Q 2-7.
Why Does Hair Become Gray with Age?
Why does hair lose original color in the adult age?
Is gray hair good hair or bad hair?
Should gray hair be pulled out?
A 2-7.
Hair graying is one of the common characteristics of aging in humans. There are basic studies on this issue.
Melanocytes are situated in the hair bulb epithelium in the scalp. Melanocyte produces melanin pigmentation within keratinocytes of hair fiber.
Melanin pigmentation contains two types of melanin, the black-brown pigment (eumelanin) and the yellow-red pigment (pheomelanin). The melanin pigmentation determines the color of mammalian hair, e.g. red, brown or black hair.
These pigments are synthesized from tyrosine by the enzyme tyrosinase.
Melanocyte produces other substances too. The substances suppress growth of the diameter of hair shafts.
When melanocyte loses activity in the old age, tyrosinase activity becomes reduced or absent. Melanocyte stops producing melanin pigmentation and other substances, and the color of hair becomes gray or white.
As suppressor factors are not produced, the diameter of gray hair shafts becomes thicker than the previous hair. If you observe gray hair under a microscope, the diameter of gray hair is always thicker than that of pigmented hair.
White hair grows even faster than pigmented hair.
You would be grateful for coarse and rapidly growing hair.
You can cut the gray hair if you don’t like it. But gray hair should not be pulled out.
You only need to dye gray hair. Then, you will be able to enjoy hair thickness.
