
Scientists believe they have now identified a key cause of gray hair. And, contrary to what your mother told you long ago, the key cause isn’t the misbehavior of children, or worrying about who they might be out with late at night. Instead, it’s primarily caused by cells that have gotten stuck in what used to be their natural cycle.
The scientific study, described in a paper in Nature, focused on melanocytes, a kind of stem cell that produces melanin, which controls hair color as well as eye and skin color. These cells are found in your hair follicles, where they await a protein signal telling them to become mature cells and produce the pigment that is your natural hair color. The melanocytes move around in there, and in different locations they get different protein signals. The study found that over time, however, more and more of the stems cells get stuck in an area called the “hair follicle bulge,” where they aren’t getting the signal to fully mature and produce color. As a result of this and other causes, you get gray hair–that is, hair without color. (Incidentally, other causes of gray hair can include stress, so maybe your mother was right after all.)
The study gives some insight into how science works, because it required the researchers to repeatedly pluck hairs from mice to artificially speed up the “stuck in the hair follicle bulge” status. Presumably, some hapless lab assistant was at work with a magnifying glass and tweezers every day for two years, to perform the minute mouse hair plucking. But their sacrifice in miniature barbering was worth it, because this discovery may allow scientists to figure out how to get the melanocytes out of the bulge and back into their normal rotation, allowing people to recover their natural hair color without resort to Grecian Formula 16.
Based on the condition of my head, I’ve got lots of melanocytes stuck in hair follicle bulges throughout the scalp territory. I hope they are enjoying themselves in there.