Orphaned children lose many of the usual comforts of childhood when they enter institutional care. A new study of telomeres — strands of DNA at the ends of chromosomes that get shorter as people age — suggests that they might also lose time from their biological clock.

Research among adults has linked certain diseases and adverse life experiences with an accelerated shortening of telomeres. For this study, published online last week in the journal Molecular Psychiatry, researchers analyzed the telomere length of 100 orphaned children in Romania.

The children were participants in a larger, long-term study of institutional care vs. foster care; 52 had been moved into foster care as part of the project and 48 continued to live in institutions, which researchers characterized as an adverse experience.

A few years after the move, when the children ranged in age from 6 to 10, DNA from both groups was collected through cheek swabs and tested for telomere length. A significant correlation appeared: On average, the more time children had spent in an institution during their first 41 / 2 years of life, the shorter were their telomeres.

“It’s a strong argument that we have to pay attention to what happens to these kids,” said Stacy Drury, a lead author of the study and an assistant professor in psychiatry and pediatrics at Tulane’s School of Medicine. “We’re actually showing changes at the cellular level because of this kind of care.”

Drury said researchers plan to measure telomeres again as each of the children reaches age 12. At that point, there may be larger differences in telomere length, or possibly telomere recovery. Investigations are also underway with children in New Orleans. Adverse experiences such as the loss of a parent, living in poverty or being affected by Hurricane Katrina could take a toll on telomeres, too, Drury said.