Exercise, a healthy diet and good sleep can protect the body against the negative effects of stress and slow down the aging process at a cellular level, researchers report.

A study involving hundreds of older women found that stressful events are linked to increased shortening of telomeres, the protective caps at the ends of chromosomes that affect how quickly cells age.

"We found that over a one-year period, the more stressors a woman had, the more their telomeres were likely to shorten," said lead author Eli Puterman, assistant professor of psychiatry at the University of California, San Francisco School of Medicine.

But women who maintained active lifestyles, ate right and slept well appeared to shrug off the effects of stress, with their telomeres showing no significant additional shortening, the researchers said.

Dr. Michael Speicher, professor and chairman of the Institute of Human Genetics at the Medical University of Graz in Austria, said the study "addresses a really important biological question: why a healthy lifestyle is really helpful, especially if you are exposed to stressors."

"The hopeful message is if you engage in these healthy behaviors, you can decrease some effects that stress can have on your body," he said.

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