According to legend, Marie Antoinette went completely gray on the night before she was executed by beheading. While a graying as rapid as that may not be very plausible, most people seem to believe that stress can precipitate the hair on our heads turning from its natural color to white, or gray.
But is there any factual basis for this common belief? Well, yes. But not all the facts are in just yet.
Just as soot and water combine to create the scent of a rose, just two types of pigment are needed to produce the many shades and colors we find in human hair from jet black hair color to bright red. They are yellowish red melanin and black or dark brown melanin. This is the same substance which creates different skin tones, and your hair does have to share your body’s melanin supply with your skin.
Along the shaft of your hair follicles is a cluster of cells called the bulge, which produces melanin. The melanin is then passed down to the specialized cells at the base of the follicle which produce keratin. As the hair is produced at the base of the follicle, the keratin is pigmented with the melanin to give you the distinctive hair color that you are familiar with.
The keratin is naturally colorless. It is the same protein that is used to produce the nails on your fingers and toes.
As we age the pigment cells attached to our follicles will become less active. There appears to be a kind of setting that each person’s pigment cells are preset to which determines how long they will continue to produce the color for your hair. Each person begins to gray at around the same time- between the ages of 35 to 45. But some people fall outside of this normative range for reasons that are probably best explained by genetics. For the best estimate of the age at which you are likely to turn gray, ask your parents when they started losing their hair color. Barring injury and extreme stress, this is the best predictive factor.
Going gray usually doesn’t begin all at once- and certainly, hairs do not suddenly turn white overnight. Even if the supply of pigment was suddenly cut off completely, the hair would still have to grow out to start showing grayness.
Rather, graying will happen gradually as the pigment cells slowly begin to curtail their function. Eventually, these cells will die off entirely- at which point all of the keratin emerging from your scalp in the form of hair will be free of pigment and appear white.
Certain lifestyle choices and environmental factors can accelerate the graying process. Exposure to toxins, poor nutrition, smoking, and certain types of injuries can accelerate the process. Iron deficiencies and thyroid problems can also cause or exacerbate the graying process.
But What About Stress?
A lot of people report having gone gray after a stressful or traumatic event, but is there any scientific data to back that up? This is an area of human biology that is pretty difficult to research. After all, it would be pretty unlikely to get funding and ethics approval for a study involving intentionally inducing high levels of stress on human subjects. That’s the kind of thing you would expect to see in a Monty Python sketch.
There have been studies done on mice which do, in fact, seem to show that stress can cause premature graying. In 2013, some of these studies seemed to suggest that it was the presence of high levels of stress hormones that appeared to precipitate the early graying of hair in mice. What was found is that mice with high levels of stress hormones like cortisol, had their pigment cells migrate away from the hair follicles, resulting in white hair growth.
Researchers also believe that an overabundance of stress hormones can disrupt the signals that trigger pigment cells to deliver pigment to the keratin producing cells at the base of the follicle. This second factor could take place without the pigment cells needing to die off- making graying hair harder to predict.
But these studies do seem to offer some pretty compelling evidence to support the belief that stress can cause gray hair. Of course, while these studies are compelling- they have not been conducted on humans- which means that according to science, the jury is still out. Nevertheless, many people will reasonably conclude that the results found in these mice studies are indicative of what happens to human hair color after a prolonged period of stress.
But to achieve these results from a sudden trauma, it would be necessary to prove that a single event caused the production of melanin to stop abruptly. This would seem unlikely and would be even more difficult to prove in clinical trials. However, it is likely that people will continue to believe that a single terrifying event can cause our hair to turn completely gray overnight.
Gray Hair Facts
The most important factor in predicting the appearance of your first gray hairs is genetics.
When the skin is damaged, by a burn, for example, pigment cells will migrate away from the hair follicles to replenish the pigment in the skin. This can result in a patch of gray hair at the affected area.
In many cultures, gray or white hair has been seen as a status symbol, denoting distinction or wisdom. Oiling and powdering the hair was popular in the 18th century. And dying the hair blond has always been popular in recent decades.
Rare autoimmune disorders can cause patches of gray hair to emerge. This is really the only plausible way to explain events like what happened to Marie Antoinette- although we’re pretty sure she just didn’t powder her wig on the morning she was executed.