why and how do people grow gray hairs?

Question

Just a random thought, does it have any uses, how does it happen and why?

In: Biology

Answer 1

Remember that hair is coloured by melanin. Brown hair is eumelanin and red hair pheomelanin. Same stuff thats in your skin and eyes. When you age your hair stops being able to produce this protective melanin. So grey hair is also more likely damaged by UV rays from the sun.