London: Violence in tender age puts wear and tear in kids` DNA, say researchers.
A new study by a Duke University study found that the DNA of 10-year-olds who experienced violence in their young lives has been altered.
"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, who led the team.
Telomeres are special DNA sequences found at the tips of chromosomes; much like the plastic tips of shoelaces, they prevent DNA from unraveling. Emerging evidence suggests that telomeres are "master integrators", connecting stress to biological age and associated diseases.
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.
In the study, the researchers 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.
The 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 maltreatment by an adult.
The new report, in the `Molecular Psychiatry` journal, 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, say the researchers.
"Research on human stress genomics keeps throwing up amazing new facts about how stress can influence the human genome and shape our lives," said the researchers.