Complex Numbers

A Touch of Gray

Today's link is a few years old and from Popular Science, so one shouldn't take it as the final word on the subject. Still an interesting read.

    We finally know why stress turns your hair white  
Once those strands turn gray, they never go back.

I always figured it was more fright than stress. All the melanocytes just up and run away.

Not really, but I find it amusing.

In 1902, the British Medical Journal reported an unusual case of rapid hair whitening.

A 22-year-old woman “witnessed a tragedy of a woman’s throat being cut and the victim falling dead at her feet,” according to a physician at the London Temperance Hospital. The next day, the right side of her pubic hair turned white, while the left half remained black.

One wonders if that was the inspiration for Cruella de Vil.  

And it’s not just random violence that sends people’s pigment running—college exams, children, and work pressure appear to change our coloring, too.

Ah. No wonder I haven't gone gray yet.

But for millennia, scholars have been relying mostly on anecdotal proof and intuition to rationalize this phenomenon. In the absence of clear evidence, many scientists did not believe stress could turn hair snow white, instead arguing the change must be triggered by chemicals or strange immune system behavior.

Right, because stress couldn't possibly change body chemicals or the immune system.

A recent paper, published Wednesday in the journal Nature, may put some of these arguments to rest.

Again, it's not so "recent" anymore. And it's one paper. It's not definitive. That doesn't mean it's wrong.

In the study, stem cell and regenerative biologists from the United States and Brazil reported that stress can indeed cause hair to lose its pigment—and they identified a cellular pathway by which it can occur.

That last bit is, in my view, the important part.

To study this vexing relationship, the researchers created an elaborate animal model, which basically involved trying to turn black-haired rats white with lab-made stressors.

I get why they need to do animal testing for this sort of thing, and stressing out rats isn't going to raise a lot of public ire. Still... poor rats.

Perhaps unsurprisingly, nociception-induced stress, which the scientists stimulated by injecting the rats with resiniferatoxin, an analogue of the chili pepper compound capsaicin, worked best and fastest.

As a sample of one, I can definitively say that overdosing on capsaicin doesn't necessarily turn one's hair white.

Having identified the optimal way to make a rat panic...

Ah, there it is: the phrase at which point I hit "save bookmark."

...the team began searching for corresponding changes in the physiological pathways that give rise to coat color.

There follows more description of the experiment.

Hair still holds many secrets. We don’t know why hair loss plays out differently on someone’s scalp than on their face or, for that matter, their back.

See, I don't mind getting gray hair. Baldness concerns me way more, though I have to admit it would make a few things easier.

In recent years, there’s been a surge in research and development for anti-balding solutions—and many of them show promise. Terskikh, for his part, is working on regenerating hair from scratch using things like pluripotent stem cells. If it works, we’ll have an unlimited supply of hair—presumably in every shade.

Great, just what we need: anime hair, no hair dye necessary.

Won't happen, though. The Manic Panic industry lobby is just too powerful.