by Matt Siegel
Just like in the stories, our fantasies of Cockaigne were too good to be true.
“We always knew that having what you wanted didn’t make you likeable,”95 writes Elizabeth Farrelly in Blubberland: The Dangers of Happiness. “Now we know it doesn’t make you happy or successful either.”
Chapter 9
Forbidden Berries (or Appetite for Distraction)
Healthy, sane humans do not stab themselves in the thighs,1 or bathe their eyes in lemon juice. So why do we so love to assault one of the most sensitive organs in the human body, the tongue, with what amounts to chemical warfare?
—Jason G. Goldman
Humans, as we’ve seen, like to eat a lot of strange things—pigeon pies, rendered bear fat, tiny ancestors of corn, sugar of lead, pigs sewed together with chickens, and fire-breathing peacocks—yet perhaps even stranger is our taste for chili peppers: a fruit*23 that, ecologically speaking, specifically evolved to repel us.
You see, whereas corn developed that tough outer casing to protect its seeds and other berries developed thorns, chilies developed a chemical defense mechanism in the form of capsaicin, the principal function of which is to cause predators pain.*4 The industry term for this is directed deterrence. Birds, which are natural seed dispersers and excrete seeds whole and intact, are immune to capsaicin, a biological reward for helping chilies spread and propagate. And this mutualistic relationship extends even further than just birds air-dropping seeds with piles of natural fertilizer in the form of their droppings. Explains culinary historian Maricel E. Presilla, the journey through a bird’s intestinal tract not only camouflages seeds from seed-eating predators but also eliminates some seed-destroying funguses;5 as a result, seeds excreted by birds have nearly 400 percent better odds6 of surviving in the wild.
Meanwhile humans, whose mammalian teeth tend to crush and destroy seeds, making us an ecological threat to chilies, can sense capsaicin at less than one part per million.7 In contrast, the human threshold for sensing salt (sodium chloride) begins at about two thousand parts per million8 and sugar (sucrose) around five thousand. And it’s not our sense of taste that’s doing the work here, as is the case with things we perceive as salty, sweet, sour, bitter, or umami, but rather our trigeminal or chemical sense,9 which registers sensations of irritation, temperature, and touch to alert the body of potentially harmful chemicals and bacteria. In fact, the same pain sensor that alerts us to capsaicin, TRPV1,10 also responds to physical heat, specifically temperatures above 109°F. So eating a pepper isn’t unlike, say, being stung by a bee, licking a nine-volt battery, or burning your tongue on scalding hot coffee—all sensations intended to warn the body of exposure to harm and if necessary trigger a series of protective reflexes11 to mitigate the effects and prevent further exposure.
Bite into a habañero or order your food “Thai hot,” and your body essentially thinks it’s being attacked by a chemical weapon. Beyond the burning pain, which is supposed to compel you to reject or eject spicy food, you’ll probably begin to sweat as your body attempts to flush your system; your nose will run to protect your nasal passages; your eyes will water to protect your corneas; you’ll produce excess saliva to purge your mouth; and you might cough or sneeze to protect your airways—a lot of the same defense mechanisms you’d expect if you were to eat something you were allergic to or choke on a pretzel.
In contrast, foods that nature actually intended us to eat tend to elicit positive reflexes, such as triggering the production of stomach acid or pancreatic hormones. Explains Gary K. Beauchamp, emeritus director and president of the Monell Chemical Senses Center in Philadelphia, “The traditional view of taste receptors12 is that they have to do with conscious perception and food selection,” helping us differentiate between quality food sources and potentially hazardous poisons or bacteria. However, taste receptors also exist downstream in places like the gut and airways*13 to screen for criteria we’re not completely conscious of (nutrients, calories, proteins) and help regulate satiation and digestion.
And this deterrence isn’t limited to humans. Capsaicin is an effective threat deterrent almost unilaterally, from predatory insects and rodents to seed-destroying funguses.14 In lieu of electric fences (which are cost prohibitive and no match for elephants with nonconductive tusks),15 some farmers in Africa plant chilies16 along the barriers of their farms, mix chili powder with motor oil and smear it on fences, burn bricks of chilies and dried elephant dung,17 or throw condoms filled with chilies and firecrackers to keep elephants away from their crops.*
Ranchers smear capsaicin on sheep to keep wolves away18, manufacturers have put it in wallpaper adhesive to ward off rats19, and some carmakers have started wrapping electrical wires with capsaicin-infused tape20 to keep rodents from chewing them (a problem that may have been exacerbated by the switch to soy-based wiring, which smells similar to vanilla when heated). Chili-flavored birdseed is also a thing and is used to prevent squirrels from pilfering bird food.
