While it has long been known anecdotally that stress can turn hair white, no one knew precisely why—until now.
In a chance discovery, researchers from the University of Sao Paul in Brazil and Harvard University in the U.S. found that melanocyte stem cells in mice that control skin and hair color became damaged after intense stress. During an experiment, mice were inflicted with pain which in turn triggered the release of cortisol and adrenaline. These hormones caused acute stress, affecting the mice nervous systems, causing their hearts to beat faster and their blood pressures to rise. The result: After a few weeks the dark-furred mice turned completely white.
“I expected stress was bad for the body,” said Professor Ya-Cieh Hsu, research author from Harvard University, to BBC News. She added: “But the detrimental impact of stress that we discovered was beyond what I imagined. After just a few days, all of the pigment-regenerating stem cells were lost. Once they’re gone, you can’t regenerate pigment any more – the damage is permanent.”
The study, published in Nature, revealed that researchers could block the mice fur from graying by treating the mice with an anti-hypertensive that controls high blood pressure. Additionally, they found that they could prevent the change in fur color by suppressing the protein cyclin-dependent kinase (CDK).
While not a cure for gray hair, in the future the findings could help delay the onset of graying hair by targeting CDK with a drug.
“Our discovery, made in mice, is only the beginning of a long journey to finding an intervention for people,” said Professor Hsu to BBC News. “It also gives us an idea of how stress might affect many other parts of the body.”