IntroductionAt one point or the other in our lives, we spot our first gray hair. Some of us spot it during their teen years, some of us in our thirties and the remaining rest are lucky enough to spot it after 50 and not go through the trauma of premature graying of hair. Different people have a different hair color. Some of us have dark black, whereas others have different shades like medium brown, light brown, blonde, red etc. However, in the end, all these different shades will turn into a gray or white color. Premature graying of hair is due to many intrinsic and extrinsic causes. Hair that changes its color to gray or white with age is because of the death of melanocytes which are melanin-producing cells. Below the causes are mentioned which turn a natural shade of hair to gray or white as age advances.
How hair gets its colorEach hair is made up of two parts. One is a shaft and the other part is root. The shaft is the visible part which we see growing out of the scalp. Root portion remains under the scalp and thus not visible to us and it keeps the hair anchored. Root is surrounded by hair follicle which is nothing but a tube of tissue present under the skin. A hair follicle contains a certain number of pigment cells at its base called as melanocytes which are known to produce melanin. When hair is formed, melanocytes inject melanin pigment into hair cells which contain keratin. They are called as keratinocytes and are located adjacent to melanocytes. This keratin is a kind of protein that makes our skin, nails, and hair. This melanin itself is responsible to give growing shaft portion of hair its color which can be black, brown, gray, red, blonde etc. Melanin is the pigment which gives color to our eyes and skin. This chemical itself is responsible to determine how dark or light color our hair will be. Hair follicles start developing in the uterus itself. These pigment-producing melanocytes migrate into the hair bulb when hair follicles start developing in the uterus.
Melanin pigmentsMelanin comes in two different groups. One is a light pigment and another one is dark pigment. Or else can also be described as eumelanin and pheomelanin. Eumelanins has brown and black pigments and pheomelanin have red and yellow pigments. How much of the two varieties go into every single strand of hair and the type of mix that gets created determine the color. Hair gets its natural shade based on the variation in the ratio of these two pigments of melanin. The color of hair also varies depending on which part of the body it is growing. We can usually see that our eyelashes are quite dark when compared with rest of the hair on our body. The reason is that eyelashes have the highest level of eumelanin pigment in it. The hair on scalp, underarms and beard hair all have pheomelanin and thus they are lighter when compared with pubic hair.
How hair turns gray or whiteWhen we start aging, the number of pigment cells in our hair follicle decreases and as a result melanin too decreases. This is why shaft portion of hair will turn out into more transparent colors like silver, gray, white etc. Melanin production stops or slows down in early age then we may experience premature graying of hair. Melanin production usually slows down or stops if melanin producing melanocyte stem cells undergo apoptosis. It is a process of programmed cell death. Some scientists also believe that hydrogen peroxide which is naturally produced in the hair gets accumulated and blocks the melanin which in turn results in graying of hair.
The growth of hair takes place in the cycle. Melanin production too follows the rhythm of the hair cycle. Its production turns on and off in a rhythmic manner. When the hair cycle ends, melanin production turns off and when another hair cycle begins, melanin production should turn on. In case, if it does not turn on then hair turns gray. Melanocytes which are responsible for producing melanin may get damaged and die at the end of the hair cycle. This is a very major cause of hair turning gray in color. At the top portion of the hair follicle, there is melanocyte stem cell reservoir. If this reservoir has enough to replenish the bulb then melanin production does not pause and hair does not turn gray. However, if the reservoir is empty then hair turns gray. Reduction in melanin pigment causes gray hair. White hair results when there is no melanin pigment at all. Melanin is also responsible for keeping moisture in the hair. When melanin production decreases, we can notice our hair losing its smooth texture and becoming brittle and less bouncy.
The incidence rate of grayingIt is usually seen that after 30, chances of gray hair increases by 10-20% with each passing decade. At age 50, it is predicted that there are 50% chances; usually, of 50% of hair to turn into gray. In general, it is seen that men, when compared to women, have more gray hair. With age, it is a very definite thing for us to see our hair changing color more and more in number. It no way means that we are suffering from any disease or illness. It is an age-related phenomenon and quite natural. Even in those individuals who spot premature graying of hair do not have to worry a lot as graying is not always associated with health troubles. Only in certain cases, graying means the presence of underlying disease. In most of the cases, it has got nothing to do with any illness related to body or mind.
Death of melanocytesMelanocytes may get damaged due to disease and even due to environmental exposures. Autoimmune diseases, thyroid diseases and heart diseases all can accelerate graying of hair. Even smoking accelerates graying. Improper nutrition in the daily diet is another factor. However, no evidence is found between chronic stress and graying of hair. Extrinsic factors like climate, pollutants, exposure to chemicals and toxins can also be potential causes. At what age, our hair is going to grow gray depends on genetic factor. We can even see some individuals who do not show gray hair or even if they are present then they are very few in number despite their old age. This is all because of the influence of genetic factor as well as because of the way they have been keeping themselves healthy.
High estrogen and progesterone levels which are usually seen during pregnancy are responsible to bring change in the color of hair and darken the light shades. Melanocyte-stimulating hormone can also do the same thing. Drugs which are given during epileptic conditions can darken hair while those given to prevent malaria can lighten it. Premature graying of hair is seen in certain syndromes like Werner syndrome, Hutchinson's-progeria, Down syndrome and even in individuals suffering from pernicious anemia. Know more about Reasons for premature graying of hair and follow Home remedies to reverse it. Stress is usually considered to be responsible for graying of hair. Stress can trigger hair fall at three time's faster pace than normal. If an individual is middle-aged and stress is causing more hair fall then it is seen that hair regenerates back more quickly. It is very much possible that shaft of these hair follicles will have gray color instead of original shades.
ConclusionWe all are born with different shades of hair which can be dark black, brown, red, blonde etc. As our age advances, we can spot one or two gray hair and soon their number increases. By the time we hit 50, there are 50% chances that almost 50% of our hair will turn white in color. This is the case with most of us, excluding some who face premature graying of hair which can be due to illness, extrinsic causes like exposure to chemicals and toxins or may be due to poor nutrition. Melanocytes are the cells which are present at the base of the hair follicle and are responsible for the production of a chemical which is known as melanin. When melanin production is enough then our hair enjoys its natural shade. However, sometimes these melanocytes get damaged and there is no scope for their repair. Once melanin reservoir is exhausted, hair follicle starts growing gray. If little melanin is present then it turns gray and if melanin gets completely exhausted then the hair turns completely white. The genetic factor is very much responsible for our gray hair. We too will start graying our hair at the same age as our parents. In short, damage caused to melanin-producing cells is the main cause of our hair to turn gray.