Stress can make your hair turn grey but good news, it’s reversible

The adage of stress turning your hair grey may ring true scientifically, but new research suggests that it can be reversed.

2020 might be the year of the Grey Hair. We’ve collectively experienced more stress as a modern species than, perhaps, ever in the past year and a half, and if you’ve noticed a few extra pale strands atop your crown, you’re not alone.

Stress has indeed been shown to increase premature ageing by affecting the stem cells responsible for regenerating hair pigment, but until now it was thought that the damage caused was permanent.

A newer study by researchers at Columbia University Vagelos College of Physicians and Surgeons has produced the first qualitative evidence that stress does cause your hair to turn prematurely grey, but it can go back to its original colour.

“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,” says Dr Martin Picard, associate professor of Behavioral Medicine at Columbia University.

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Scientists examined a small group of 14 participants who were asked to rate their stress each week in a ‘stress diary’ and compared this with the colour data from their hair. Strong correlations were drawn between greying and stressful periods, though the shifts in hair colour were often subtle.

“If you use your eyes to look at a hair, it will seem like it’s the same colour throughout unless there is a major transition,” Picard says.

“Under a high-resolution scanner, you see small, subtle variations in colour, and that’s what we’re measuring.”

What struck researchers most, however, was that when one participant when on holiday, five hairs on their head “reverted back to dark during that vacation, synchronised in time.”

A previous study from 2020 showed that stress-related greying in mice was irreversible as it was caused by the loss of stem cells in hair follicles.

However, this new study has suggested the process is different in humans.

“Contrary to mice where this process appears to be irreversible at the single hair follicle level, our data demonstrates that human hair greying is, at least under some circumstances, reversible,” the study said.

It doesn’t mean that all human greying is reversible, though.

“Based on our mathematical modeling, we think hair needs to reach a threshold before it turns grey,” Picard says.

“In middle age, when the hair is near that threshold because of biological age and other factors, stress will push it over the threshold, and it transitions to grey.”

He adds: “But we don’t think that reducing stress in a 70-year-old who’s been grey for years will darken their hair or increasing stress in a 10-year-old will be enough to tip their hair over the grey threshold.”