Childhood stress shows up in DNA

The effects of early hardship are visible in our DNA, a new long-term study with orphanages shows.

Hanging out at the ends of our chromosomes, you’ll find little caps called telomeres (pictured). They shorten as chromosomes are replicated during cell division, making them a biological marker of aging.

Recent studies have linked stress to telomere shortening during adulthood, and this accelerated shortening has, in turn, been linked to health problems like heart disease, diabetes, and dementia.

Now, Tulane’s Stacy Drury and colleagues are the first to link childhood adversity to telomere length.

They looked at 136 children in the Bucharest Early Intervention Project. In this clinical trial of children from 6 to 30 months of age, half of them were placed into foster care while the other half remained in institutions.

The decade-old program aimed to compare the health and development of Romanian children brought up in an orphanage with children who received more individual attention and a better quality of care in foster families.

Using cheek swabs, the researchers obtained DNA samples from the children when they were between 6 and 10 years old. And then they measured the length of their telomeres.

The team revealed that the more time a child under 5 spent in group institutional care, the shorter their telomere lengths.

"We assumed that early and/or chronic adversity would have a deleterious effect on telomere length," says coauthor Charles Nelson of the Children's Hospital Boston.

Drury adds: "It shows that being in institutional care affects children right down to the molecular level.”

But perhaps their telomeres may lengthen again. Last week, the team received funding from the National Institutes of Health (NIH) to do a follow-up study of the Romanian children as they turn 12, Nature News reports:

The researchers have cognitive and physical health records from the children from multiple ages and are analyzing whether children from the two groups differ in terms of mental development and physical health. They will soon be able to compare these medical histories to their telomere lengths as 12-year olds.

The team is also currently measuring telomere length in children who experienced less stress in early childhood.

The study was published today in Molecular Psychiatry.

Image: telomere caps via Wikimedia Commons

This post was originally published on Smartplanet.com