Scientists found that stress turns hair grey in mice. Stem cell biologists from Harvard tested mice to find how stress affected them. The scientists injected the mice with the heat-giving ingredient in chili peppers. This caused a hair-colouring chemical in the mice to overwork in reaction to the stress. It used up all colour-regenerating cells. The mice's hair quickly turned white. A researcher said this was, "beyond what I imagined".
People have always believed that stress turns hair grey. France's Queen Marie Antoinette's hair supposedly turned white before she was beheaded. More recently, the hair of presidents have quickly lost colour. The strains of leadership have gone to the roots and follicles. The researcher said the loss of the colour-regenerating cells cannot be reversed. She said: "The damage is permanent." She thinks stress could also accelerate the aging process.