Bleaching hair is a natural and inevitable process. Fortunately, it is very rarely a symptom of an illness.
“It’s normal that you have so much white hair, you’re always stressed!”; “Do not pluck this white hair, otherwise others will grow!” White hair is still subject to many misconceptions. However, sooner or later, they lose their color, and will never find it again. Stress is often blamed. But if in some people the first white hair appears earlier than in others, it is mainly due to genetic predispositions.
So there is no point in favoring this or that diet that is supposed to postpone the deadline. “We don’t know how to delay whitening hair,” said Dr. Philippe Assouly, a dermatologist specializing in the scalp at the Sabouraud center (Saint-Louis hospital) in Paris. What caused this process?
A question of melanocytes
The color of our skin, our hair, our hair or our irises is linked to the presence of melanin, a pigment which can be brown-black or yellow-red in color. “The latter is produced by cells called melanocytes, present in each of our hair follicles”, continues the dermatologist. The hairs and hair are born in these tiny cavities – the surface of our body can count up to 5 million. Hair follicles also contain keratinocytes, cells that synthesize keratin, the main constituent of hair. As the hair grows, the melanocytes transmit melanin to the keratinocytes. The hair is therefore pigmented at the level of its root, which allows it to be colored over its entire length.
“But as they age, these melanocytes no longer transmit pigment, they are no longer functional”, describes Dr Assouly. The hair then no longer receiving melanin, they become white. And since the melanocytes cannot reactivate, the phenomenon is definitive. Except in exceptional cases: certain localized diseases of the scalp or certain treatments for serious diseases can trigger repigmentation of the hair.
A genetic predisposition
Why do some have white hair at 20 or younger, while others are spared until 50? “It is above all linked to a genetic predisposition,” says the dermatologist. So if your parents or other family members had white hair early, there is a higher probability that this is also the case for you. “The myth that when one tears off a hair, it causes the bleaching of others is therefore obviously false! It’s just that if we have white hair, the general tendency of our scalp is to fade, so others bleach. ”
Some factors could still promote premature bleaching of hair. Several studies notably question tobacco. Severe deficiencies linked to undernutrition can also lead to discoloration of the hair, “but this is not the only symptom of the deficiency, far from it, and it is temporary,” specifies Dr Assouly. Hormonal disorders, especially linked to thyroid disorders, can also play a role. “There is sometimes a diffuse whitening, distributed all over the head,” says the doctor.
Conversely, in the case of vitiligo – a disease characterized by depigmentation of the skin – the bleaching is very localized. The symptoms of this benign pathology are due to the loss of melanocytes, so discoloration affects both the skin and the hair. Another example is that of albinism. This peculiarity is due to a genetic abnormality which leads to a deficit in melanin production.
What about stress?
Legend has it that the morning of her execution, October 16, 1793, Marie-Antoinette woke up with completely white hair, even though it was colored the day before. Today, “Marie-Antoinette syndrome” is a term used to designate very rapid whitening of hair. Which is actually impossible. “It is actually alopecia areata, an autoimmune disease that can promote hair depigmentation, but above all, that more readily causes loss of pigmented hair,” corrects Dr. Assouly. Only the white hair remains in place, giving the impression that all of the hair has been bleached. “In rare cases, the triggering of this alopecia areata can be linked to stress, but this factor remains marginal.”
Aside from these exceptions, no link between stress and the appearance of white hair has ever been proven. No reason to worry, therefore, if the first gray hairs appear early.