Why does hair turn gray? Usually this phenomenon is explained by heredity, gene background. It can also be explained by belonging to a particular nation. Europeans turn gray more often than the Negroid race, and the Indians turn gray only by the age of 70-75. This explains a few things, but there is more to it.
Doctors attribute early graying of hair to stress and a weak nervous system. The causes of gray hair can be impaired metabolism, impaired functioning of the thyroid gland, problems in the reproductive system. Last but not least, bad ecology (if you live in unfavorable conditions all the time), unhealthy diet, smoking and alcohol and drug abuse.
All these reasons affect the entire body as a whole. Hair turns gray early because the body lacks tyrosine (a substance in proteins), copper and calcium.
So, according to doctors, hair color directly depends on the state of the body as a whole.
Melanin (the pigment responsible for hair color) is formed at the root of the hair, the presence or absence of gray hair depends on its quality and quantity. Scientists have studied human stem cells and found that if the body lacks them, the hair becomes gray. The loss of pigment starts from the part of the hair that is closer to the root.
The cells responsible for the color of the skin and hair combine with the cells that form the hair. Thus, the color of the hair appears. These cells are renewed with stem cells. If there is a shortage of stem cells in the body, then the renewal process is disrupted and the hair turns gray.
In addition, human hair cells produce tiny particles of hydrogen peroxide, and the older a person gets, the more it is released. Thus, the hair is discolored from the inside out and turns gray and then completely white. Experts made this discovery by studying the cell culture of hair follicles. It was found that the accumulation of hydrogen peroxide is caused by the contraction of the enzyme that promotes the breakdown of hydrogen peroxide into water and oxygen.
Interestingly, by the age of 40, 60% of the world's population already has a genetic melanin deficiency. By the age of 50, this number rises to 86%. As a rule, brunettes turn gray first, then red and light brown colors. Blondes are the last to turn gray.