Hair grays because pigment-producing cells get stuck within the hair follicle, research suggests.
Gray hair is an inevitable part of growing older. The chances of hair graying increase 10% to 20% every decade after age 30, the Library of Congress notes. By age 61 to 65, 91% of people will display some level of hair graying, according to Melissa Harris, an associate professor of biology at the University of Alabama at Birmingham.
Read more: https://www.livescience.com/health/ageing/why-does-hair-turn-gray
