50 Shades of Grey: Why hair turns grey as we grow older
US scientists have found a new reason for why hair turns grey as we age, beyond stress, diet, and genetics.
A new study says it is likely because stem cells – which give hair its natural pigment – get stuck as hair ages.
Hair follicles in the skin contain melanocyte stem cells (McSCs), which produce protein pigments that give hair its colour.
Stem cells can transform into various cell types and travel between different hair follicle growth areas. Hair turns grey when these cells stop migrating.
Researchers studied this process in mice by focusing on McSCs, which are also present in humans.
During normal hair growth, McSCs regularly oscillate between compartments of the developing hair follicle.
With age, as hair sheds and regenerates, an increasing number of melanocyte stem cells become trapped in the hair follicle bulge and remain there.
When these cells become fixed in the stem cell compartment, they fail to mature into melanocytes and stop producing pigments, resulting in grey or silver hair.
Scientists believe that if these findings are also true for humans, then they could pave a potential path to reverse or prevent grey hair.
According to the British Association of Dermatologists (BAD), this study can also help in understanding the treatment of some kinds of cancers better.
The findings of the study could also help in the treatment of alopecia areata, an autoimmune disorder in which regrown hair in individuals appears white.