The last few months of Marie Antoinette’s life would have been terrifying. In 1793, she saw the French monarchy abolished, her husband (King Louis XVI) executed, and her son taken from her as her country descended into violence and bloodshed. Finally, with just one day’s notice, she was taken from her prison cell and condemned to death by guillotine. She was executed, alone, in front of a crowd cheering for her death, just a few short hours later.
That sounds like enough to turn your hair white, doesn’t it? And according to legend, that’s exactly what happened.
“The first time I saw her majesty after the unfortunate catastrophe of the Varennes journey [a botched escape attempt] … she took off her cap and desired me to observe the effect which grief had produced upon her hair,” Marie Antoinette’s lady-in-waiting Henriette Campan later recalled. “It had become, in one single night, as white as that of a woman of seventy.”
Canities subita, or “Marie Antoinette syndrome” as it was dubbed in a 2009 research paper, is about as controversial as the woman herself. Authenticated cases of hair suddenly turning white or gray are extraordinarily rare; some scientists argue that it isn’t possible at all.
“There are no living cells in the hair,” Desmond Tobin, Professor of Dermatological Sciences at University College Dublin, explained to Anne Jolis when her own hair turned white. “Psychosocial stress can’t affect the hair fiber that’s already formed, it can only affect the fibers as they’re forming.”
“It is in fact medically impossible; there is no mechanism by which hair could organically turn white, either suddenly or overnight,” agrees a LiveScience article from 2012. “Even if an illness, injury, or sudden shock could turn hair white, it would be weeks before the effect would be visible because only the root would be affected.”
And yet, history seems full of examples of people going suddenly and prematurely gray after traumatic experiences. There’s the eponymous ex-queen herself, of course; before that, there was Thomas More, an English lawyer whose hair reportedly turned white the night before he was executed by Henry VIII for treason in 1535. The same thing happened to Mary, Queen of Scots before her beheading, as well as a handful of non-famous trauma survivors that made the medical literature.
For a long time, the leading explanation for the phenomenon was a condition called alopecia areata. The idea was that stress could trigger an auto-immune response, causing hair – and particularly pigmented hair – to suddenly fall out. Since unpigmented hair would often be left unscathed, it would appear as though those with the condition had gone gray overnight.
“It’s conceivable for a person who has a tendency for alopecia areata to go through a stressful experience which makes it flair up and the first thing that happens is their dark hair falls out,” dermatologist David Orentreich told NBC News back in 2009. “And that can happen quickly – in days or weeks – leaving just the gray hair.”
“There was only a primitive understanding – if any understanding – of the immune system,” he continued. This lack of knowledge would lead to people searching for reasons like shock or trauma to explain the sudden desaturation, he explained.
But just last year, researchers finally found a mechanism that might explain the phenomenon. In a study published in Nature, researchers exposed mice to various stressors at different stages of hair growth. With each exposure, the researchers found that the rodents’ hair follicles lost the pigment-producing melanocyte stem cells, until eventually the mice were left with patches of Marie Antoinette-esque white fur.
“When we started to study this, I expected that stress was bad for the body – but the detrimental impact of stress that we discovered was beyond what I imagined,” senior author Ya-Chieh Hsu told the Harvard Gazette. “After just a few days, all of the pigment-regenerating stem cells were lost. Once they’re gone, you can’t regenerate pigments anymore. The damage is permanent.”
But the exact process that led to pigment loss was still a mystery. Since the leading hypothesis at the time was the autoimmune theory, the scientists tried stressing out mice with compromised immune systems – but hit a dead end. Equally ill-fated was the investigation into whether the stress hormone cortisol was responsible for the condition.
“Stress always elevates levels of the hormone cortisol in the body, so we thought that cortisol might play a role,” explained Hsu. “But surprisingly, when we removed the adrenal gland from the mice so that they couldn’t produce cortisol-like hormones, their hair still turned gray under stress.”
But the adrenal gland isn’t the only place you can find stress hormones in the body. Having ruled out cortisol as the culprit, the researchers turned their attention to noradrenaline, the main neurotransmitter used by the sympathetic nervous system. This is the part of the nervous system that regulates unconscious action – most of us know it as our fight-or-flight system.
“Acute stress, particularly the fight-or-flight response, has been traditionally viewed to be beneficial for an animal’s survival,” lead author Bing Zhang told the Gazette. “But in this case, acute stress causes permanent depletion of stem cells.”
“[W]e collaborated with many scientists across a wide range of disciplines, using a combination of different approaches to solve a very fundamental biological question,” Zhang said.
So it may well have been grief that turned Marie Antoinette’s hair white after all – and now we know how. Why, though, is another matter – but according to neuroscientists Shayla Clark and Christopher Deppman, who wrote a commentary on the study but were not involved in the research, the answer may lie in some of our closest cousins.
“Because grey hair is most often linked to age, it could be associated with experience, leadership and trust,” they wrote. “For example, adult male silverback mountain gorillas … which get grey hair on their backs after reaching full maturity, can go on to lead a gorilla troop.”
“Perhaps an animal that has endured enough stress to ‘earn’ grey hair has a higher place in the social order than would ordinarily be conferred by that individual’s age,” they suggested.