Early exposure to violence may alter children’s DNA to produce cellular changes equivalent to seven to ten years of premature aging, according to a new study.
While scientists have previously found associations between childhood stress and later disease risk and health problems, the latest study is the first to link stress to accelerated biological aging in childhood.
Researcher Idan Shalev at the Duke Institute for Genome Sciences & Policy said that children who’ve experienced violence are older than their years, and if their stress-caused cellular aging isn’t reversed, they are more at risk for premature death.
Shalev and colleagues measured biological aging by studying protective caps on the ends of chromosomes called telomeres, a portion of DNA that gets shorter with every cell division over time and signals the wear-and-tear on DNA.
Past studies have shown that adults who’ve experienced violence as children generally had shorter telomeres compared to those with nonviolent childhoods, but scientists were unable to determine whether the telomeres had eroded because of childhood stress or because of later health problems produced by the earlier stress.
The study consisted of 236 British children born between 1994 and 1995. According to interviews with the children’s mothers, 17 percent of the children by the time they turned 10 had experienced domestic violence in their households, 24 percent had been frequently bullied and 27 percent had been physically abused by an adult.
After comparing lengths of telomeres from DNA samples swabbed from children’s cheeks at age 5 and age 10, researchers found that kids with a history of two or more kinds of violent experiences have significantly more telomere erosion in those five years compared to other children.
It is still unclear as to how cumulative stress can cause telomere shortening, but researchers suggest that inflammation, an immune response to stress, may play a role in telomere erosion.
"We know that violence is associated with higher inflammation levels," he said, according to Live Science. "Higher inflammation levels are associated with shorter telomere length."
Researchers said that a healthy diet, physical activity and meditation, which are associated with longer telomeres, can stop telomeres from shortening.
Co-author Professor Terrie Moffitt at Duke said that the findings, which highlighted the long-term damage childhood stress can create, show that more needs to be done to protect children.
“An ounce of prevention is worth a pound of cure,” Moffitt said in a statement. “Some of the billions of dollars spent on diseases of aging such as diabetes, heart disease and dementia might be better invested in protecting children from harm.”