Why hair turns grey, finally explained

Author: Editors Desk Source: News Corp Australia Network:

April 23, 2023 at 08:57

It’s a dreaded inevitability with age, but scientists say they have figured out what causes our hair to turn grey — and potentially how to stop it.

Researchers at New York University have unlocked fresh evidence as to why human hair loses its natural colour over time — which could help prevent people from greying.

The new study, conducted using mice and published in Nature, a peer-reviewed journal, closely examined the melanocyte stem cells (McSCs) known to control hair colour, the New York Post reports.

Earlier in life, these cells can be remarkably dynamic, but with age, as hair is lost and regrown, the McSCs tend to slow down, getting trapped in what’s known as the hair follicle bulge, meaning they don’t get a chance to finish the job they were created to do.

Finding a way to get them moving again, which appears to be entirely possible, could mean the end of grey hair — not just in mice, but in people too, according to the team at NYU’s Grossman School of Medicine.

The report explains why hair loses its natural colour and fades to grey as we age.

“(This) adds to our basic understanding of how melanocyte stem cells work to colour hair,” said study lead Qi Sun, PhD, a postdoctoral fellow at NYU Langone Health.

“The new-found mechanisms raise the possibility that the same fixed positioning of melanocyte stem cells may exist in humans.

“If so, it presents a potential pathway for reversing or preventing the greying of human hair by helping jammed cells to move again between developing hair follicle compartments.”

During the study, lab mice that had their hair “physically aged” by plucking and forced regrowth were observed to have a 15 per cent higher concentration of McSCs stuck in that follicle bulge before the hairs were pulled.

Celebrities like Jamie Lee Curtis have embraced grey hair, but scientists are looking at how to stop grey hair from developing. Picture: Angela Weiss/AFP

After the intervention, the percentage of hairs that no longer had pigment generating abilities rose to nearly 50 per cent.

With the greater understanding of the stalled-out cells and their probable responsibility for loss of hair colour, researchers are now focused on how to get the McSCs back on track.

According to lead researcher Professor Mayumi Ito, PhD, the task is “to investigate means of restoring motility of McSCs or of physically moving them back to their germ compartment, where they can produce pigment”.

In other words, don’t toss the hair dye just yet.

This article originally appeared on the New York Post and was reproduced with permission