Scientists have discovered the reason why human hair loses its color and turns gray with age New York Post. According to the team of scientists, the melanocyte stem cells become trapped inside the hair follicle and cannot produce pigment.
The findings were published Wednesday in the peer-reviewed journal Science Nature. For the study, the scientists tracked individual cells in the fur of mice for two years to determine how the hair turns gray, closely examining melanocyte stem cells known to control hair color. They used special scans and laboratory techniques to study the cell-aging process.
They discovered that the pigment-producing part of the stem cell changes as the mice mature. “The melanocyte stem cell system fails earlier than other adult stem cell populations, leading to hair graying in most humans and mice,” the study says.
As hair ages, falls out and regrows, melanocyte stem cells become trapped in an area of the hair follicle known as the hair follicle bulge. As the stem cells stop circulating around the follicle and become stationary, they do not mature into full-fledged melanocytes. The hair then turns grey, white or silver as the pigment is not produced.
“This is a big step forward in understanding why we are gray,” said Mayumi Ito, an author of the study and a professor of dermatology at New York University’s Grossman School of Medicine.
He explained, “Loss of chameleon-like activity in melanocyte stem cells may be responsible for graying and loss of hair color.
The researchers also suggested that if their findings hold true in humans, they could open up a potential way to reverse or prevent gray hair.
The study’s principal investigator, Gui Sun, said, ”The newly discovered mechanisms may have the same stable position of melanocyte stem cells in humans. If so, this provides a potential pathway to prevent or stop graying of human hair by helping the congested cells move back between growing follicles.