Why Stress Can Cause Gray Hair

  You may be familiar with these phenomena: some students gradually grow gray hair as the college entrance examination approaches; White hair.
  Most of us know that a lot of stress can lead to gray hair. But for this obvious question, it was not until recently that scientists found a preliminary answer from experimental black rats, and this answer also led to another big question.
  The reason why stress can lead to gray hair is due to the action of norepinephrine in our body. However, in order to get this simple answer, scientists have spent a lot of energy.
  It has long been thought that stressed immune cells “accidentally injure” pigment-producing cells, which leads to gray hair. But when scientists conducted experiments on black mice, they found that the hair of black mice lacking immune cells still turned white under extreme stress.
  In this way, immune cells are not the “culprit”. Scientists then turned to the hormone cortisol. Although the cortisol hormone is a hormone that we normally secrete in a stressful environment, it can help us mobilize the resources of the whole body in an instant, such as using other non-sugar substances to synthesize glucose, causing protein hydrolysis, and “forced” some resources for immune cell division in response to stress. But if the cortisol hormone is always at a high level in our body, it will consume our body’s resources, make us “exhausted” and weaken our immunity, and then a chain reaction will occur, causing all kinds of problems in our body . Scientists believe that these problems include: hair graying.
  But even when the scientists removed the adrenal glands of the black mice so that they could no longer secrete the hormone cortisol, the hair of the black mice turned gray under stress.
  Undeterred, scientists turned to norepinephrine — a hormone we normally secrete when we feel stressed. Scientists injected norepinephrine directly into black mice and showed that even in the absence of stress, the hair around the injection area turned white.
  How does norepinephrine turn hair gray? In the hair follicle, there are some stem cells stored, which act as “candidates” for pigment-producing cells. Whenever hair regenerates, some of these stem cells will be consumed to transform into pigment-producing cells, thus continuing to make the hair black normally. However, the number of these stem cells in the hair follicle is limited.
  Scientists have found that norepinephrine causes these stem cells to accelerate their transformation, and if the dose of norepinephrine is sufficient, it turns all the stem cells into pigment-producing cells, eventually overdrawing these stem cells, and no more pigment production Cells are born and white hair grows. And in some extreme cases, these stem cells will be permanently depleted, and “white hair” will never turn back to “black hair”.
  So how does norepinephrine get to the hair follicle? Scientists have long discovered that the sympathetic nervous system of animals secretes this hormone. This nervous system is very important. It is responsible for the “fight-flight” response of animals. Its nerve branches connect every hair follicle of the skin. Moreover, when animals When you feel stress, this nervous system is activated rapidly, secreting more norepinephrine, and these hormones come to the hair follicles at this time.
  The activation of the sympathetic nervous system is extremely beneficial to the survival of animals. When encountering danger, the extreme survival pressure makes it secrete more norepinephrine. This hormone in turn dilates the animal’s pupils and strengthens the beating of the heart, which then causes increased blood pumping and adrenaline secretion, etc., fully mobilizing the resources of the heart, liver, kidneys and other organs to cope with danger. Animals at this time often perform behaviors that break through daily limits, such as “jumping the dog in a hurry”.
  However, the scientists’ discovery also shows that animals’ success in coping with life-threatening risks may not be free. Since the nerve branches of the sympathetic nervous system spread all over the various organs of the animal body, in addition to overdrawing the hair follicle stem cells, there may be other costs that scientists have not discovered.
  Although human beings are no longer facing the pure life and death crisis like other animals, the situation of human beings is more complicated, and they face more pressure and challenges in various intricate social lives. Moreover, after some people have tasted the sweetness brought by the pressure, such as the extraordinary performance of students in important exams, the key decisions of entrepreneurs and the high-quality decisions of national leaders, etc., they will always put themselves under pressure intentionally or unintentionally in order to gain Play better. If this situation persists for a long time, the accumulated stress is no less than the survival crisis faced by other animals.
  So, relieving stress as much as possible will keep us healthy physically and mentally.