Why does our hair turn gray as we grow older?
Everybody gets older day by day and with old age comes a lot of interesting changes. They say that with age comes wisdom. But what they forgot to tell you is that also with old age comes a lot of gray hair.
But where does gray hair come from? I’m pretty sure you have seen a lot of grown-ups with gray hair. But if you ask them they will tell you that it wasn’t always gray. Everyone who has gray or white hair used to have hair that was a different colour while they were younger like blonde or brown or red.
There are many internal as well as external factors that can change the colour of your hair as you grow older such as genetics, hormone, age, climate, toxins and even chemical exposure. The most common natural factor apart from old age is genetics. Check with your parents or grandparents and find out when they went gray. That’s how you’ll know when your hair is likely to turn gray as well.
Hair turns gray as people turn older because the stuff that gives hair its colour starts to run out. Each of the hair strands that we have on our head grows under its own single spot under the skin called a follicle. A follicle is like a tiny hair making factory putting together fibers to make a strand of hair and then adding colour to it. That colour comes from something called as melanin.
Some interestingly unknow facts about melanin
Melanin formation happens before we are born. We have melanin in other parts of our body too. It gives colour to our skin and even to our eyes. That is why we all look so different from each other.
Also, did you know that all hair is white before it grows. If you pluck out a strand of hair from your head, you will see a tiny bulb of white at the bottom of the strand.
So how does your hair go from colour to gray?
To answer that we need to first know how hair gets its colour in the first place.
There are two types of melanin. The dark pigment is called eumelanin and it makes the hair colour black or brown. The light pigment is called pheomelanin and it makes the hair red or blonde. Both, eumelanin and pheomelanin blend together to create a broad spectrum of beautiful hair colours. These pigments are composed of stem cells called melanocytes that are positioned on the skin’s surface through which the hair follicles grow. Melanocytes are little tiny things inside the hair follicles that are making even more melanin every day! Since each hair follicle grows separately and contains its own amount of melanin, some hair will turn gray while others will not. Every day the follicles add more fiber to each strand of hair that helps it to grow longer. At the same time these melanocytes inject melanin into cells that contain keratin. Keratin is what makes up the protein in the hair. Keratin is naturally colourless and obtains its colour from the melanocytes. The colour of the hair that you are born with is largely dependent upon genetics. Also, each hair does not grow forever. After a certain time, each hair falls out and the follicle starts over with a new strand of hair. Every time the hair falls out, the follicle also loses a little of the melanocytes that was making the melanin. But it keeps coming back with each new hair strand. However, after a lot of years of growing new hair, the follicles start to run out of melanocytes. The hair follicles can keep producing new hair strands but without enough melanocytes to produce the melanin they cannot add colour to it anymore. And without the colour from the melanin, the hair turns gray or white. As you grow older, the functioning capability of your melanin cells start to decrease gradually. They become less active and may even die. The less melanin you have, the greyer your hair becomes. So as a result, less colour is conferred to the keratin and your hair eventually turns lighter to the point where it becomes gray.
At first, only a few hair follicles run out of melanin. So, the person only has a few strands of white or grey hair. As more and more follicles run out of colour over time, you’ll see more gray hair until eventually it all turns gray.
Everybody’s hair starts to turn gray at different times because we are all so different. Some people have their first gray hair even before they turn 20 while most others start to gray during their 40’s. Growing gray hair is just a normal part of getting older. Some people choose to dye their hair while others like to leave it natural.