A team of researchers, including Japanese scientists, has discovered the mechanism behind hair loss associated with aging, a finding that could pave the way for new ways to treat baldness.
In the study led by Tokyo Medical and Dental University's Emi Nishimura, the team determined that type XVII collagen, found near hair follicle stem cells beneath the scalp, is the key to thinning hair.
They identified this particular collagen as responsible for damaging the DNA of hair follicles. As the collagen disappears with age, the follicles shrink, causing hair loss.
The results of the study were published Friday in the journal Science.
The phenomenon was observed in the skin of mice that were 18 months old, the age at which hair loss in mice begins. The researchers found that older mice had fewer, thinner follicles than younger mice.
In mice lacking type XVII collagen, damaged stem cells turned themselves into skin cells and sloughed off from the scalp as scurf, resulting in hair loss.
Mice that continued to produce the collagen were found to be less prone to hair loss despite aging.
The team believes the same mechanism applies to humans.
In a separate analysis of the human scalp, the researchers discovered that hair follicles in women in their 50s or older had shrunk more than hair follicles in women in their 30s and 40s.
"I believe the results could help develop cures for baldness," said Nishimura, a specialist in stem cell biology.