Have you ever seen anyone�s hair suddenly go grey or white? It can happen to survivors of serious illness or a life-altering shock. I used to think that only happened in movies. A new study makes the connection to our sympathetic nervous system which is also our fight or flight response. It�s a release of hormones that increases our alertness and heart rate so we�re ready to act. What does this have to do with hair?
Well, we�ve known that stress damages stem cells at the base of each hair follicle. Normally these stem cells mature into melanocytes that produce pigment in skin and hair. Stress makes them mature faster, decreasing their numbers which causes grey or white hair. Researchers had thought that our immune system attacked these melanocytes or that the stress hormone, cortisol was responsible. But the new study showed it�s the sympathetic nerve cells associated with hair follicles that causes greying.
These nerve cells release a neurotransmitter, noradrenaline into the melanocyte stem cells increasing their rate of maturation. In lab cultures, human melanocytes treated with the neurotransmitter grew rapidly. And scientists had already shown with other experiments that depleting melanocytes does lead to grey hair.
So, if we blocked the release of noradrenaline, would you be able to stop hair from going grey? Yes, in lab mice, that worked but it also blocked the fight or flight response. Even though that�s not an option, this is a promising start to less grey hair.
For more information…
How the stress of fight or flight turns hair white
Signalling from the sympathetic nervous system of mice when subjected to stress leads to the depletion of a stem-cell population in their hair follicles. This discovery sheds light on why stress turns hair prematurely grey.
Can Hyperactive Fight-or-Flight Responses Cause Gray Hair?
Hyperactivation of the sympathetic nervous system may cause hair whitening...
How stress causes gray hair
Stress can cause hair to gray prematurely by affecting the stem cells that are responsible for regenerating hair pigment. The findings give insights for future research into how stress affects stem cells and tissue regeneration...