Legend has it that Marie Antoinette saw her hair turn gray overnight shortly before her beheading in 1791. Although the legend is inaccurate, because the hair that has already grown from the follicle does not change color, a new study by Columbia University researchers Vagelos College of Physicians and Surgeons is the first to offer quantitative evidence linking psychological stress to gray hair in people.
And while it may seem intuitive that stress can accelerate graying, the researchers were surprised to find that hair color can be restored when stress is eliminated, a finding that contrasts with a recent study in mice that suggested that stress-induced gray hair is permanent.
The study, published on June 22 on eLife, has a broader meaning than confirming ancient speculations on the effects of stress on hair color, says senior study author Martin Picard, PhD, associate professor of behavioral medicine in psychiatry and neurology, at Columbia University Vagelos College of Physicians and Surgeons.
“Understanding the mechanisms that allow old gray hair to return to its young pigmented state could provide new clues to the malleability of human aging in general and how it is affected by stress. Our data add to a growing body of evidence showing that human aging is not a linear and fixed biological process, but can, at least in part, be interrupted or even temporarily reversed “ says Picard.
Studying hair as a way to investigate aging “Just as the rings in a tree trunk contain information about the past decades in the life of a tree, our hair contains information about our biological history”, says Picard.
“When the hairs are still under the skin as follicles, they are subject to the influence of stress hormones and other things that happen in our mind and body. Once the hairs grow from the scalp, these exposures permanently harden and crystallize into a stable form. “
Although people have long believed that psychological stress can accelerate the appearance of gray hair, scientists have debated the connection due to the lack of sensitive methods that can accurately correlate stress times with hair pigmentation at the level of a single follicle.