When NZ kids suffer violence, does their DNA age at a faster rate?

International researchers have found that children who experience violence appear to be aging at a faster rate.

DNA of 236 British 10 year-olds exposed to violence during their childhood shows “erosion” of the special sequences at the tips of their chromosomes, the telomeres.

Such wear-and-tear is normally associated with ageing, and it limits the number of years that a given cell can go on dividing, the scientists say in a paper published in Molecular Psychiatry on April 24.

Children who experienced multiple forms of violence at a young age — such as  domestic violence, frequent bullying or physical maltreatment by an adult — had the fastest telomere erosion rate, regardless of other factors such as the child’s gender, poverty, weight or health.

Now the researchers plan to extend their study to over 1000 people born in Dunedin and now entering their 40s, in a bid to find what mechanism links childhood stress to accelerated aging, even at a young age at the fundamental level of their  cells.  Telomeres could be used as stress markers in research to evaluate the effects of stress, and the work suggests new urgency for preventing harm to children.

The same US-based researchers have previously studied NZ children (now entering their 40s) to show some may be genetically more resilient to abuse or other trauma, and they now about to investigate the Dunedin cohort  to see whether  those who experienced violence also  show extra wear and tear on their DNA.

One of the researchers, Professor Terrie Moffitt, of Duke University — who is also a Associate Director of the  Dunedin Multidisciplinary Health and Development Research Unit — told the SMC the latest research was done with British children born in 1994-1995. That cohort was established as a sister study to the group in Dunedin, where the children were all born in 1972-1973.

Professor Moffit said, in responsed to questions from the SMC:.

“In this new paper, we report that the British children who gave DNA samples at age 5 (in 2000) and again at age 10 (in 2005) showed more erosion of their telomeres, if the child had been exposed to stressful violence in the interim.

(Telomeres are caps on the ends of chromosomes that are related to a cell’s age).

“The violence included observing domestic violence between their mum and her partners, or the child being frequently bullied, or maltreated. The implication is that psychological stress might be able to accelerate cellular damage.

“What is new is that this had not been observed in children before, and that we tested telomeres twice to check for real change. (Prior studies had looked at adults, and had only tested telomeres once, so they could not prove there was change.)

“Many members of the Dunedin cohort have also given DNA for research. They gave samples at age 26 (1998) and recently again at age 38 (just completed last month).

“Because the finding from our British study is so interesting, we will also be conducting telomere assays for the Dunedin cohort. However, we will focus on health problems and stress experiences that occurred in the interim between the “before” and “after” DNA samples.

“For example, some Dunedin cohort members experienced the stress of the Brisbane floods or the Christchurch earthquakes. But also we will look to see if health problems have affected their telomeres. For example, some study members developed diabetes, migraine headaches, or severe infections since they were 26 years old.

“An especially interesting opportunity is to study whether an improvement in lifestyle has slowed telomere erosion.  Now that they have aged beyond the tumultuous twenties many Dunedin study members have stopped smoking, quit using drugs, improved their diet and exercise, cut back on alcohol, found their true love, and generally become more happy, settled, and satisfied with their lives . We will look for positive change in their telomeres. Fingers crossed!”