuse on women and the likelihood that women abused as children gave birth to autistic children.
Dr. Michael S. Kobor, a professor of Medical Genetics at the University of British Columbia, was the senior author of the Harvard child abuse study.
Kobor has written seminal works on how childhood environment and experience can change DNA.
He hypothesized that eventually, scientists might be able to identify the victims of child abuse and testify in court cases concerning the crime.
“Methylation is starting to be viewed as a potentially useful tool in criminal investigations—for example, by providing investigators with an approximate age of a person who left behind a sample of their DNA,” Kobor told Medical Xpress.
“So it’s conceivable that the correlations we found between methylation and child abuse might provide a percentage probability that abuse had occurred.”
Roberts made it clear that while the findings of the research were significant, they were preliminary. Even though the sperm cells of child abuse victims are altered, it is unclear whether or how the resulting offspring might be affected.
“When the sperm meets the egg, there is a massive amount of genetic reshuffling, and most of the methylation is at least temporarily erased,” Roberts explained. “But finding a molecular signature in sperm brings us at least a step closer to determining whether child abuse might affect the health of the victim’s offspring.”