Pigmentation in any part of our body, including the hair, is determined by a biological pigment called melanin. Its varied concentration in different cells produces different shades of skin and hair color. This variety is a result of the fact that melanin exists in two forms, namely eumelanin and pheomelanin.
Eumelanin or true melanin imparts a brown to black color, whereas pheomelanin produces a range of yellow to red color. The most natural hair colors are brown, black, red, and blonde.
These colors depend on the ratio of eumelanin to pheomelanin, i.e., the concentration of eumelanin is more than that of pheomelanin in case of brown or black hair, whereas it is opposite in case of red, auburn, or blonde hair.
Hair color also depends on the ethnicity of the individual. People of Asian and African origin usually have dark brown or black hair, while Caucasians can have blonde, brown, red, and auburn hair.
However, levels of these pigments do not stay constant throughout one's lifetime (with regards to hair color). The change in their levels induces a change in the overall color of the hair. Each strand of hair is made up of two parts: the follicle and the shaft.
The follicle is the part that basically generates the hair strand, and is responsible for its color, texture, and growth. The rest of the hair is called the shaft. Since the follicle is responsible for hair color, these two pigments are present in this structure.
As the follicle ages, its capacity to produce the two pigments properly diminishes. This causes a reduction of pigment in the hair strand, till ultimately no pigment is produced, causing the hair to turn white. The age at which hair starts turning white is also affected by the individual's ethnicity, to a certain extent.
Usually, it has been observed that Asian people experience graying in their late thirties, while white people can begin to gray in their mid-thirties. On the other hand, African people may not experience graying till their mid-forties.
However, the premature whitening of hair may be indicative of underlying health conditions or other harmful external characters, like exposure to radiation or toxic waste, use of harmful chemicals, or the presence of excessive pollutant in the environment. Here is a list of possible internal, biological factors that bring about the whitening of hair.
Causes of White Hair
Melanin is produced by the stem cells known as melanocytes, that are located at the base of the hair follicle. When these cells starts to die while aging, the production of melanin gets impaired. However, the age at which a person would experience graying depends on genetics, as it is an inheritable trait.
Premature graying of hair depends on hereditary factors. If one or both parents have experienced premature white or gray hair, you are also likely to face this problem at a young age.
Many times, some individuals are born with white hair due to genetic predispositions and certain anomalies. In the genetic abnormality called albinism, one is born with white or blonde hair, due to the presence of very little pigment in hair.
In such a condition, taking vitamin B12 supplements or including foods rich in this vitamin can prevent further graying of hair.
Thyroid disorders like, hypothyroidism and hyperthyroidism can also manifest in premature graying, along with many other symptoms. The hair can become very dry and brittle due to thyroid problems, and people can experience significant hair loss due to an overactive or under active thyroid gland.
Vitiligo is a condition characterized by the destruction of the melanin-producing cells, which can be caused by autoimmune, genetic, as well as some environmental factors. The destruction of the melanin producing cells, called melanocytes, causes the development of white patches in the skin and hair.
Individuals going through a prolonged period of mental stress, often witness premature hair graying over a period of time. This leads to the mistaken conclusion that stress is the cause of white hair, when in fact, it is just one affecting factor.
It is an autoimmune condition where the antibodies produced by the immune system attack some specific stomach cells that impair the absorption of vitamin B12. Deficiency of vitamin B12 causes anemia or deficiency of red blood cells, which can present many symptoms, including premature white hair.
Apart from the aforementioned causes, graying of hair can be associated with many other factors like excessive use of harsh chemicals on hair, pollution, and smoking. Therefore, it is very important to determine and address the underlying causes, in order to prevent premature graying.
At the same time, following a balanced diet, regular exercising to manage stress levels, proper hair care, and avoiding habits such as smoking can prove beneficial for controlling the condition.