A new study offers quantitative evidence linking psychological stress to greying hair in people.
The researchers analysed individual hairs from 14 volunteers. The results were compared with each volunteer’s stress diary, in which individuals were asked to review their calendars and rate each week’s level of stress.
The investigators immediately noticed that some grey hairs naturally regain their original colour, which had never been quantitatively documented.
The mitochondria connection between stress and hair colour differs from that discovered in a recent study of mice, which found that stress-induced greying was caused by an irreversible loss of stem cells in the hair follicle.