Study reveals why hair grays—and hints at potential reversal treatment

At New York University, scientists have traced the quiet disappearance of hair color to a failure of movement — stem cells that once traveled freely through the hair follicle become stranded with age, cut off from the signals that would renew their purpose. Published in Nature, the research offers not merely an explanation for graying but a map of a cellular journey interrupted, one that may eventually guide medicine toward restoration rather than concealment. The discovery, made in mice, reminds us that aging is often less a destruction than a gradual loss of flexibility — and that understand