Compare a picture of a fresh-faced Barack Obama in 2008 to a picture of the president from today, and you'll probably notice a difference. It's not just that in today's pictures, the leader of the free world might be using a selfie stick. He's also going to look older, grayer. Well, obviously, seven years have passed. But just 44 days into his presidency, The New York Times ran its first headline wondering if the weight of his office was already graying Obama prematurely. And what about the extreme case, someone's hair turning white overnight due to a sudden fright? This story's been told about historical figures from Thomas More to Marie Antoinette, not to mention Laura Palmer's troubled dad on Twin Peaks.
There's surprisingly little evidence tying stress to gray hair at all; no clinical study has ever proven a link. But a connection isn't impossible, scientists say. Hair growth is a result of two different kinds of cells in your follicles: keratinocytes producing protein, and melanocytes producing pigment. But keratinocyte stem cells last much longer than melanocyte ones, for some reason, so your follicles can go on producing hair long after they can color it. The process seems to be mediated by stress hormones in some way, so it's at least hypothetically possible that fluctuations in those hormones could produce gray hair at least a few years sooner than you'd expect. Baltimore physician Tyler Cymet, who studies hair-graying, has found that his patients today are going gray five years earlier than they did in 1970, so maybe lifestyle factors like stress, sleep, and diet are the reason.
Overnight, however, is a whole different ball game. Hair cells are dead, as we've learned, and once they're on your head, the pigments aren't going to change unless you change them. Some dermatologists explain stories like Marie Antoinette's by suggesting she had the autoimmune disorder alopecia areata, which causes people to lose hair in patches. It's true that sometime alopecia does attack pigmented hair but leaves whiter hair alone, so that may lead to cases where hair appears to turn grayer in an accelerated period of time, because all the dark hairs fall out. But it's also possible that some French revolutionary saw Marie Antoinette without her wig on for the first time and she wasn't having a great hair day.
Quick Quiz: What CNN newsman has been nicknamed "the silver fox" for his prematurely white hair?