Why does hair turn white? The pigment cells in the hair follicles die.
Our hair is colored by melanin that is produced by the pigment cells in each hair follicle. Melanin is what colors our skin as well. Melanin is produced in cells called melanocytes and different quantities or types of melanin can alter the color of your hair, skin, or eyes. When you are out in the sun and you go brown, it is your body releasing more melanin to protect you from the UV rays.
There are three main types of melanin, and each one is a slightly different color. They are all found in the body but not all in the skin or the hair. Eumelanin is a dark brown color. If your hair is dark brown, then it has lots of eumelanin in it. Pheomelanin is yellow-red. If your hair is red, then you have a lot of pheomelanin in it. Neuromelanin is very dark brown. It is only found in the brain, and it works to protect neurotransmitters, although people are not sure why. Research is being done with it because it could be a treatment for Parkinson’s disease.
Hair is made of keratin, which is a type of protein. It is the same material that our nails are made of and grows in a similar way. The part of the hair that we can see is only the bit that pokes out through our skin. The rest of the hair is hidden deep in the epidermis layer of the skin. The hair poking out through the skin is made of dead cells, but the lower part of the hair is still alive. The very root of the hair rests in something called the hair bulb. This has a blood supply and nerve endings. That is why it hurts to pull your hair out. The hair cells begin to grow in the hair bulb and as they multiply, they push the cells above them further up, which is how the hair grows. There is also a muscle connected to the hair bulb, which can make the hair stand up when it is contracted. This is what makes our hairs stand up when we are cold and why we get goosebumps.
The pigment that colors our hair comes from the melanin which is made by the melanocytes. The melanocytes are located in a bulge that is above the hair bulb, but below where the hair reaches the upper layer of skin. The melanocytes produce melanin and it travels down to the bottom of the hair bulb where it is combined with the new keratin cells that are growing and becoming hair. Different types and different quantities of melanin make the hair different colors. Different quantities of eumelanin can make hair from black to blond, and different quantities of pheomelanin mixed with eumelanin can make different shades of red. The color of our hair is determined by our genes and there is nothing we can do about that. However, hair color might change with the seasons because sunlight can bleach the melatonin.
So, why does our hair go white when we get older? Basically, because the melanocytes that make the melatonin die. Hair is naturally white, as are your nails, which are also made of keratin, and it is the melanin which gives hair its color. All of the cells in our bodies die and new ones are born. However, over time, some cells die, and no new ones are created. This happens with the melanocytes in the hair follicles. As they slowly die, they produce less melanin, which means the color of the hair gets ever so slightly lighter because more of the white is showing through. The more melanocytes die, the closer the hair becomes to grey. There is still some color, but not a lot. When the melanocytes have completely died and there is no melanin coloring the hair, it is completely white, which is its color without coloring.
Different people go white at different times and different races of people also go white at different times. It is a natural part of the aging process, but it doesn’t only happen because of aging. A lack of vitamin B12 can stop the melanocytes from producing melanin, as can some diseases. Stress doesn’t necessarily make people go grey, but smoking can. Smokers are 2 and a half times more likely to have white hair before they are 30 than nonsmokers. The smoke from the cigarettes can also make the white hair go yellow.
Some people think that pulling out a grey hair will either fix the problem or will make the problem worse, but it will do neither. The problem lies with the lack of melanin in the root of the hair and if the hair is plucked out another grey one will simply grow in its place. And this is what I learned today.
Photo by cottonbro studio: https://www.pexels.com/photo/elderly-couple-smiling-together-7236499/
Sources
https://en.wikipedia.org/wiki/Neuromelanin
https://karger.com/spp/article/35/2/65/826910/Influence-of-Ethnicities-and-Skin-Color-Variations
https://en.wikipedia.org/wiki/Melanin
https://medlineplus.gov/genetics/understanding/traits/haircolor/
https://kidshealth.org/en/kids/gray-hair.html
https://www.webmd.com/beauty/ss/slideshow-beauty-gray-hair-facts
https://www.u-tokyo.ac.jp/focus/en/features/z1304_00245.html