Why is your hair turning white at such a young age?

Author: Ma Xiaoshu (Center for Excellence in Molecular Plant Sciences/Institute of Plant Physiology and Ecology, Chinese Academy of Sciences)

The article comes from the Science Academy official account (ID: kexuedayuan)

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Gray hair is not exclusive to middle-aged and elderly people. Many young men and women in love also have this worry. As the saying goes, "One night of longing, one night of sorrow, one night of black hair turns to white hair", such as Lian Nishang in "The Legend of the White-Haired Witch"... (Of course, there are also many single dogs with "gray hair", where can they go to seek justice?!)

White-haired witch Lian Nishang (picture from the Internet)

So, what exactly causes hair to turn white? Today we will talk to you about the love-hate relationship with white hair.

Without melanin, hair turns white

Simply put, the reason for the formation of white hair is that the melanocytes at the hair roots stop producing melanosomes.

The part of the hair that is exposed to the skin surface is called the hair shaft, and the part inside the hair follicle is called the hair root. At the lower end of the hair root, there is an onion-like swelling, which is the hair bulb. The hair papilla is the part of the hair bulb that is concave inward at the base.

Under normal circumstances, the hair papilla contains abundant blood vessels, which provide sufficient nutrition for the hair papilla and hair bulb, and melanin particles are synthesized smoothly. When the formation of melanin particles in the hair papilla and hair bulb is blocked, or when they are formed but cannot be transported to the hair due to some factors, the melanin particles in the hair medulla and cortex will decrease and disappear, and eventually white hair will appear.

Schematic diagram of hair follicle structure (picture from the Internet)

Is there any scientific reason for “turning hair grey overnight”?

Scientific research shows that the causes of gray hair are divided into congenital and acquired. Congenital gray hair is often related to family inheritance, and is divided into disease-related genetic diseases and non-disease-related genetic diseases. Acquired gray hair is mainly related to external stimuli.

Disease genetic disease:

For example, vitiligo, which is present from birth, is a genetic disease that causes a triangular shape of white hair on the forehead, accompanied by white skin changes.

White spot disease (picture from the Internet)

Even more serious is albinism, in which the skin and hair of the entire body are white.

Albinism (picture from the Internet)

2. Non-disease genetic diseases:

There is also a type of inheritance that is non-disease related. Some people have gray hair when they are in their teens, which is what we often call "premature graying of hair."

The above-mentioned gray hair phenomena cannot be cured by medicine.

3. Acquired non-disease-related gray hair

Acquired non-disease-related gray hair, which is the common gray hair we see, is related to factors such as aging, malnutrition, unbalanced diet, lack of trace elements, sun exposure, smoking, alcoholism, and lack of sleep.

As we age, poor health will lead to the formation of gray hair. In addition, sub-health conditions such as tension and stress are also one of the important factors that cause gray hair in young people. In literary works, there are a lot of descriptions of "white hair overnight", which is an exaggeration based on this point. For example, the legend of Wu Zixu passing Zhaoguan, in extreme tension and anxiety, his hair turned completely white overnight.

Is it true that “pull out one grey hair and ten will grow back”?

Under normal circumstances, the number of scalp hairs is determined at birth, and the average person has about 90,000 to 100,000 hairs. As we age, the number of hair follicles decreases, with the hair density of newborns being 1135/cm2, teenagers being 615/cm2, middle-aged people being 485/cm2, and elderly people being only 435/cm2. These differences can be seen with the naked eye.

The hair growth cycle is divided into the growth phase, regression phase and resting phase. The average growth phase of hair is 3 years, the regression phase is 3 weeks and the resting phase is 3 months. Among them, 85%-90% of hair is in the growth phase. During puberty, sex hormones begin to be secreted, and androgens promote the thickening of beard, armpit and pubic hair, so it appears thicker and more, but the number remains the same.

Hair growth cycle (picture from the Internet)

Therefore, pulling out white hair will only shorten the life of the white hair and damage the hair root. If you pull out too much hair when your scalp is unhealthy, it may also cause folliculitis. There is no difference between white hair and black hair in essence. If it is true that "pulling one hair will make ten grow", then those who suffer from hair loss will be very happy.

To sum up, the saying “pull out one hair and ten will grow” has no scientific basis.

If you don’t want to have gray hair, try the following four points

1: Don’t stay up late!!! Don’t stay up late!!! Don’t stay up late!!! I’ll say this three times! Sufficient sleep can promote the normal metabolism of hair and skin, and night is the best time for their metabolism.

2: Hair dyeing and perming can cause damage to the hair. It is recommended that the interval between dyeing and perming should be between three to six months.

3. In terms of diet, you should consume more foods rich in vitamin E, B vitamins, niacin, iron and copper that promote metabolism, such as black fungus, black sesame, soybeans, sesame paste, etc.

4. Wash and comb your hair properly: Do not use strong degreasing or alkaline shampoos, because these shampoos have strong degreasing and dehydrating properties, which can easily make the hair dry and the scalp necrotic. Wash your hair 2-3 times a week. The water temperature does not need to be too high when washing your hair, close to body temperature. Frequent combing of hair is also a physical massage method, which can accelerate the blood circulation of the hair follicles, improve the nutrition of the pigment cells in the hair bulb, and facilitate the secretion of melanin.

Of course, there is a kind of happiness of white hair, that is "I wish to win the heart of one person and stay together until old age". On this Chinese Valentine's Day, Dayuaner wishes couples to love each other and grow old together!

References

[1] Qian Zheng. Why do hair turn gray? Cellular DNA damage cannot be repaired [N]. Xinhua Daily Telegraph, 2009-06-17(007).

[2] Guo Xuguang. What is the cause of gray hair in teenagers? [N]. Shanghai Journal of Traditional Chinese Medicine, 2013-04-26(002).

[3] Xishu Bu Lao Weng. Why do we have white hair? [J]. Quality Education Expo, 2007(19):34.