There’s no surer sign that you’re getting
old than finding new gray hairs. But scientists have finally identified a gene involved in
the hair-graying process. What does this mean and how does your hair actually go from colored
to gray? Watch and weep. Geneticists recently examined the DNA of more
than 6,000 people and found specific genes that influence things like baldness, beard
thickness, hair curliness, and even unibrow…ness. But the find that got the most attention was
a particular variation in the IRF4 gene that affects when your hair goes gray. Finding
this specific graying variation in the gene could help scientists develop products to
slow the graying process. Or, speed it up, I suppose, if you want to be a silver fox or
avant garde hipster. But we all actually start out gray, in a way.
Before your hair pops out of your scalp, it’s completely white. It gets its color from chemistry—specifically
a group of pigment molecules called melanin, which also determine your skintone and eye
color. For hair, there’s eumelanin that creates dark shades and pheomelanin that produces
lighter hair colors. The proportion of these two types determines your—and everyone else’s—hair
color. How that color gets into your initially colorless
hair is up to your follicles. Every hair follicle in your scalp contains cells called melanocytes,
which produce melanin. As hair grows in the follicle, melanocytes inject melanin pigments
into your hair cells that contain keratin, a protein that’s also in your skin and fingernails.
So as your hair grows out of your head, it gets dyed with its natural hue. Over time,
our melanocytes produce less pigment, so our hair starts to lighten as we age. Scientists have recently found that as we
get older, our hair follicles start accumulating hydrogen peroxide—the same stuff people
use to bleach their hair. Some hydrogen peroxide is normal. We actually make our own H2O2 as
melanocytes color our hair. Enzymes, especially catalase, break down hydrogen peroxide and
keep its concentration in check. But things get out of whack when older follicles can’t
generate enough catalase. Higher concentrations of hydrogen peroxide attack tyrosinase , an
important enzyme in melanin production. No melanin, no color in your hair. If you haven’t gone gray yet you probably
will around the same age as your parents did. But what about factors outside of age and
genetics? A recent study suggests that smoking can result in early onset graying. And people
are always saying stress brings on the gray, right? Just look at how gray presidents get
while they’re in office. Some researchers say emotional stress could accelerate what’s
called oxidative stress, the damage caused by reactive oxygen species like hydrogen peroxide.
But others contend there isn’t solid scientific evidence backing this up yet. I guess you
could call all of these hypotheses a gray area. At any rate, it’s probably not worth stressing
about going gray, anyway. It’s completely natural and you can totally rock the look.
Share a pic of your favorite gray-haired celebrity or your own cool silver ‘do in the comments.
The Speaking of Chemistry gang needs ideas. Special thanks to Jerry Weissmann, an emeritus
professor at the New York University School of Medicine for his help with this video.
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