What Causes Gray Hair?

Gray hair may be merely a cosmetic problem but it can have serious effects on an individual's self-esteem and emotional state. For many, the appearance of their first gray hairs signifies they're getting older in a very real way. In most cases, gray hair can be colored easily with hair dye to cosmetically restore the individual's natural hair color but hair dye must be touched up every few weeks. If individuals are in their forties or fifties, gray hair may seem like a natural part of getting older but even individuals in their teens and twenties can develop premature gray hair for a variety of reasons.

Vitiligo

Vitiligo is a disease that causes pigment loss in the skin and sometimes the eyes and hair. The disease causes damage or death to pigment-producing cells that produce melanin that gives hair, eyes, and skin their color. This can leave white patches of skin that may grow over time. Some patients with the disease develop hair that goes gray prematurely. Because vitiligo often causes light patches of skin that spread, some patients may develop just a section of hair that turns white or gray, but this patch may spread across the entire scalp.

This happens because hair depigmentation follows skin depigmentation as the disease progresses. Many individuals with the disease do not develop premature gray hair, however, because follicular melanocytes, or cells that produce melanin for hair, are different than melanocytes in the skin. Follicular melanocytes are not all mature cells; the hair follicles contain an immature type of melanocyte that can escape damage from the disease.

Lack Of Vitamin B12

While gray hair is usually the result of a natural aging process, hair color can be affected by diet. A lack of vitamin B12 can potentially cause graying hair along with other symptoms like lack of energy, difficulty concentrating, bleeding gums, and pale skin. A vitamin B12 deficiency is an uncommon but reversible cause of gray hair. If individuals suspect their premature grays are caused by a vitamin deficiency, consuming more foods rich in B12 can reverse the graying. Many foods offer a good source of vitamin B12, but most are animal food sources such as shellfish, salmon, tuna, lamb, beef, eggs, milk, and yogurt.

Normal Part Of Aging

As is clear at this point, for most individuals, gray hair is a normal part of aging. This happens for many reasons. As individuals age, the melanocytes in their hair follicles that produce pigment die or become inefficient. The hair follicles will slowly produce less color as individuals age. Stress can also play a role as research indicates stress hormones can promote the migration of melanin-producing cells away from the hair follicles. New research also indicates a previously unknown mechanism behind graying hair: hydrogen peroxide.

Over time, the body reduces its production of an enzyme called catalase, which typically breaks down hydrogen peroxide into oxygen and water. This leads to a buildup of hydrogen peroxide in hair follicles. This buildup disrupts production of an enzyme called tyrosinase, which produces melanin in follicular melanocyte cells. This means hydrogen peroxide in the hair follicles blocks the production of melanin and leads to hair that grows in white or gray.

Genetics And Premature Gray Hair

Premature graying is largely an issue of genetics. Several studies have found a link between genetics and premature gray hair, identifying some genes responsible for the melanin loss. The primary gene that causes gray hair was identified as IRF4, the same gene responsible for light hair in individuals of European descent. This gene is responsible for producing and regulating melanin. As hair turns gray, this gene causes even lower productions of melanin.

Researchers are still trying to identify which genes are to blame for premature graying in an individual's twenties although one thing is sure: if someone's parents or grandparents went gray prematurely, they probably will too. Along with genes, ethnicity and race play a role in how soon an individual's hair will likely turn gray. African Americans tend to notice gray hairs beginning at forty years old whereas whites notice graying around thirty-five years old.

Reduction In The Production Of Melanin

Gray hair is the result of a reduction in the production of melanin, which we know is what gives hair, skin, and eyes color. Reduced melanin production can happen for many reasons. The most common causes are genetics and normal aging, as hormone and enzyme production naturally declines with age. Certain illnesses can also impair melanin production, and these include vitamin B12 deficiency, thyroid disease, alopecia areata, tuberous sclerosis, and neurofibromatosis. Alopecia areata is a disorder that causes sudden loss of patches of hair, particularly colored hair. This can lead to seemingly sudden graying as already present gray hairs become more obvious.