Why Does Hair Turn Gray?

Posted by Azadeh Shirazi MD on


Gray hair is really hair with less melanin, which gives color to the skin and hair. With aging, there’s a gradual decline in the number of stem cells that mature to become melanin-producing cells. These cells may wear out, become damaged, or lose the support systems meant to keep them working. Genes are also a factor, since they help control melanin production. With fewer pigment cells, the strand of hair doesn’t have as much melanin becoming a transparent color like gray, silver, or white. 

Can I reverse gray hair? 

Possibly in the future as new studies show by stimulating stem cells back into action, pigment producing cells can be revitalized to reverse gray hairs. A recent study published in Cell Biology created a computer model of how graying happens with age and in response to stress in those under the age of 40. The results showed reversal of graying in 35 year olds in the early stages of graying, once the stress was significantly reduced. More research and data are needed to explore the mechanism behind the repigmentation, but this reverse gray phenomenon is unlikely in those over 40.

What are other factors that cause gray hair, besides aging? 

Aside from natural aging, other reasons for gray hair are smoking, stress, vitamin B12 deficiency, thyroid disease, and autoimmune skin conditions like alopecia aerate or vitiligo where the immune cells destroy pigment producing cells or hair follicles.

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  • I found this post interesting, I have had gray hair since I was 24

    Karina Sandoval on

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Dr. Azadeh Shirazi, MD is a Board-Certified Dermatologist.

Specializing in medical, surgical, and cosmetic dermatology, Dr. Shirazi received her undergraduate and medical degrees from the University Of Kentucky College of Medicine. After doing a Research Fellowship at Harvard Medical School at the Wellman Center for Photomedicine, she completed her residency training in Dermatology and Cutaneous Surgery at the prestigious Mayo Clinic in addition to completing her training in dermatology and cosmetic surgery at the University of California San Diego.

She has received multiple research scholarships from iconic institutions including Harvard University and the University Of Texas Southwestern Medical Center and has several peer-reviewed publications to her name.