Here's a question that we, from the early years onwards, have asked ourselves at least once in our lives: why does hair turn gray with age? A group of researchers from NYU Grossman School of Medicine has just discovered that the root cause is trapped stem cells.
This is a development that could lead to new methods to naturally combat graying of hair.
Gray hair: melanocytes are at the root of the problem
It all starts with a type of stem cell called melanocyte, or McSC. These cells are responsible for the production of melanin, the pigment that gives color to our skin, eyes and hair.
Previous studies (the best known this is it, from 2020) McSCs are found in hair follicles and receive a protein signal that tells them when to become mature cells. When they are ripe, they release the pigment that determines the color of the hair: the result? Gray hair.
To be more precise
In the study, published in the journal Nature (I link it here), the researchers found that McSCs move between different microscopic “rooms” within the hair follicle. Each of these rooms can provide a slightly different protein signal, allowing the cell to oscillate between different levels of maturity.
Age, stress and other factors, however, cause McSCs to tend to accumulate in a specific "room" called the bulb of the follicle.
In summary: the follicle bulb does not send the McSC cells the signal to mature, nor does it send them back into a room that would. This “traffic jam” allows the hair to continue growing, but without receiving the necessary pigmentation. This is why hair turns gray.
The good news
I have two of them. The first good news is that this research could lead to a cure for gray hair: by moving the McSCs to the right "room" inside the follicle, it will be possible to avoid the problem.
The second: Understanding how stem cells are regulated in our bodies is critical to understanding how to prevent health problems, including cancers.
In other words: whether they are gray or of another colour, the best thing is that in the future they will be able to grow on the heads of healthier people.
