Take a look at photos of a president — any president — at the beginning and the end of their terms. What do you notice?
They all look a whole lot older at the end of their service, complete with new wrinkles and plenty of grey hair. Part of that is just due to aging; they are four or eight years older after their presidencies end, after all.
But does this happen because of the job? Does stress cause grey hair?
How does grey hair happen?
Most of us start seeing grey strands pop up around 30 (if you’re a guy) and about 35 (if you’re a woman), but family genetics means that some people can begin greying — or even just greying in certain areas — in high school.
By the same token, some people won’t ever go grey, thanks to genetics.
The actual greying process starts deep inside our hair follicles — all 100,000-plus of them. In those follicles, epidermal cells called keratinocytes build by stacking on top of each other and eventually dying, leaving keratin behind.
Keratin is colorless, but gives our hair (and skin and nails) texture and strength. As hair grows, another group of cells known melanocytes creates melanin that comes in two colors — dark brown or black (eumelanin) and yellow or red (pheomelanin) — and combines to create our hair colors.
Grey hair doesn’t have that melanin, so when a hair goes from an active growth phase to a resting phase it falls out before the process starts again. However, keratinocytes live longer than melanocyte cells, so the hair still grows, but without the pigment it had before.
But does stress cause grey hair?
Stress hormones might impact melanocytes, dermatologist Jennifer Lin told Scientific American.
"There is evidence that local expression of stress hormones mediate the signals instructing melanocytes to deliver melanin to keratinocytes," she told the magazine. "Conceivably, if that signal is disrupted, melanin will not deliver pigment to your hair."
“There has been debate over the relationship between the lack of vitamin B [and the presence of grey hair], and low vitamin B can be influenced by stress,” Sandra Gilman, trichologist and educational director for The Elan Center for Trichology, added to The Huffington Post.
Trauma can cause hair changes, like greying
Another thing that can impact the growth of greys: disruption due to trauma, surgery and other nutritional deficiencies.
“As the hair grows out of the follicle, various processes take place in a timely fashion to produce a shaft of hair with the correct color (genetically speaking),” Gilman said. “One of these processes involves the melanin-producing cells that are present and whose job it is to provide color to the hair during the hair-growth cycle. During this cycle, anything that interrupts the flow of events can cause the non-pigmentation of the hair shaft.”
So while there’s not a 100 percent guarantee that stress can cause grey hair, we can say with certainty that grey hair depends on genetics — and there’s no one-size-fits-all answer. It might just be that we notice presidents — and celebrities — aging because they’re in the public eye and we see them more often and they would’ve gone grey during that time regardless of their job and stress level.
Celebrities. They’re just like us.