Why does our hair turn gray?

Today’s Video of the Day comes from the American Chemical Society’s Reactions series and explains the science behind why our hair turns gray as we age.

Scientists have only recently identified the specific variation in the IRF4 gene that determines when your hair begins to turn gray. It turns out that before your hair grows out of your scalp, it’s actually white. The color comes from a group of pigment molecules called melanin. Pheomelanin creates lighter shades, while eumelanin produces a darker color, and the proportion of each determines each person’s hair color.

As you grow older, less pigment is produced, so the hair begins to lighten. At the same time, your hair follicles begin accumulating hydrogen peroxide, which begins blocking the the production of melanin.

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By Rory Arnold, Earth.com Staff Writer

Source: American Chemical Society