Grey hair could actually be a sign that you have a bit of added protection against cancer, suggests a Japanese study.
Hair greys when colour-producing stem cells, called melanocytes, die off in hair follicles. DNA damage - which can lead to cancer - increases in melanocytes as people age. But gray hair means that melanocytes are no longer present and thus cannot pass on cancer-causing mutations, the Toronto Star reported.
The finding, published in New Scientist magazine, might help in the development of new cancer treatments, said Dr David Fisher, director of the melanoma programme at Massachusetts General Hospital and Harvard Medical School.
"The study demonstrated that stem cells containing DNA damage are removed, and it is theoretically possible that such a mechanism may exist for numerous types of cells (outside of hair follicles) in the body," Fisher wrote.
"The 'protection' concept from gray hair relates to the fact that damaged melanocyte stem cells have been removed (thus, the gray)," he said. "Perhaps if we had a similar mechanism of removing cells from the epidermis, melanoma may be less common." – (HealthDay News, June 2009)