New research has found that the biological mechanism behind graying hair may be removing damaged cells that could otherwise become cancerous.
Graying your hair is a sign of aging that many fear, but it may have a hidden health benefit, according to new research from the University of Tokyo. , published in Nature Cell Biology, discovered a surprising biological link between hair aging and a defense against melanomaa dangerous form of skin cancer.
The research focused on melanocyte stem cells (McSCs), the specialized cells located in hair follicles that produce melanocytes. Using a murine model, scientists examined how these stem cells react to different types of non-DNA damagea process that naturally increases with age and exposure to factors such as UV radiation, pollution and chemicals, says .
The team discovered that when McSCs undergo DNA double-strand breaks, they undergo an irreversible process known as senescence-coupled differentiation, or senodifferentiation. In this state, cells stop dividing and mature prematurely, losing their stem cell properties. This change leads to graying of the hair.
However, when McSCs were exposed to certain carcinogens, the cells followed a different path. Instead of differentiating themselves, they resisted stress and continued to dividedespite DNA damage, a behavior that can contribute to the formation of tumors.
“In essence, the same population of stem cells can shut down and cause bleaching or continue to divide and risk becoming cancerous, depending on the nature of the stress they face,” explained study co-lead author Professor Emi Nishimura. Whitening and melanoma are like that.”divergent results from the answers from stem cells to stress”, rather than unrelated phenomena.
The findings suggest that the biological mechanism behind hair graying may have a protective function, removing damaged cells that could otherwise become malignant. However, the researchers warn that the results, based on animal studiesdo not mean that gray hair directly prevents cancer in humans.
