Is the saying that “pulling out a gray hair will lead to more of them” true? A Mainichi Shimbun reporter asked an expert studying the mechanisms of gray hair about what you should and shouldn’t do when you see graying strands in the mirror.
This reporter found a single gray hair on the top of her head, and was about to pluck it, before remembering the saying. According to Hitomi Aoki, a lecturer on regenerative medicine at Gifu University’s graduate school, hair matrix cells divide and move up the follicle, leading to hair growth. One’s hair color is determined during this process, as pigment produced by the melanocyte stem cells called melanin is passed onto the matrix cells. When the melanocyte stem cells start to die and become depleted due to aging or other factors, the lack of pigment results in white hair.
Plucking hair accelerates their growth cycle and shortens the lifespan of these melanocyte stem cells. This has led Aoki to believe that “pulling out gray hair generally works in the direction of increasing” the amount of gray hair.
Furthermore, since two to three hair strands grow from a single pore, even if one of the hairs is gray, plucking it apparently makes the other strands more likely to turn gray as well. This is because pulling out the white hair accelerates the growth cycle of the melanocyte stem cells, preventing pigment from being supplied to other stands growing from the same pore. Since plucking hair also damages the hair follicles, it is better to cut the gray hair strand with scissors or leave them as they are.
Gray hair from stress can be reversed
In addition to aging and heredity, the underlying causes of gray hair are thought to include insufficient blood flow due to stress and smoking. Studies on animals have proven that neurotransmitters released during stress, in particular, damage the melanocyte stem cells, resulting in an increase in gray hair.
When asked if, for example, black hair that turned gray can be reversed, Aoki answered, “There is a high possibility that gray hair can revert back to black.” There are reports that 20 to 30% of melanocyte stem cells remain in the hair follicles even if the hair has turned gray. If there are remaining melanocyte stem cells, stress reduction, improved blood flow and a well-balanced diet could result in the hair color being restored.
Graying of the hair is a natural phenomenon that comes with aging, but Aoki explained the significance of preventing them. She explained, “Just as hair is used in drug testing, the human body has the ability to expel harmful substances from the body by mixing them into hair pigment. Preventing gray hair is important not only for our appearance, but also for our physical health.”
