Khaberni - A recent scientific study conducted by researchers from the University of Tokyo indicated that graying might be a reflection of a natural defense mechanism within the body that protects it from skin cancer.
The study revealed that hair graying is linked to a biological process that could prevent melanocyte stem cells from turning into cancer cells. The researchers focused on the relationship between graying and melanoma, one of the most dangerous types of skin cancer, which affects more than 200,000 Americans annually.
Both conditions are associated with cells known as melanocyte stem cells (McSCs), which are responsible for pigment production in the skin and hair. When these cells are depleted or stop functioning within hair follicles, melanin production slows down, and hair turns grey or white.
In experiments, researchers exposed McSCs in mouse hair follicles to cancer-causing chemicals and observed that the damaged cells died, leading to color loss and hair turning grey, through the p53-p21 pathway—an established tumor-suppressing mechanism known as the "guardian of the genome" because it protects DNA from damage caused by external stresses.
Researchers believe that graying may be a sign of a natural process where the body disposes of damaged stem cells before they can become cancerous. However, the results showed that some cells might not follow this mechanism and instead turn into malignant cells.
Dr. David Sinclair, a Professor of Genetics at Harvard Medical School, who was not involved in the study, said that the research could pave the way for developing preventive measures against melanoma and other types of cancer. He explained to the 'Daily Mail' that the loss of pigment might be the body's way of preventing damaged cells from becoming cancerous, adding that understanding this process could open up new avenues for preventing melanoma before it appears.
There is no specific age for the onset of graying, though studies suggest the average is in the early forties, with some people showing the first white strands in their thirties. Exposure to cancer-causing toxins is not the only factor, as melanocyte stem cells naturally decline with age, gradually reducing melanin production.
Genetics and aging are considered the main causes of graying, yet psychological stress could also play a significant role, as the pigment-producing stem cells are affected by stress hormones like cortisol. When stress levels rise, these cells may cease to function, but if the stress is relieved before they are permanently damaged, they might regain activity and resume pigment production.
In 2021, a study from Columbia and Miami Universities found that some individuals managed to restore their natural hair color after reducing stress levels.
Results of the Japanese study
The University of Tokyo study, published in Nature Cell Biology, suggested that graying might indicate the strength of the body's defense system and its robust response to diseases. The lead author, Professor Emi Nishimura, stated in a press release:
"These findings redefine the relationship between graying and melanoma, not as separate conditions but as different outcomes of the stem cells' response to stress."
Warnings about hair dyes
Meanwhile, recent research has explained that many hair care products, including some dyes, contain formaldehyde, which is a chemical potentially causing cancer. Formaldehyde is used as a preservative but may turn into a gas over time through off-gassing, especially when heated.
Scientists warn that frequently inhaling these fumes could irritate the eyes and respiratory system, and increase the risk of head and neck cancers, particularly in poorly ventilated places like bathrooms or bedrooms.
Additional studies have shown that prolonged exposure to formaldehyde may contribute to the proliferation of melanoma cells in the lab, and cases of melanoma have been recorded in the nasal cavities of workers exposed to this substance for extended periods.
The Cleveland Clinic warns that melanoma is the most dangerous type of skin cancer, as it spreads quickly and can affect any organ in the body. Estimates indicate that about 212,200 cases will be diagnosed in the United States in 2025, potentially resulting in more than 8,000 deaths.
Doctors affirm that regular self-examination of the skin monthly to check for new or changing moles, along with periodic examinations by dermatologists, remains the most effective method to detect the disease early and reduce complications.
