Violence ages children's DNA, shortens their chromosomes

Violence ages children's DNA, shortens their chromosomes
                                  
By Liz Szabo, USA TODAY

....Study finds that exposure to violence can cause changes in DNA leading to seven to 10 years of premature aging.

In fact, a new study suggests that violence leaves long-term scars on children's bodies - not just in bruises on the skin, but also altering their DNA, causing changes that are equivalent to seven to 10 years of premature aging.

Scientists measured this cellular aging by studying the ends of children's chromosomes, called telomeres, according to Idan Shalev, lead author of a study in today's Molecular Psychiatry.

Telomeres are special DNA sequences that act like the plastic tips on shoelaces, which prevent the DNA in chromosomes from unraveling. They get shorter each time a cell divides, until a cell can't divide anymore and it dies....

In this study, researchers examined whether exposure to violence could make children's telomeres shorten faster than normal. They interviewed the mothers of 236 children at ages 5, 7 and 10, asking whether the youngsters had been exposed to domestic violence between the mother and her partner; physical maltreatment by an adult; or bullying. Researchers measured the children's telomeres — in cells obtained by swabbing the insides of their cheeks — at ages 5 and 10.

Telomeres shortened faster in kids exposed to two or more types of violence, says Shalev, a post-doctoral researcher at the Duke Institute for Genome Sciences & Policy in Durham, N.C. Unless that pattern changes, the study suggests, these kids could be expected to develop diseases of aging, such as heart attacks or memory loss, seven to 10 years earlier than their peers....

The study confirms a small-but-growing number of studies suggesting that early childhood adversity imprints itself in our chromosomes, says Charles Nelson, a professor of pediatrics and neuroscience at Harvard Medical School.

In a 2011 study, Nelson and colleagues found shorter telomeres in Romanian children who had spent more time in institutions, compared with children sent to foster care. http://www.usatoday.com/news/health/story/2012-04-24/violence-cellular-mark/54493338/1?csp=34news




Molecular Psychiatry , (24 April 2012) | doi:10.1038/mp.2012.32
Exposure to violence during childhood is associated with telomere erosion from 5 to 10 years of age: a longitudinal study
I Shalev, T E Moffitt, K Sugden, B Williams, R M Houts, A Danese, J Mill, L Arseneault and A Caspi

Abstract
There is increasing interest in discovering mechanisms that mediate the effects of childhood stress on late-life disease morbidity and mortality. Previous studies have suggested one potential mechanism linking stress to cellular aging, disease and mortality in humans: telomere erosion. We examined telomere erosion in relation to children's exposure to violence, a salient early-life stressor, which has known long-term consequences for well-being and is a major public-health and social-welfare problem. In the first prospective-longitudinal study with repeated telomere measurements in children while they experienced stress, we tested the hypothesis that childhood violence exposure would accelerate telomere erosion from age 5 to age 10 years. Violence was assessed as exposure to maternal domestic violence, frequent bullying victimization and physical maltreatment by an adult. Participants were 236 children (49% females; 42% with one or more violence exposures) recruited from the Environmental-Risk Longitudinal Twin Study, a nationally representative 1994–1995 birth cohort. ....Compared with their counterparts, the children who experienced two or more kinds of violence exposure showed significantly more telomere erosion between age-5 baseline and age-10 follow-up measurements, even after adjusting for sex, socioeconomic status and body mass index (B=-0.052, s.e.=0.021, P=0.015). This finding provides support for a mechanism linking cumulative childhood stress to telomere maintenance, observed already at a young age, with potential impact for life-long health. http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201232a.html