Why is it that as we age, our hair starts turning white? What causes this?
-MC
Since this is not my area of expertise, I searched Google under the key words "hair turn white" to get this source:
http://kidshealth.org/kid/grownup/getting_older/gray_hair.html
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps. Thanks for asking.
It did...thanks!
-MC
As we age, the color of our hair can change, typically turning white or gray. This happens because of a natural process called graying or greying of hair, which occurs when melanocytes, the cells responsible for producing pigment in our hair follicles, start to decrease in number or become less efficient in producing pigment.
To understand this process better, we need to delve into the anatomy of hair. Each hair follicle contains pigment-producing cells called melanocytes, which produce a pigment called melanin. Melanin comes in two types: eumelanin, which gives hair darker colors like brown or black, and pheomelanin, which gives hair lighter colors like red or yellow.
The melanocytes transfer melanin to the keratinocytes, the cells that make up the hair shaft. When the hair strand grows, it emerges from the scalp with the color determined by the amount and type of melanin present.
However, as we age, the melanocytes in our hair follicles gradually start to decline. This reduction in melanocyte activity leads to a decrease in the production and distribution of melanin to the hair strands. Eventually, some hair follicles may stop producing melanin entirely, resulting in hair that appears white or gray.
The exact cause of this decrease in melanocyte activity is not fully understood, but it is believed to be a combination of genetic and environmental factors. Factors such as genetics, stress, hormonal changes, and the accumulation of oxidative stress over time are considered to contribute to the graying process.
So, to summarize, the graying of hair with age occurs due to a decline in the number and activity of melanocytes, which leads to a decrease in melanin production and distribution to the hair strands.