Apr 30, 2012
The prevalence of children who are exposed to violent victimization is substantial and occurs to almost a quarter of children. We know that children who experience severe stress grow up have many health problems as adults. But we don’t know exactly how this might happen. Or what are the mechanisms.
In a recent study, we helped to address the question of how and when childhood stress gets
“under the skin” at the cellular level. To answer this question, we tested the effect of stress during childhood on telomeres, which are special elements at the tip of our chromosomes; much like the plastic tips of shoelaces, they prevent our DNA from unraveling. Telomeres get shorter each time cells divide, and we know today that telomeres may reflect our biological age. What we showed, for the first time, is that cumulative violence exposure was associated with accelerated telomere erosion, from age 5 to age 10, among children who experienced violence at a young age. Children who were exposed to multiple forms of violence had the fastest telomere erosion rate.
But what are the mechanisms linking childhood violence victimization to accelerated telomere erosion? At this point of time, we still don’t know the exact answer. Most of the insights about mechanisms linked with telomere erosion originate from research on oxidative stress (free radicals in our cells) and inflammation, indicating both as important influences on telomere length. We know that childhood stress predicts elevated inflammation, suggesting a possible cause for the increased telomere erosion observed in victims of violence. However, more studies are needed to test whether effects of stress on telomere erosion are mediated by oxidative stress, immune-system changes, or other factors in children who are exposed to violence.
Idan Shalev is a postdoctoral fellow in the department of psychology & neuroscience at Duke University.