According to a new study, the premature appearance of grey hair, or rather its appearance with growing age, is a manifestation of stress. The research has found that stress activates nerves in the head that are part of fight or flight response, which causes permanent damage to hair follicles because the pigment regeneration stem cells have been damaged beyond repair.

After eliminating the non-obvious reasons for greying of hair, researched zeroed in on sympathetic nerve system responsible for the body’s fight or flight response. Sympathetic nerves branch out to each hair follicle in the skin of the head.

Stress causes these nerves to release the chemical called norepinephrine, which is absorbed by nearby pigment regenerating stem cells causing the stem cells to activate excessively, and there by prematurely greying your hair.