Lots of great things come with age: wisdom, self-awareness, possession of some fabric softener. But some additions, like grey hair, might not be everyone’s favourite signs of growth.
If you’re one of those people, we’ve got good(ish) news. A research team from NYU Grossman School of Medicine discovered what causes greying hair – and what you might be able to do to reverse it.
They found in a recently published study that the stem cells linked to grey hairs (melanocytes) appear to work in a different way to other stem cells. The stem cell is the first to fail in humans and mice – leading to grey hairs in both.
Here’s how the cell affects your hair colour and what researchers suggest you can do about it.
What did the new study find?
Melanin is present in human and animal skin to varying degrees, and is responsible for your unique eye, hair and skin colour, according to the Cleveland Clinic. And melanocyte stem cells are responsible for its production.
The study found melanocyte stem cells (McSCs) move through your hair follicles. And these different compartments of your hair might have different proteins that kick off different developmental stages for the cell.
Instead of straightforwardly dying, like other stem cells, the study suggests that McSCs sort of toggle between life stages as they move through your hair (pretty amazing, right?).
This unique life cycle doesn’t mean the cells don’t change with age, though – or else we’d never have greys.
Instead, the McSCs tend to stay in one compartment of your hair called the hair follicle bulge when you get older.
And actually, rather than over-maturing the McSCs, this section of your hair prevents them from developing in the first place. So they remain grey and don’t develop any colour – a bit like a blank piece of paper before you print on it.
Basically, your hair grows while McSCs stay undeveloped, leading to greys.
What was that about reversing greys?
Well, put simply: reducing stress undoes grey hair, but we’re not really sure why. A 2021 study revealed that there were “striking associations” between hair colouration changes and recent reports of stress.
“When one donor reported an increase in stress, a hair lost its pigment. When the donor reported a reduction in stress, the same hair regained its pigment,” said researchers.
The transformation might not be absolute, and hair that’s on the turn – i.e. just about to turn grey, or just turned grey – seemed especially susceptible to stress-based reversal or induction.
“The model suggested that there might be a threshold for temporary greying; if hairs are about to go grey anyway, a stressful event might trigger that change earlier. And when the stressful event ends, if a hair is just above the threshold, then it could revert back to dark,” the study revealed.
Stem cell therapies, as well as de-stressing, could help to alter the McSC processes that create greys. And even better news – these findings could even help to prevent cancers.
Mayumi Ito, a professor at NYU Langone Health and an investigator for the 2023 study, told NPR: “When the stem cell regulation goes awry, we will have multiple health problems including cancers.
“The melanocyte stem cell system is advantageous to understand this broad issue in medical science, as the malfunction of the system is so visible.”
In the meantime, I’m off to take a mindfulness class.