A new study published in Nature Cell Biology has revealed that grey hair might be more than just a natural sign of ageing – it could be an indicator of the body’s internal battle against cancer.
Researchers from the University of Tokyo, led by Professor Emi Nishimura, investigated how melanocyte stem cells – responsible for pigment in hair and skin – respond to DNA damage. They discovered that when these cells experience a specific type of damage known as a “double-strand break” in their DNA, they self-destruct to prevent the risk of passing on dangerous mutations that could lead to cancer.
This self-sacrifice, while protective, reduces the number of pigment-producing cells over time, resulting in grey hair. The findings suggest that greying hair and the development of cancers such as melanoma may be two divergent outcomes of how stem cells respond to stress and damage.
Interestingly, the study found that not all types of cellular stress trigger this self-destruction. When exposed to ultraviolet light or carcinogens, the melanocyte stem cells often survive and continue dividing, potentially accumulating mutations that could lead to cancer. This dual response may explain why both grey hair and skin cancer become more common as people age.
The researchers hope that understanding this mechanism could lead to new strategies to eliminate high-risk cells before they become cancerous, potentially paving the way for innovative cancer-prevention treatments.
