The link between stress and premature gray hair is often mentioned ... This time it is scientifically established. According to a study published in the journal Nature on Wednesday, stress promotes the premature appearance of white hair.
The study, carried out by a team of researchers from the universities of São Paulo and Harvard, was carried out on mice. In these animals, stress damaged the stem cells at the base of the follicles, which produce the hair pigment.
"Everyone has an anecdote that tells how stress affects their bodies, especially their skin and hair, the only tissues that can be seen from the outside," says Professor Ya-Chieh Hsu, one of the authors of the study, which works at Harvard, at Science Daily. "We wanted to know if the link was real, and to understand how stress really affected these tissues," she says.
Permanent damage
In the study, the researchers explain in particular that the sympathetic nervous system, which manages, for example, breathing or the beating of the heart, has an important role in the appearance of white hair.
These nerves release noradrenaline, a neurotransmitter that "over-activates" pigment stem cells. These cells eventually disappear, permanently.
“After a few days (after exposing the mice to stress, editor's note), all the pigment regenerating stem cells were lost. Once they are gone, you cannot regenerate pigment at all. The damage is permanent, ”says Ya-Chieh Hsu.
Explore all the consequences of stress
The sympathetic nervous system is useful when it is activated in extreme cases of survival. It allows the animal to reach a high level of alertness. "But in this case, acute stress causes permanent damage to stem cells," she continues.
With these first discoveries, the group of researchers hopes to go further and explore all the effects of stress on body tissues and organs. "This is the first step towards a possible treatment that can stop or reverse the negative aspect of stress. We still have a lot to learn in this area, ”says Ya-Chieh Hsu.
