What is the scientific cause of grey hairs?

Question

From a scientific and biological perspective.

Any don't just saw from old age or genetics. I know genetics have something to do with it, in your genes, but im sure there is more to it then that.

Answer 1

Each time your DNA is replicated, the very ends cannot be copied, and each time replication occurs, a little more is lost. Eventually, it will get passed the ends (telomeres, which are like protective caps, think of the plastic ends of shoelaces) and the gene that encodes for your hair color may be lost.

Answer 2

As we age, and for other reasons, the stem cells that provide the pigment for hair coloration die.  The way pigmentation works is if there is plenty of the pigment the color is dark and full.  No pigment yields white, dull hair.  

Researchers discover why we go gray

http://www.news.harvard.edu/gazette/dail...

Answer 3

Graying of hair is not an unusual thing to happen. The age when graying starts depends on one's genetic inheritance. Aging is often a reason that causes the hair to turn grayish. But premature graying of hair is a condition that demands the need to pay attention to the root cause. Nonetheless, graying of hair is a normal part of the aging process unless there is an underlying medical condition that is causing the lack of pigmentation.

Answer 4

The root of every strand of hair is surrounded by a tube of tissue under the skin that is called the hair follicle. Each hair follicle contains a certain number of pigment cells. These pigment cells continuously produce a chemical called melanin  that gives the growing shaft of hair its color of brown, blonde, red, and anything in between.

Melanin is the same stuff that makes our skin's color fair or darker. It also helps determine whether a person will burn or tan in the sun. The dark or light color of someone's hair depends on how much melanin each hair contains.

As we get older, the pigment cells in our hair follicles gradually die. When there are fewer pigment cells in a hair follicle, that strand of hair will no longer contain as much melanin and will become a more transparent color - like gray, silver, or white - as it grows. As people continue to get older, fewer pigment cells will be around to produce melanin. Eventually, the hair will look completely gray.