Gray hair is not wear and tear, it is a cleansing of our tumor cells.
For centuries, gray hair has been the universal symbol of aging, a simple aesthetic issue that reveals the passage of time or the excess of stress that sometimes occurs. it’s about covering with dyes. However, having gray hair can be good news for many people, since a study published in Nature Cell Biology just turned this idea on its head: white hair could actually be a biological defense mechanism. The fact that we begin to grow gray hair is for many people a great condemnation that reminds us that age forgives no one, and we even see young people with a lot of gray hair at an early age. But having gray hair can be a sign that is related to the risk of suffering from melanoma, which is one of the most aggressive skin cancers, especially when it is not caught in time. The dilemma of the cell. To understand why having a large amount of gray hair is good news, we have to go to the root of the hair. Here you will find the bulb of the hair folliclewhich is where the hair will grow. One of its fundamental components is the melanocyte stem cell, which is responsible for the pigment that gives color to the hair. That is why when these cells are affected is when you begin to have a color deficit. In this way, research indicates that when these cells suffer damage to their DNA, such as from exposure to the sun or according to agethe body activates a “checkpoint.” The mechanisms of action. When a cell with broken DNA appears on the scene, there is a chance that it will cause cancer if it begins to divide uncontrollably. In order to avoid this, stem cells use a process called “senodifferentiation” that causes the cell to stop dividing and be removed from the tissue. When these stem cells are eliminated, we are left without pigment reserves and the hair is born white, but the body has made sure to eliminate a potentially dangerous cell that could have generated a tumor if this defense system did not exist. The system may crash. Although our body has many defense systems to stop the proliferation of tumor cells, sometimes they fail and cancer is generated. Specifically, the study points to different carcinogens (including chemicals or UV radiation) that can ‘hack’ this cellular decision. Unlike pure radiation damage (which causes gray hair), carcinogens activate specific metabolic pathways (such as arachidonic acid metabolism) that force stem cells to survive and reproduce despite having damaged DNA. In this way, the stress of these carcinogens stimulates the stem cell niche to secrete a molecule called ligand KIT. This signal has the ability to block the “senodifferentiation” that we mentioned before, preventing damaged cells from being eliminated. The ‘good’ news is that the gray hair does not appear, but the bad news is that the damaged cells accumulate and expand, greatly increasing the risk of melanoma. There is, therefore, an antagonistic relationship: The fate of stem cells determines whether we will have gray hair or cancer. If the system works well, the cell is sacrificed and a gray hair emerges. If the system is circumvented by a carcinogen, the cell persists and the gray hair does not appear, but there is a greater risk of a tumor appearing. Aesthetic medicine. One of your goals right now may be avoid gray hair without the need for artificial dyes with the reactivation of these stem cells that have been ‘arrested’ and do not offer their pigment. But for these researchers we are facing a very bad idea. And they specifically point out that the repigmentation of gray hair in certain areas of the scalp could be, paradoxically, an early warning sign of melanoma, indicating that cells that should have ‘retired’ are returning to activity in an uncontrolled manner. In short, the next time you see a gray hair in front of the mirror, don’t just see it as a sign of old age. See it as a small victory for your body: a stem cell that decided to “retire” in time to protect you. Images | Alexandra Tran Natasha Brazil In Xataka | The rarest element on Earth aims to cure cancer. And Europe is already accelerating its production