A new study by researchers at the Columbia University Vagelos College of Physicians and Surgeons found the first quantitative evidence linking psychological stress to graying hair in people.
The findings were published in the journal eLife. While it may seem intuitive that stress can accelerate graying, the researchers were surprised to discover that hair colon can be restored when stress is eliminated, a finding that contrasts with a recent study in mice that suggested that stressed-induced gray hairs are permanent.
The study has broader significance than confirming age-old speculation about the effects of stress on hair color, said the study’s senior author Martin Picard, PhD, associate professor of behavioural medicine (in psychiatry and neurology) at Columbia University Vagelos College of Physicians and Surgeons.
“Understanding the mechanisms that allow ‘old’ gray hairs to return to their ‘young’ pigmented states could yield new clues about the malleability of human aging in general and how it is influenced by stress,” Picard said.
“Our data add to a growing body of evidence demonstrating that human aging is not a linear, fixed biological process but may, at least in part, be halted or even temporarily reversed,” Picard added.
Studying hair as an avenue to investigate aging
“Just as the rings in a tree trunk hold information about past decades in the life of a tree, our hair contains information about our biological history,” Picard said. “When hairs are still under the skin as follicles, they are subject to the influence of stress hormones and other things happening in our mind and body. Once hairs grow out of the scalp, they harden and permanently crystallize these exposures into a stable form.”
Though people have long believed that psychological stress can accelerate gray hair, scientists have debated the connection due to the lack of sensitive methods that can precisely correlate times of stress with hair pigmentation at a single-follicle level.