Scientists have discovered the reason why human hair loses its colour and turns grey as we age, reported New York Post. According to a team of scientists, melanocyte stem cells become stuck inside the hair follicle and are unable to produce pigment.
The findings were published Wednesday in the peer-reviewed, scientific journal Nature. For the study, scientists spent two years tracking individual cells in the fur of mice in order to determine how hair turns grey and closely examined the melanocyte stem cells known to control hair colour. They used special scans and lab techniques to study the cell-ageing process.
They discovered that the pigment-producing part of a stem cell would change as the mice would mature. ''The melanocyte stem cell system fails earlier than other adult stem cell populations, which leads to hair greying in most humans and mice,'' the study says.
As hair ages, sheds and grows back, melanocyte stem cells get stuck in a part of the hair follicle called the hair follicle bulge. As the stem cells stop roaming around the follicle and become fixed, they fail to mature into fully-fledged melanocytes. The hair then turns grey, white or silver because no pigment is being produced.
Mayumi Ito, the author of the study and dermatology professor at New York University's Grossman School of Medicine, said, “This is a really big step forward in understanding why we grey.”
He explained, ''It is the loss of chameleon-like function in melanocyte stem cells that may be responsible for greying and loss of hair colour.''
The researchers also suggested that if their findings hold true for humans, they could open up a potential way to reverse or prevent grey hair.
The study's lead investigator, Qi Sun, said, ''The newfound mechanisms raise the possibility that the same fixed-positioning of melanocyte stem cells may exist in humans. If so, it presents a potential pathway for reversing or preventing the greying of human hair by helping jammed cells to move again between developing hair follicle compartments.”
