Hair color trends come and go, and we live in paradoxical times: when more women are embracing their natural grays, more men are dyeing their hair, and many young people are going for the gray ‘granny hair’ look. Still, for the majority of us, gray hair is something to be prevented or delayed for as long as possible.  

What Causes Hair to Turn Gray?

Hair pigment (melanin) is produced by melanocytes in the hair bulb, transferred to keratinocytes, and pushed up as the hair cells proliferate. Hair graying results from oxidation of the melanin by a natural accumulation of hydrogen peroxide (a strong oxidizing agent) in the melanocyte stem cells in the hair bulge (part of the hair follicle), causing hair to lose its color. This oxidation is the same process used to dye hair blonde, where hydrogen peroxide is used to bleach the hair’s natural pigment. The same thing occurs when hair is exposed to too much ultraviolet light from the sun. That’s why prolonged sunbathing causes the hair to become blonde.

What You Can Take to Prevent or Delay Hair Graying

Since oxidation of melanin causes hair to lose its color and turn gray, anything that slows oxidation will help the hair retain its color for longer. Good antioxidants are vitamins A, C, D and E and N-acetylcysteine, a supplement trichologists often recommend. Vitamin C, along with copper, is also crucial for melanin production.

Vitamin D acts as an antioxidant but is not directly involved with the production of melanin, but I have had several patients whose hair darkened after taking vitamin D as a supplement. This is because it facilitated the absorption of calcium, and calcium is necessary for pigment production and transfer from melanocytes in the hair bulb to keratinocytes. Other important minerals for pigmentation are iron and zinc.

Stress also causes loss of hair pigment as a result of the sympathetic nerves acting directly on the melanocyte stem cells and depleting the hair follicle of these cells, so no pigment can then be produced. Taking L-tyrosine as a supplement (and obtaining tyrosine from protein foods) not only reduces the action of the sympathetic nerves on the hair in times of stress, but also provides the precursor for melanin production. L-DOPA is produced from tyrosine as an intermediate step in pigment production and is also used as medication in Parkinson’s disease. This explains why the hair of such sufferers can darken when they are on therapy.

On a final note, when hair regrows with alopecia areata, it is often initially white before gradually returning to its normal color. This is because the white blood cells attacking the hair bulbs are thought to be attacking the melanocytes, along with other parts of the hair bulb. So if the hair grows back white, don’t despair as the normal pigment can return.

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