Chances are good that you know someone with gray hair. For most people, it’s just a thing that happens with aging. At some point, you’ll know you’re ‘old’ when your hair begins to turn gray. When this happens tends to vary on a case by case basis, and in fact, some people get gray hair very early in life, as early as their twenties in some cases, while others retain their natural hair color for a very long time, even well past middle age. Generally, genetics play a significant role in when our hair grays, but there are other factors.
What Determines Hair Color?
It’s important to understand what gray hair represents in the first place to completely understand the process of graying. The obvious answer is ‘you’re getting old,’ but the truth is a little more complicated than that. Hair and hair color, are factors that like almost every other detail about a person are determined by their genes. The blueprint used to design their body, provided by their parents, determines texture, amount, and color of hair. This is the result of two types of melanin; eumelanin causes dark hair, while pheomelanin creates lighter hair. Think black and brown vs. orange and yellow.
These two types of melanin are produced by cells known as melanocytes. The melanocytes are located at the base of each hair follicle, so that as the hair grows out from the follicles, it is continuously fed pigments by these melanocytes. It is through the specific ratios of eumelanin and pheomelanin that the hair receives from the melanocytes that determine the resulting color of the hair as some shade of blonde, brown, red, or black. These differing ratios determine why two people may have the same hair color, and yet different shades of that color, even within the same family.
So What About Gray Hair?
So, if hair color is naturally determined by the melanin produced by melanocytes, where does gray hair come into the picture? As we age, the wear and tear of life takes its toll on our bodies, just like everything else. In the case of the body, cells that grow old or suffer damage began to replicate incorrectly. Those blueprints are being misread now, and that leads to a whole host of changes. When it comes to our hair, hair follicles can lose their melanocytes as a result of cellular damage, which means the hair will not receive melanin for pigmentation.
When hair does not receive pigmentation from the melanocytes, it comes out of the head gray or white, instead of the ‘natural’ color. What this means is that the graying of hair is a strand by strand, follicle by follicle process. Hair does not turn gray all at once, and as long as some of the hair follicles have melanin-producing melanocytes, those particular hairs will continue to produce colored hair during each hair growth cycle. In fact, it is only when a significant number of melanocytes have suffered cellular damage that the hair overall will turn gray or white.