Capsaicin has even been used underwater to keep mussels from attaching to boat hulls21, and natives of the San Blas Islands22 off the coast of Panama allegedly drag lines of chilies behind their canoes to repel sharks—though there’s little evidence this is effective, as numerous attempts by the US Navy to develop chemical shark deterrents23 have found that even those that are strong enough to kill sharks generally fail to deter them from eating the bait before dying.*24
And similar uses apply to humans. In the 1960s, two professors at the University of Georgia developed pepper spray as an animal repellent,25 which was initially used by postal workers and meter readers to defend themselves against dogs but was quickly adopted by joggers and law enforcement for defense against other humans; mothers apply capsaicin to their breasts26 to initiate weaning or to children’s thumbs to stop the habit of thumb-sucking;27 and in the 1980s, some New York City transit employees sprinkled chili powder on turnstile slots28 in hopes of keeping teenagers from sucking out used subway tokens,* a practice that could net the vandals up to one hundred dollars a day—at the time equivalent to about thirty hours of minimum wage.29
Yet humans are the only animal stubborn enough to seek out this pain by putting hot sauce on our eggs—and it’s not for a lack of trying to convert others.
Repeated attempts to induce a preference for chili peppers in rats,30 including gradually lacing their food with capsaicin, inducing sickness whenever they ate food without it, and provoking thiamine deficiency, then nursing them back to health with capsaicin in their recovery food, have failed, suggesting that rats have an innate aversion to capsaicin that disappears only upon destroying their senses. In all scenarios the rats showed a clear preference for foods that didn’t burn them and an aversion to those that did, leading researchers to conclude, “One cannot fail to be impressed by31 the resistance shown by laboratory rats to the acquisition of a preference for chili pepper.”
And neither can one fail to be impressed by the resistance shown by humans to physical pain and our own biological distress signals.
Ironically, our stubborn pursuit of chilies has taken them further than birds ever could.*32 They’re now the most commonly used spice in the world, where they’re grown on every continent (if we count a greenhouse in Antarctica33 designed to test plant cultivation technologies developed for human space exploration) and eaten daily by roughly a third of the global population34, making up such staple components of regional cuisines as North African harissa, Korean gochujang, Thai sriracha, Indonesian sambal, and American Flamin’ Hot Cheetos. More than six thousand years after first cultivating them,35 we’re still spreading them like wildfire—and selectively breeding them to be even more potent, creating entirely new varieties like the Carolina Reaper, reportedly up to four hundred times as hot as jalapeños.36
So clearly, our attraction to chilies wasn’t just a phase; the heart wants what the heart wants—which is, apparently, frequent heartburn.
The Aztecs probably captured the inanity of this best. They revered
chilies and ate them with every meal37, going without them only during periods of ritual fasting (sort of the Aztec equivalent of sacrificing meat during Lent), and used them medicinally to treat everything from eye infections to labor pains38. Their cure for acne? Wash your face with chili powder and hot urine. And, yet, they also used them for ritual punishment, rubbing chilies on the genitals of misbehaving children39 or holding their children over piles of burning chilies40 to choke and suffocate them with the fumes.*41
Of course, our oral sadism isn’t just limited to capsaicin. “The majority of adults in the world ingest,42 every day, at least one innately rejected substance,” write Paul Rozin and Deborah Schiller.
Consider the bitterness of dark chocolate and coffee, the latter of which people often enjoy at temperatures high enough to cause tissue damage43; the caustic burn of alcohol and wasabi (or cigarettes) in the throat and nasal passages; the pins and needles of soda or champagne carbonation, caused by carbonic acid; or the astringency of black tea and dry wine. Like chilies, these are all innately unpalatable to the uninitiated—and there’s no scientific consensus as to why we consume them.
