- Gray hair can be a sign of aging.
- But research suggests that some gray hairs can go back to having color, and it could be linked to stress.
- The connection between stress and gray hair has been established in mice, too.
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Young people who develop gray hairs early in life can turn their whites and silvers back into color by de-stressing, research suggests.
In a small study, published in eLife, researchers collected hair samples from 14 participants aged nine to 65 years old with either "some grey hairs" or "two-colored hairs." They then analyzed the color of each strand and compared it to the timing of their hair growth.
The researchers found that 10 people had some gray hairs that reverted back to having color.
Participants whose gray hair reversed back to having color reported feeling more relaxed at the time their hair sample was analyzed. Meanwhile, participants whose hair changed to gray reported experiencing a stressful time in their lives, suggesting a link between stress and the graying process.
But researchers say this is only possible if you catch it early enough, and the reversal effect may not happen in old age.
"There is a window of opportunity during which graying is probably much more reversible than had been thought for a long time," study co-author Ralf Paus, a dermatologist at the University of Miami, told Scientific American.
But Paus said that, because not every gray hair strand reversed its color, these changes may only happen when the hair follicle is still malleable.
"We don't think that reducing stress in a 70-year-old who's been gray for years will darken their hair or increasing stress in a 10-year-old will be enough to tip their hair over the gray threshold," study co-author Martin Picard and a mitochondrial psychobiologist at Columbia University, told the Atlanta Journal Institution.
Gray hair occurs when the body stops making melanin-producing cells, which gives hair its color.
The findings in the new study builds on previous research about stress and gray hair, including, most recently, one in mice and another in over 1,000 young Turkish men and women.