The phenomenon arises naturally around 30/40 years, due to the physiological aging of the cells that give hair color, i melanocytes (the same ones responsible for the color of the skin, that of the moles and the tan), which at some point in life, and for very different reasons, they stop producing melanin, the pigment whose deficiency changes the hair color, whatever the initial one, from pearl gray to the whiteness of white. The canizia, however, can also be early, and interest young people among the 20 and 25 years old, if not before, and in these cases it is mainly genetic factors, since these people have them dna of a gene that “decides” even before physiological maturity, to no longer produce the melanin that colors the hair, and it is not said that this early graying has a direct descent from the parents, because it may have been inherited by some ancestor of which it is difficult to recover memory.
Between pathological causes some diseases such as lpernicious anemia, L’ hypothyroidism, homocystinuria, vitiligo, i low levels of sideremia and malnutrition, but the most frequent cause is “oxidative stress of melanocytes“, always on the basis of a genetic predisposition, and in the hair follicles of these white hair there are high levels of Oxygen Peroxide, the substance similar to hydrogen peroxide commonly used to lighten the hair, which favors the appearance of microscopic bubbles of air between the cells that compose them, disintegrating the original pigment that causes them to turn prematurely white along the entire stem, without any possibility of being able to defend themselves immunologically from this oxidative insult.
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In any case, there is no need to worry, because early white hair in this case is not a symptom of disease or aging of the person, but it must be accepted that, whatever the cause, they will never return to the color of the first, since, once the graying process is triggered, there is no miraculous, therapeutic or pharmacological remedy, to regrow that hair of its natural color, as it is its hair follicle, i.e. its root, that is no longer able to produce melanin , so when it returns it will always be white.
IN HISTORY – Canizia however, although it is generally a physiological process that depends on age, genetic or constitutional reasons, is always more often anticipated and caused by a strong stress, be it physical or emotional, from a great fright from a deep distress or from a terrible shock, such as that, for example, suffered by Marie Antoinette, whose long hair turned white in one night when she was arrested and locked up in solitary confinement during the French Revolution, or like the candid breeze on Aldo’s hair Moro, also appeared in a few days of acute stress. But how is it possible that fear or pain, two impalpable feelings like air, which certainly influence psychologically, are able to suddenly turn white hair? For the first time, a study by Harvard University, published in the journal Nature, has established the link between the shock suffered by the nervous system and the stem cells that regenerate pigments, highlighting that under stress our brain activates the release of large quantities of noradrenaline, the neurotransmitter that allows us to act quickly and forcefully in the face of a dangerous situation, and this substance, however, is absorbed in large quantities also by the stem cells that regenerate the pigment responsible for the color of the hair, promoting its rapid reduction with the disappearance of the coloration. This research also reveals the speed with which the pigment regenerating stem cells, which are located deep in the hair bulb, are lost and destroyed during emotional shock, because their exhaustion occurs in a time that varies from a few hours to a few days, and it is emphasized that once they are gone, it is no longer possible to regenerate them.
These results also confirm how stress affects not only the hair, whitening the hair, but many other tissues and organs of our body, which, dominated by excessive physical and psychological fatigue, can no longer block its harmful effects. . Millions of people around the world have experienced early graying from stress, which can also occur on pubic hair and in all other hair districts, but never before has the mechanism by which shock could lead in a few hours been scientifically demonstrated or in a few days to the exhaustion and death of the stem cells of the hair bulb, with the permanent damage that derives from it. However, only the color of the hair remains to be affected, because that hair, even if white, is healthy in its structure and function and will continue to grow regularly, without ever changing its new “senile” shade.
Alopecia – Stress, in addition to having a key role in the appearance of canizia, can also be the cause of alopecia or widespread hair loss, as occurs, for example, in times of nervous breakdown, in cases of depression or food deficiencies, but all lost or fallen hair, if and when they start growing again, will always be in a different color from the original one, that is, they will be inexorably silvery. However, one should not be afraid of the sudden appearance of white hair at an early age, even if observing a white lock that blooms on the hair from night to morning is always a shock, because the positive side of the matter is that the violent reaction of the nervous system to the situation criticism that caused the whitening, was above all able to cope with the serious urgency, emergency, danger or acute pain, putting in place an osmotic, chemical, metabolic and psychological battle that may have left hair on the ground dead and injured, safeguarding however, as much as possible, the death of much more useful cells, those of the main vital organs, such as heart, liver and brain, without which no hair in the world would survive, not only in color, but in its entire life cycle.
by Melania Rizzoli