We’ve all seen the Before and After photos of American presidents. All the men who’ve served two terms in recent years have come out of the White House a lot grayer than when they went in. But is stress really to blame? And how does stress affect hair color for us regular folks? 

To figure that out, we first need to understand how hair works. Imagine your scalp is a factory. The product—the hair that you see and brush every day—is a tube of dead cells. It’s pushed up continuously through your scalp by your hard-working follicles. Part of this work involves making pigment in cells called melanocytes. The follicles of a healthy young person generally churn out brown, black, blond, or red hair without a problem. The robust machinery of their melanocytes can fend off a damaging process called oxidative stress (in this case, “stress” means cellular and not emotional strain).

But this, like all things, is temporary. By the time we hit our 20s and 30s, our follicular factories will start to show signs of wear and tear. The genes that fight oxidative stress begin to falter, which allows oxidation and its products to get a foothold. As oxidative compounds like hydrogen peroxide accumulate in our follicles, our melanocytes weaken and die. Facing a pigment shortage, our follicles begin to make colorless hair instead. Other changes in the factory affect the new gray hair’s texture, making it coarse, wiry, and more brittle than its pigmented predecessors. 

To find out where stress fits into the picture, we spoke with dermatology consultant Miri Seiberg, who has spent more than 20 years researching hair and skin. She said that stress can lead to a grayer appearance—just not typically the way we imagine. “Stress is more likely to cause hair loss and to increase shedding,” she told mental_floss via email, “rather than cause graying.” 

But there are exceptions. Although oxidative stress and emotional stress are not the same thing, they are connected. “A very strong, chronic stress is known to increase oxidative stress,” Seiberg says, “and there are studies that document correlations between extreme emotional stress and increased cellular oxidative stress. This is not to say that we gray every time we fight with our children or spouses.” 

The stress she’s thinking of is much more extreme. “History records that the hair of some condemned prisoners (e.g. Thomas More, 1535, and Marie Antoinette, 1793) turned white overnight before their executions,” Seiberg says. If these stories are true, the condemned were likely affected by a disease called diffuse alopecia areata, which affects 1 percent of people and can cause half of a person’s hair to fall out in a matter of hours. Since they’re more likely to shed dark hair, people with this condition who already have salt-and-pepper hair can appear to go gray or white overnight. 

Other medical conditions, environmental factors, and habits can also increase your odds of going gray earlier or faster. Smokers are four times more likely than non-smokers to go gray prematurely, as are people dealing with malnutrition or prolonged exposure to air pollution. 

So why do our presidents go gray in office? Because they’re middle-aged adults and they, like the rest of us, keep getting older. But the stress certainly doesn't help. 

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