Could Grey Hair Soon Be A Thing Of The Past?

Scientists at New York University may have figured out another reason hair turns grey as we age, and they have hope we could one day reverse the cycle.

Hair color is way more complicated than most of us might expect (consider yourself warned!). It is largely determined by special cells called melanocytes, the same type of cells that determine skin color by releasing melanin. Melanocyte stem cells (McSCs) in hair have the unique ability to move back and forth between sections of a hair follicle, called growth compartments, and through different stages of cell maturity. But as hair follicles age, those stem cells lose the ability to transfer between compartments, turning you into a silver fox, the new study finds.

The study, published in the journal Nature and led by NYU Langone Health postdoctoral fellow Qi Sun, determined that as McSCs move through growth compartments, they receive slightly different protein signals in each one. The variations in each signal allow the McSCs to move back and forth through different stages of maturity; mature cells release melanin, giving your hair its color.

As we shed hair and new strands form in the follicles, McSCs are more likely to become stuck in one particular compartment: the hair follicle bulge. Once these stem cells are stuck in the hair follicle bulge, the process of greying begins because the McSCs aren’t receiving protein signals telling them to release melanin, and they cannot pass into other compartments where those protein signals are released. No protein signals mean no melanin, so your hair continues to grow as it always has, just without the color you had before.

By strategically plucking hair from black mice over the course of two years, Qi Sun’s research team was able to create salt and pepper patterns in the animals' coats. They found that in unplucked hairs, around 15% of McSCs were stuck in the follicle bulge, but the percentage was closer to 50% in hairs that had been plucked, modelling grey hairs in humans. Got it?

For those that were lost at “melanocyte stem cells, here’s your bottom line: These findings suggest there may be a way to reverse the process of going grey. “The newfound mechanisms raise the possibility that the same fixed-positioning of melanocyte stem cells may exist in humans,” explained Qi Sun in a statement. “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.”

The study wasn’t just a vanity project. These findings put researchers one step closer to curing or preventing certain types of cancer, such as melanoma, the most dangerous form of skin cancer, according to NYU professor and study co-author Dr. Mayumi Ito.

“We are interested in how stem cells residing in our body are regulated to properly maintain our body and how they can reform the tissues when they are lost by injuries," Ito told NPR. "When the stem cell regulation goes awry, we will have multiple health problems, including cancers," she said. "The melanocyte stem cell system is advantageous to understand this broad issue in medical science, as the malfunction of the system is so visible."