One of the most apparent signs of aging is gray hair. Understanding why it occurs could help us prevent or reverse it.
There is a huge business in hiding gray hair, but why does hair turn gray in the first place? Will science one day find a way to reverse it?
The Science Behind Gray Hair
The answer lies in our hair cells, where hair color starts and ends. Melanocytes make melanin, the cell that gives us our hair, skin, and eye color. Melissa Harris, an associate professor of biology at the University of Alabama at Birmingham, states that the sole function of these cells is to produce pigment, which they then deposit into the hair shaft as it develops.
During the anagen phase of the hair growth cycle, hair turns color. When the hair cycle starts, stem cells in the hair follicle bulb make melanocyte cells, which are color-making cells.
These melanocytes stop making color as time passes because they aren't working either. Instead of melanin, air fills the hair shaft, making it look gray, silver, or white.
As much as 99% of hair color is decided by genes; genes also significantly influence when and how we gray. Graying is also caused by environmental factors and how we live our lives.
Pigmentation loss can happen faster if you smoke, are exposed to UV rays, don't get enough nutrients, breathe dirty air, or drink too much alcohol. Some diseases, like neurofibromatosis and thyroid disease, can also make your hair turn gray before it should.
Other Reasons Why Hair Turns Gray as People Age
Your hair's color is based on the amount of melanin it has. The pigment cells in our hair shafts slowly die off as we age.
With fewer pigment cells, hair strands have less melanin and look more precise-clearer, like gray, silver, or white. As more color cells die, the hair will turn gray.
Our genes play a big role in deciding when we start to gray. You can get gray hair any age, even in high school or college. Some people's first gray hair might not appear until their 30s or 40s. People with darker hair can see their gray hair more, but lighter hair is just as likely to go gray.
As many people think, a sudden shock or trauma can't make hair gray fast. But worry can cause conditions like telogen effluvium, where hair loss speeds up and makes gray hairs stand out more.
Scientists are hopeful that they can find ways to stop hair graying. Studies suggest that hair loss may be linked to an immune response, and possible treatments could bring melanocyte-producing stem cells back to life.
Notably, some people with lung cancer had their hair turn darker again after immunotherapy treatments. A protein called PD-L1 may hold the key. This protein weakens the immune system and is more commonly found in non-active melanocyte-producing stem cells.
Reversing gray hair is still a work in progress, but the study that is being done shows promise. If scientists can figure out how hair pigmentation works, they might be able to help people keep their hair looking young. They might also learn more about age and health in general.
RELATED ARTICLE: White Hair Explained: Here's Why It Can't Go Back to Its Original Color if the Cause Is Genetic
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