What makes hair gray? Stuck cells that hold cancer clues too

We often talk about our hair “turning” gray. But that’s a bit of a misnomer.

If you’re naturally a blond, brunette or redhead, that color is fixed for at least the first few decades of your life. Then, as you age, your hair follicles produce less and less of the melanin that colors your hair.

So when each hair follicle goes through its natural cycle of death and regeneration, the new hair that’s produced comes in with little to no color. That’s why your hair “goes” gray as you get older.

Scientists believe the graying process is partly due to a gradual decline in the number of hair follicle stem cells that mature into melanin-producing cells — cells that also have a role in the dangerous skin cancer, melanoma.

And what they learned could have implications for both issues…

“Stuck” stem cells are key

A study in mice led by researchers at NYU Grossman School of Medicine zeroed in on these melanin-producing cells called melanocyte stem cells (McSCs).

During normal hair growth, McSCs have plasticity. This means they continually move between compartments of the developing hair follicle, where they’re exposed to different levels of protein signals that influence maturity.

The researchers found that as hair ages, sheds and grows back, increasing numbers of McSCs get “stuck” in the compartment known as the hair follicle bulge. When they remain there, they don’t mature and return to their original location in the germ compartment. That compartment is where proteins would signal the McSCs to regenerate into melanin-producing cells.

“Our study adds to our basic understanding of how melanocyte stem cells work to color hair,” says study lead investigator Dr. Qi Sun, a postdoctoral fellow at NYU Langone Health. “The newfound 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 graying of human hair by helping jammed cells to move again between developing hair follicle compartments.”

In other words, now that research has figured out what starts hair turning gray, the next step will be to find out how to stop it.

These findings may also have implications for melanoma research. Melanoma is an aggressive type of skin cancer that develops from melanocytes. One reason it’s so fierce is that, unlike other tumors, the melanocytes in melanoma have plasticity, meaning they can change easily. This makes them difficult to eradicate. The knowledge that McSCs retain greater plasticity than previously thought may play a role in future studies of melanoma.

Keeping our hair color longer

Until science can help us keep color in our locks longer, here are a few things that might help.

First, make sure you’re managing the stress in your life. Stress releases cortisol, which can impact the McSCs responsible for coloring your hair. Research has shown that stressful events can turn colored hair gray.

Also, make sure you’re getting enough B vitamins, particularly vitamin B12. Deficiency in B12 is considered a significant contributor to gray hair. Other nutrients that are key to preserving hair color include iron, zinc and vitamin D.

There are several foods you can eat that will help protect against graying hair. For instance, hummus is loaded with folate, which plays a key role in producing methionine. This amino acid is essential for hair color. Hummus is also an excellent source of copper, which supports melanin production.

Iron supports hair color by boosting ferritin levels. Dark chocolate is a good source.

Keeping your gut microbiome healthy can also help delay the graying of your hair by helping to produce biotin. A biotin deficiency can contribute to premature gray hair. Eating fermented foods like kimchi or sauerkraut helps provide your gut microbiome with helpful bacteria, as does taking a daily probiotic.

Sources:

Study Links ‘Stuck’ Stem Cells to Hair Turning Gray — NYU Langone Health

Dedifferentiation maintains melanocyte stem cells in a dynamic niche — Nature

Gray Hair and Aging: Could ‘Stuck’ Stem Cells Be to Blame? — WebMD

Why does hair turn gray? — Harvard Health Publishing

Why Hair Turns Gray — Cleveland Clinic

How to Reverse Gray Hair — Vegamour

4 Foods to Eat to Delay Gray Hair, According to a Clinical Nutritionist — Vegamour