Why Does Hair Turn Gray?

Skin Care
Our hair all goes gray at different times. If you’re worried about when you’ll go gray, then look to your parents for an idea of when you’ll be sporting silver strands.

Everyone goes gray eventually, but why does it happen?

In our culture, we widely consider graying to be a sign of aging. Note, though, that scientists have actually found no link between physical aging in the rest of the body and graying hair (New York Times).

As it turns out, researchers have only recently uncovered some of what causes people to go gray. This could be a step toward understanding the aging process and what happens in the body

Why Does Hair Turn Gray?

Hydrogen peroxide
Hydrogen peroxide, the same stuff that can make you “bleach blond” when applied topically, can make you grey from the inside out.  (Photo credit: Wikipedia)

Before explaining why you gray, allow me to explain how hair color works. Melanin — created by melanocytes — is what gives you hair color. There are different kinds of melanin for different hair colors: eumalinin for black or brown hair and pheomelanin for red or blond hair (Popular Science). Hair turns gray because the melanocytes stop producing melanin. This happens one by one because there isn’t one central location for melanin — which explains the gradual shift to silver.

So why do these melanocytes stop producing melanin, or, rather, sending it out? Hydrogen peroxide, the same chemical that when put on hair can make it a vibrant bleach blond.

When researchers were studying vitiligo, a condition that causes patches of skin to have no color (or melanin!), they started thinking that perhaps the cause of this condition — a buildup of hydrogen peroxide — could be the cause (New York Times).

Hair cells produce minute amounts of hydrogen peroxide and as we age, we have less catalase, the enzyme that breaks it down. As the hydrogen peroxide builds up over time it blocks the melanin, causing hair to be bleached and lose pigment — or go gray! (Science Daily).

A Few Reasons for Your Grays

Your mom and dad are the main factor in why you go gray.

Your Genetics Give You Grays

Unsurprisingly, your mom and dad’s trajectory into silver fox-hood (because I think men and women can be silver foxes), should give you a pretty solid idea of when your own hair will start to turn (Medline Plus).

Genetics play a pretty sizable role in determining when you’ll go gray. It seems we all have a genetically pre-programmed time to gray. Essentially, your genetics determine the production capabilities of melanocytes, which give your hair its color (Popular Science).

Your Gender and Ethnicity Give You Grays

Men will generally start to gray before women. Those first silver strands generally show up around age 30 for men and age 35 for women. But some people don’t see grays until their 40s, or even their 50s.

And race plays a role as well. In general, white people tend to go gray sooner than Asian people, who, in turn, tend to go gray sooner than black people. (Medline Plus).

The Environment Gives You Grays

Pollution, free radical damage, toxins, etc. all contribute to giving you grays (Medline Plus). But as one researcher pointed out, it’s odd that some hairs are more affected than others, suggesting that we have more to uncover (New York Times).

Does Stress Cause Grays?

There’s some evidence pointing to a correlation between stress and grays, but not enough research has been done to show why.

It’s part oldwife’s tale, part contemporary urban legend, that people who stress out go gray faster. But those stories are true sometimes, right? The Daily Mail UK published an article about women starting to go gray younger and younger. But is there scientific proof to back this up?

Well, it would appear that there might be something to the idea that stress causes graying.  “Might” being the operative word. Scientists are looking into how stress affects grays and are giving weight to the idea that it might have an affect (Scientific American). But even if stress did play some role, it’s still genetics that really paint those strands silver (New York Times).

Bottom Line

Gray hair happens to everyone. It’s the melanocytes in the hair follicles being stopped-up by naturally produced hydrogen peroxide. It’s primarily caused by genetics, but extrinsic factors in the environment and stress can also play some role as well.

While we often view it as a sign of age, it’s natural and, if you ask me, can look very becoming on men and women alike.  So, if you’ve got some grays going on, I say: Go get ’em, you silver fox!


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  • Stacey

    Greys at 29! Youngest in the family. None of my 4 siblings are grey (34-45 years old!) my dad started greying in his late 40’s and until me that was the earliest grey head in the family! On both sides! I look like my dad so I’m not from a brief affair with a milkman! I am however, the most stressed out on. All of the time. I hate being the exception to the rule! Booooo! 🙂

  • Great post! I am always interested in others views on why hair turns gray. Thanks.

  • Natalie Bell

    @Lynn — I know a ton of people who have gotten grays in their 20s. The enzyme is called catalase.

    @Eileen — I think people are really starting to realize how lovely salt ‘n’ pepper hair can be! I’m glad that you’re wearing it proudly. 🙂

    @L — Some people just go gray sooner than others, even if they aren’t exposed to stress or toxins. Salon bills for grays can definitely be rough. I’m sure that when you’re ready to let them go you’ll look lovely!


  • L

    Interesting. Like the other commenter, I’ve started getting a significant sprinkling of gray (actually bright white for me) in my early 20s. I actually got my first 10 or so in my late teens.

    I haven’t experienced unusual stress or exposure to toxins, but my grandmother’s hair turned bright white pretty early. I’m not too alarmed, but the high salon bill due to dying my hair to cover the change kinda stinks. I may let them go at some point, but not at 23. (My hair is probably only 1% white, but that’s still a bunch of strands that are very bright against my thick, very dark hair)

  • Eileen

    Interesting article. My uncle was a silver fox in his twenties so I had a good role model when my natural black hair began to gray. Although the gray started coming in while I was very young, at 68 my hair is only about a third gray. I get compliments galore from men and women, young and old, on my long salt ‘n pepper hair. I keep it well conditioned and wouldn’t dream of coloring it.

  • Lynn

    I’ve been getting a bunch of grey hair and I’m on in my mid 20s! my parent’s didn’t get it til this 40s.
    Do you know what’s the enzyme that is needed to break down the hydrogen peroxide in the hair?

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