Capsaicin triggers TRPV1 receptors, the same ones that are primed to recognize temperatures above 104 degrees Fahrenheit, a baseline that may qualify as a brutal summer day but is not quite hot enough to fry an egg on the sidewalk or literally burn you. (In 2016, a case was reported of a man whose esophagus ruptured after he ate ghost peppers, among the most ferocious of chiles, but doctors determined that this was caused by retching and vomiting in response to the pain brought on by capsaicin, not by the capsaicin itself.) Scientists used to describe this effect as “irritation,” which seems a slightly dismissive word for the trembling sweats caused by too many habaneros (100,000 to 892,700 Scoville Heat Units) or the near-death experience of the Carolina Reaper, known to reach as many as 2.2 million S.H.U.s — more potent than some pepper sprays — and certified by Guinness World Records as the hottest chile on earth. Since 1990, our sensitivity to such substances has been called, less chidingly, chemesthesis.
But how can we properly describe an experience that is essentially a trick of the mind, a false cry of fire? It’s only an illusion of heat, and still we weep. After one significantly capsaicin-heavy meal, “I had to lie down because I felt high from it,” the American flavor scientist Arielle Johnson says. (Her book, “Flavorama: The Unbridled Science of Flavor and How to Get It to Work for You,” is due out next year.) The blessing is the aftermath, when a strange euphoria can set in, akin to the flooding of endorphins. Maybe eating chiles is a kind of catharsis, voluntarily putting ourselves through suffering in order to come out the other side, to restore our faith in a happy ending.
Notably, the more chiles we eat, “the less it hurts,” says Johnson, 35. Our minds stop insisting, “This is pain,” so we can pay more attention to actual taste, noticing, maybe for the first time, all the other flavors chiles bring to a dish, relegating flame to the backdrop.
From the perspective of evolution, capsaicin is a weapon, enabling chiles to thwart predators. The British cultural critic Stuart Walton, writing in “The Devil’s Dinner” (2018), points out that the hotter peppers are less vulnerable to fungus, which likely made them attractive to our primal ancestors as a food that stayed fresh longer. (It helped that chiles turned out to be vitamin rich, as well.) And because birds are unaffected by capsaicin, they could blithely eat chiles and then unknowingly disseminate the seeds, supporting not just the peppers’ survival but their proliferation — and, eventually, their conquest of the world.
For unlike the coveted spices of old like cloves and cinnamon, chiles didn’t require tropical environments to flourish. They weren’t anchored to a place that had to be pillaged and controlled; instead, they grew easily in their new homes, which meant they couldn’t be reserved for the rich or monopolized by traders as a high-priced rarity. So chiles never conferred status; rather, they eluded the capitalist system of value. A food of the people, they were adopted by commoners in Asia and Africa who ate them perhaps simply because they liked them.
In an added benefit, some cultures viewed chiles’ fervent properties as curative. Traditional Chinese medicine has long advocated ingredients that evoke heat, to help you sweat out and expel dampness — the fog that settles within, obstructing blood flow and leaving you achy and lethargic. And what have we lived through the past two years but a time of dampness, of blurred, soul-depleting days and stasis? Could chiles be the prescription for our age? “What is culture,” Johnson asks, “but a sensory experience you share with people around you?”