Can gray hair turn black again? The doctor's answer is unexpected

I believe that not many people like their gray hair. Especially many middle-aged people and some young people with premature gray hair always complain that gray hair affects their personal image and is very troubled. Even if there are only a few gray hairs on the head, they seem to be particularly eye-catching.

Copyright images in the gallery. Reprinting and using them may lead to copyright disputes.

Many people can’t help but ask, after the hair turns white, can it turn black again?

To give a simple answer, the answer is - you can get your hair back to black, for example by dyeing your hair.

But you may not be satisfied with this clever answer and want to know more about treatment methods. So today we will take a closer look at the issues of black and white hair.

How hair color changes

The color of hair is determined by the pigment in the hair, which is mainly melanin, or melanin for short. Black hair has more melanin, white hair has less or no melanin, and gray hair is somewhere in between.

Black hair (left) and white hair (right) (from reference)

The production process of melanin is like a complex production line, which is affected by various links, such as race, genetics, individual differences, disease, age, etc.

So, why does hair turn from black to white? To sum up the root cause in one sentence, it is the dysfunction and cell death of melanogenic melanocytes in the pigment unit of hair follicles.

That is, specific melanocytes malfunction or simply die, which is like a chicken that is sick or dead, so there are no eggs.

Many other cells also play an important role in this process, especially the stem cells of melanocytes, which have the ability to "create something out of nothing", that is, to differentiate and transform into new melanocytes. Due to factors such as aging, these stem cells become "lazy" and their transformation ability decreases, and white hair will become more and more. If the stem cells are completely lost, the white hair will never turn black.

Copyright images in the gallery. Reprinting and using them may lead to copyright disputes.

In addition, epithelial stem cells in the hair follicles also get involved. Their progeny cells provide a breeding ground for stem cells that cultivate melanocytes. If the progeny cells are exhausted for some reason, the hair will turn white.

In addition to the influence of stem cells, there are also quite complex mechanisms at the molecular level.

What causes hair to turn gray?

Now that we understand the basic principles of hair color change, let’s talk about why some people’s hair turns white at a young age. In fact, from the perspective of the cause, there are only two main reasons:

Physiological reasons: such as old age, family heredity;

Pathological causes: such as skin and hair diseases, drug effects.

People with gray hair can be divided into "normal gray hair" and "premature gray hair" according to their age. Asians start to have gray hair in their 30s, which is "normal gray hair". Many people have half of their hair white by the age of 50. Normal gray hair is generally a normal sign of aging. "Premature gray hair" refers to gray hair at the age of 25 or earlier, which is 10 years or even longer earlier than the normal gray hair group.

For most people (including premature graying of hair), the main reason for graying hair is physiological. Scholars once analyzed the data of 467 people with "premature graying of hair" (354 women and 113 men), ranging in age from 18 to 77 years old. The results found that:

Premature graying of hair is closely associated with family history, whether it is the father, mother, grandparents or siblings, which suggests that the power of genes is strong;

If you are iron deficient, you are more likely to have gray hair;

If you are a man, taking oral biotin supplements is more likely to cause gray hair.

In addition, the study also found that premature graying of hair has no definite correlation with obesity, alcohol consumption, coffee drinking, stress, bad mood, or immune disease.

It has to be said that this study has many counterintuitive results. For example, it is generally believed that emotional stress can cause hair to turn gray, but so far, there is no definitive research to prove that stress and gray hair have a causal relationship.

In addition, some people may be superstitious that using health products and supplementing nutrients will improve the condition of hair, but blindly and without basis using such products may be counterproductive, because as mentioned above, men are more likely to develop gray hair if they take biotin supplements orally.

Copyright images in the gallery. Reprinting and using them may lead to copyright disputes.

So, how do you tell if you have pathological gray hair?

If you are of the right age (around 30 or older), with a few grey hairs appearing occasionally, and the texture, skin texture and pigmentation on your face slowly showing up, then you basically don't have to worry about any other problems.

If a large area of ​​hair turns white in a short period of time, or is accompanied by symptoms such as hair loss and white scalp, or if there are skin and non-skin symptoms, it may be due to disease. At this time, it is recommended to see a doctor offline to see if there are other problems. The above symptoms may be manifestations of diseases such as alopecia areata (commonly known as alopecia areata), telogen effluvium, vitiligo, internal medicine diseases, and drug reactions.

How to turn white hair black?

So is there any way to turn gray hair black? There are several practical and feasible methods.

1. Hair Dyeing

Although hair dyeing is not a medical treatment, it is indeed a way to darken the hair, and it has an immediate effect. This suggestion is not a clever suggestion, but a helpless move - although scientists have discovered some promising drugs, no recognized effective darkening drug has been approved so far.

2. Remove or cut off

Plucking out white hair can theoretically remove it, and you don't have to worry about 10 growing out of it. However, this measure has the risk of damaging hair follicles and increasing the chance of infection.

Rather than yanking out the hair, it is better to cut off the gray hair at the root, because it does not damage the hair follicles. The disadvantage is that the gray hair is only a temporary relief, and it will grow back after a while.

3. Treat related diseases promptly

Some white hair is caused by diseases, such as alopecia areata and vitiligo. Then the focus of treatment should be on the original disease. After the disease is cured, the white hair will hopefully improve.

References

[1] Matamá T, Gomes AC, Cavaco-Paulo A. Hair coloration by gene regulation: Fact or fiction? Trends Biotechnol. 2015; 33(12): 707-711.

[2] The depigmentation of white hair. https://www.nccreation.ch/en/cure-of-melanin-in-an-other-solution-for-your-white-hair/

[3] Yale K, Juhasz M, Atanaskova Mesinkovska N. Medication-induced repigmentation of gray hair: a systematic review. Skin Appendage Disord. 2020; 6(1): 1-10.

[4] Feng Z, Qin Y, Jiang G. Reversing gray hair: Inspiring the development of new therapies through research on hair pigmentation and repigmentation progress. Int J Biol Sci. 2023; 19(14): 4588.

[5] Thompson KG, Marchitto MC, Ly BCK, et al. Evaluation of physiological, psychological, and lifestyle factors associated with premature hair graying. Int J Trichology. 2019; 11(4): 153.

[6] Webmd. Facts About Gray Hair. https://www.webmd.com/beauty/ss/slideshow-beauty-gray-hair-facts. Nov 15, 2021.

[7] Kumar AB, Shamim H, Nagaraju U. Premature graying of hair: Review with updates. Int J Trichology. 2018; 10(5): 198-203.

[8] Kaur K, Kaur R, Bala I. Therapeutics of premature hair graying: A long journey ahead. J Cosmet Dermatol. 2019. Epub ahead of print.

[9] Leerunyakul K, Suchonwanit P. Asian hair: A review of structures, properties, and distinctive disorders. Clin Cosmet Investig Dermatol. 2020; 13: 309-318.

Author: Tang Jiaoqing, MD, attending physician of dermatology

Review | Feng Jun, deputy chief physician of the Dermatology Department of Sinopharm Tongmei General Hospital