Why do we get gray hair?

Have you ever heard the phrase ‘fifty percent of people are fifty percent gray by the age of fifty’1? Turns out this rule of thumb might be a myth.

A few years ago, several scientists tested this idea in a study that consisted of 4,192 healthy individuals2. Using categories like age, gender, ethnicity and geographic origin, patterns amongst gray haired individuals emerged2. As we could have guessed, these scientists found that the number of gray haired individuals increased with age2. However, it was also discovered that only about  23% of these individuals were 50 percent gray at age 502. This is good news for those of us who are closer to 50 then we’d like to admit. But is it possible to avoid graying altogether?

To avoid graying, limit your risk factors. Some risk factors for premature graying (graying before the age of 30) can include weight, genetics, stress, alcohol consumption and UV radiation3. Smoking can also be a contributing factor. Toxins found in cigarettes can cause damage to hair follicles and can alter your hair cycle2.

There are some risk factors however that may not be avoidable such as ethnicity. For example, in the study discussed above, the lowest frequency of graying was found in Sub-Saharan African and African American individuals2. Autoimmune disorders (e.g., vitiligo, pernicious anemia etc.) can also cause graying. In these disorders, actively-growing pigmented hairs are attacked by the body4. Increased amount of gray hairs and hair loss can be the direct result of these autoimmune conditions.

Can we do anything to help cover the gray? Since gray hairs are missing their key color ingredient (melanin), hair coloring can be an effective way of dealing with grays5. Permanent dyes are suggested as they are the most effective hair coloring option for gray hair. Purchasing a hair system is an alternative option to help camouflage those grays.

 Article by: Sarah Versteeg MSc, Mediprobe Research Inc. 


  1. Keogh EV, Walsh RJ. Rate of greying of human hair. Nature. 1965 Aug 21;207(999):877–8.
  2. Trüeb RM. Aging of hair. J Cosmet Dermatol. 2005 Jun;4(2):60–72.
  3. Shin H, Ryu HH, Yoon J, Jo S, Jang S, Choi M, et al. Association of premature hair graying with family history, smoking, and obesity: a cross-sectional study. J Am Acad Dermatol. 2015 Feb;72(2):321–7.
  4. Paus R, Slominski A, Czarnetzki BM. Is alopecia areata an autoimmune-response against melanogenesis-related proteins, exposed by abnormal MHC class I expression in the anagen hair bulb? Yale J Biol Med. 1993 Dec;66(6):541–54.
  5. Tobin DJ, Paus R. Graying: gerontobiology of the hair follicle pigmentary unit. Exp Gerontol. 2001 Jan;36(1):29–54.

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