Many people joke about stress causing gray hair. But new evidence suggests this old “myth” is actually true. The body’s stress response, known as fight-or-flight, plays a part in making hair turn gray sooner.

Why hair has color

Your hair contains special stem cells called melanocytes. Melanocytes live in the hair follicle at the hair root. They make pigment, or color, that gives your hair its natural hue.

The natural aging process causes melanocytes to disappear, leading to gray hair. Once gone, melanocytes don’t come back.

Stress and going gray

Researchers say that certain kinds of stress may cause hair to turn gray. It happens because certain nerves that work with the fight-or-flight response affect the body — including hair follicles.

These fight-or-flight nerves release a chemical called norepinephrine directly into the follicle. Then, the norepinephrine forces the melanocyte stem cells to leave.

Without these stem cells, the hair follicle can’t produce new color. So, the hair turns gray or white.

Manage stress

Stress can be hard on your health — not just your hair. If you have high stress often, talk with your doctor about it.

Source: National Institutes of Health