Life's Great Mysteries - Why does my hair turn gray as I get older?

Maybe a better question is… why does my younger brother’s hair NOT turn gray as he gets older?

My first thought was that this is the universe’s way of letting everybody know that I am no longer a salubrious young man. After all, people need to know not to ask me to help them carry a couch up to their third-floor apartment.

Another thought I had was that my life is full of stress. I’ve heard stress causes hair to turn gray. Maybe I’m kind of like Barack Obama—his hair turned gray during his presidency. But actually, my life is pretty cushy and undemanding, so that can't be it.

As it turns out, human hair does not really turn gray due to stress. And in reality, hair doesn’t turn gray at all. Once a hair follicle produces hair, the color is set, and it never changes. Well, unless you color your hair, of course.

However, as we get older, our hair follicles produce less color. So, as our hair goes through its natural cycle of dying (dying, as in dead, not dyeing as in coloring) and being replaced with new hairs, the new hairs are more likely to grow in gray, at least after we turn 35 or so.

So, why doesn’t my brother have gray hair like mine? Because we are two different people, with different genetics. Yes, we share 50% of our genes, but that leaves plenty of room for variation, and his genetic makeup happens to delay his new hairs growing in gray until much later. Unfortunately for him, people will be asking him to help carry couches up flights of stairs for many years to come.

Photo Credits:
- Gray hair - DepositPhotos