Yes, we can reverse gray hair. No, we don’t know why it works.

There is so much news this year that seems to be giving us gray hair. You’re forgiven if you missed one that gives us hope that we can restore those gray hairs back to their normal color – no coloring required.

In the first published study to find evidence of “natural repigmentation,”(Opens in a new tab) Columbia University researchers set out to create a computer model showing how hair graying occurs with age and in response to stressful events. First, they identified 323 proteins that tell us if a hair was gray, white, or colored at any point in its history. They then trimmed colored and gray hair from 14 participants who listed and rated the stress levels in their lives over the past year. We know there’s a link between graying and high levels of stress; You only have to look at ex-presidents’ hair that they don’t dye(Opens in a new tab) to see this in action.

What we didn’t suspect is that the opposite could also be true; that relaxation events can restore color to these exhausted fibers. That’s what the study found when it matched the protein histories of the hair (which grows pretty reliably an inch a month) to the history of its owners: some normally colored hair had actually been gray in the past year, but went back to normal when life stress levels were low was.

“I wasn’t surprised by any of the stressors that come with going gray; I was surprised to see the power of vacationing in reversing graying,” says Ayelet Rosenberg, lead author of the study. “One participant only went on a two-week trip, and amazingly, five of his hairs regained color afterward.”

Examples of dramatic hair color reversals all over the body in the Columbia study.
Credit: Life Sciences

Before the ailing tourism industry celebrates this news, however, there’s still a lot to be said about the science of graying hair. More studies are needed to find out if this recoloring effect ever occurs beyond age 40 (the few over 40s in the Columbia study did not). However, if we can replicate these findings anytime soon – and the pandemic has given us one hell of a stressful event that we need to map onto hair around the world – the implications will be huge.

Why? Because we’re constantly being told that too much stress is a killer and that we should fight it with mindfulness, exercise, sleep, and the rest of the well-known list. But the danger feels distant because it’s within. Nobody wakes up in the morning and sees their hardened arteries staring back at them in the mirror. However, when it comes to new gray hairs, many of us seem to aim like terminators.

And just this once, human vanity might save us—because in our future world of preventive medicine, new gray hairs are worth telling your doctor about.

“Hair is unique because it’s a visible change that also indicates changes at the cellular level,” says Rosenberg. “The ideal result would be that doctors could one day use hair pigments with our method as a diagnostic tool. If someone suddenly experienced gray hair, it would make sense to look at the stress level at the appropriate point in their life.

“If you see it with your own eyes, I think people are more likely to care and maybe make a change.”

The stem cell solution

So what actually happens at the cellular level when our hair regains color? Quite simply: Stem cells vibrate in action. Stem cells, the raw material of the growing human body capable of making any type of cell needed, are increasingly used in a variety of medical therapies. We are in a golden age of stem cell research; only in the last few weeks have we learned how to eradicate HIV(Opens in a new tab)Brain tumors stop growing(Opens in a new tab)and can be injected to successfully treat heart and lung diseases(Opens in a new tab) in mice.

But hair is a relatively new focus for stem cell research, in part because we didn’t know it was powerful enough to recolor our grays. Melanocytes are the type of stem cells that live in our hair follicles. Some studies suggest that there is a limited reservoir of melanocytes up there; When they’re done, so is your hair color. But this is far from established science.

“Stem cell depletion would mean that the graying is permanent, but this has only been shown in mice,” says Rosenberg. Melanocytes could also be replenished by mysterious visitors, she adds: “Some transient stem cells could be coming in that could possibly be responsible for the repigmentation we’re seeing here.” Now say it with me: More studies needed.

Fear not, millennials in their forties on the cusp of a graying decade. Science may soon find that extreme dedication to stress reduction can reverse hair color loss at any age — something that would be far easier to prove if those Buddhist monks who love to study experimenters (whose brains seem to stay significantly younger through meditation ).(Opens in a new tab)) would just stop shaving their heads.

Or we develop new stem cell therapies to restore our melanocytes later in life. Such therapy can be abused when younger gray-haired people use it to mask the indicators of stress they should be telling their doctors about in the first place. But whatever the case, our newfound awareness of our hair’s ability to recolor itself could be a blow to the $23 billion global hair coloring industry (expected to grow to $36 billion by 2027).(Opens in a new tab) until this message came).

Meanwhile, the Columbia study is among many to blare out the same message loud and clear: We’re too stressed, and it’s not optimal for either employers or employees. Another revealing study earlier this year found that a five-hour workday is optimal for productivity(Opens in a new tab); anything longer than that, and you start burning people out in the long run. There are tradeoffs, of course; CEOs who made the switch saw a decrease in workplace culture cohesion. But the stress caused by longer days may be more important, especially when this work culture is beginning to see hair color decline as a sign of burnout.

One day your manager may examine your head for signs of stress. More than five new gray hairs and it’s time for compulsory vacation. Say hello to your melanocytes from us.