A new study has found that stress related to violence could speed up the wear and tear of the DNA in children, aging them faster.
"This is the first time it has been shown that our telomeres can shorten at a faster rate even at a really young age, while kids are still experiencing stress," said Idan Shalev, post-doctoral researcher in psychology and neuroscience at the Duke University Institute for Genome Sciences & Policy.
Telomeres are special DNA sequences found at the tip of chromosomes; they prevent DNA from unraveling. Emerging evidence suggests that telomeres are "master integrators," connecting stress to biological age and associated diseases, the journal Molecular Psychiatry reported.
Telomeres are known to get shorter each time cells divide, putting a limit on the number of times a given cell can go on dividing.
Smoking, obesity, psychological disorders and stress have been found to possibly accelerate that process of telomere loss. In that sense, our telomeres may reflect biological age, not just chronological age, according to a university statement.
"Research on human stress genomics keeps throwing up amazing new facts about how stress can influence the human genome and shape our lives," said Avshalom Caspi, professor of psychology and neuroscience from Duke University.
Previous studies of telomeres and stress had primarily looked at telomeres in adults as they recalled experiences much earlier in their lives.
In the new study, Shalev took advantage of the twin study led by Caspi and Terrie Moffitt that has followed 1,100 British families with twins since the time those twins were born in the 1990s.
The twins are now 18-year-old adults, but the researchers performed the analysis on DNA samples collected when they were just five and 10-years-old.
Researchers also know, based on extensive interviews held with the twins' mothers, which of them experienced some form of violence in their younger years, including domestic violence, frequent bullying or physical maltreatment by an adult.
The new report shows that a subset of those children with a history of two or more kinds of violent exposures have significantly more telomere loss than other children. Since shorter telomeres have been linked to poorer survival and chronic disease, this may not bode well for those kids.