STRESS really does turn you grey as it uses up stem cells that give hair its colour, a study shows.
Being under pressure at home or work triggers the sympathetic nervous system — part of the body’s fight or flight mechanism.
The nerves release the chemical norepinephrine which is taken up by pigment-regenerating stem cells at the bottom of each hair, biologists found.
The stem cells go into overdrive and get used up, tests on mice showed.
Researcher Professor Ya-Chieh Hsu said: “When we started to study this, I expected that stress was bad for the body — 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.”
It was said Queen Marie Antoinette’s hair turned white the night before she was beheaded in the French Revolution.
Former US presidential candidate John McCain, went white from severe injuries as a prisoner during the Vietnam War.
And Prime Ministers Tony Blair and David Cameron went grey early with the strain of the job.
The latest findings come from researchers at Harvard University.
They had thought hair went grey because of an immune system response or a reaction to stress hormone cortisol.
But mice lacking immune cells or the gland which produces cortisol still turned grey.
Instead, the researchers realised the sympathetic nervous system was probably to blame.
Lead study author Dr Bing Zhang said: “Acute stress, particularly the fight-or-flight response, has been traditionally viewed to be beneficial for an animal’s survival.
“But in this case, acute stress causes permanent depletion of stem cells.”