Probably the simplest explanation is to pin things on food preservation, as chilies also happen to kill bacteria44 and mask the taste and odor of foods that aren’t the freshest. This would explain why spicy foods tend to be more prevalent in hotter climates,45 where higher temperatures make food preservation more challenging, places like Central America, southern Asia, and Indonesia. And the same idea extends to the use of spices in general. When researchers at Cornell University analyzed nearly five thousand recipes from thirty-six countries, they found that the number of spices per dish increased alongside the average annual temperature46 of the region—and that cultures in warmer climates tended to use not just more spices in their dishes but specifically those with the strongest antibacterial potency, the average spice inhibiting around 67 percent of bacteria47 compared to 80 percent inhibited by chilies.48 (Surprisingly, sour acids such as lemon and lime juice inhibited a mere 24 percent.49)
So chilies may have helped preserve food before the age of refrigeration and may also have functioned as a primitive form of air-conditioning, as the gustatory sweating meant to flush the body of capsaicin also has a cooling effect50 that helps regulate body temperature, which helps explain why people eat vindaloo in India and pad prik king in Thailand.
Meanwhile, people in arctic or subarctic regions tend to eat foods that are higher in fat content, such as whale meat or akutuq, an Alaskan dish of whipped caribou fat, seal oil, and berries51, often referred to as Eskimo ice cream, as well as fermented foods such as sauerkraut, fermented seal oil, or decomposed Icelandic shark meat that’s been buried underground for months and marinated in lactic acid (described by Anthony Bourdain as the single worst thing52 he had ever put in his mouth, which is significant coming from a man who had eaten Namibian warthog rectum). The fat, of course, provides energy, and the fermentation, similar to capsaicin, provides another low-tech way to inhibit pathogens53, yielding a lot of the same benefits of cooking (e.g., softening foods and breaking down or predigesting fats and proteins) without sacrificing valuable fuel.*
It could also be that eating chilies helps us cope with other types of pain, both physical and emotional, similar to the mechanisms of watching sad movies, running marathons, or scratching insect bites54 to the point of tissue damage—forms of self-inflicted torture that not only provide tangible distractions from real-world pains (in essence, giving us something else to cry about) but also trigger the release of feel-good chemicals that help block and suppress pain,55 one of the reasons distance runners experience a “runner’s high.”
John Launer, a physician who has suffered from eczema his whole life, similarly describes how eczema sufferers will sometimes plunge their hands into near-boiling water to stop the itching. “Only hot water close to boiling point56 will crack it,” he says. “Almost everyone with eczema knows this.”
This helps explain why capsaicin is a common ingredient in over-the-counter topical pain treatments57 for things like arthritis, sore muscles, and joint pain—and why the Aztecs used chilies as an anesthetic58 during childbirth.
As with childbirth, we tend to forget the intensity of pain from chilies once the initial sensations have faded,*59 leading us to continually burn our mouths after vowing never to do so ever again—yet another relic of evolution designed to ensure the fate of the species by encouraging individual risk. “The evolutionary advantages of this convenient amnesia60 are obvious,” explain Terry Burnham and Jay Phelan, “and all of us who are not the first-born in our families should be thankful.”
Those of us popping prescription-strength antacids as a result of capsaicin, maybe not so much.
Another theory is that our habit of eating spicy food evolved as a method of peacocking, i.e., displaying bravado and masculinity in order to attract mates by showcasing an ability to protect them. Indeed, research shows a correlation between a preference for spicy foods and testosterone levels61 as well as personality constructs associated with the pursuit of money, sex, and social status,62 particularly among college-age males.
Anyone who has ever been to high school, of course, knows that hypermasculine bravado and self-inflicted harm are hallmarks of teenage citizenship used to establish social hierarchies. Back in Aztec times, coming-of-age adolescents were given pulque, a beerlike beverage made from fermented agave sap, and held over fires to mark their transition63 from youth to adulthood, symbolizing their transformation from “raw” to “cooked.” Meanwhile, some modern cultures practice similar coming-of-age rituals, such as walking over hot coals or enduring toxic insect bites, giving new meaning to “toxic masculinity.” Writes Chip Brown in National Geographic, “Mardudjara aboriginal boys in Australia64 are expected to swallow their own foreskins,” “Sambia mountain boys in Papua New Guinea push sharp sticks into their nostrils to make their noses bleed and have to swallow semen after oral sex with young men,” and “Satere Mawe boys in the Brazilian Amazon insert their hands into gloves filled with bullet ants (Paraponera clavata) whose neurotoxic sting is said to be among the most agonizing in nature.”
Here in the United States, of course, teens just pierce and tattoo themselves, assault one another’s senses with AXE body spray, and challenge one another to eat spoonfuls of cinnamon or Tide pods on social media—which are really just modern versions of the intercollegiate goldfish-swallowing competitions of 1939,65 which started out at Harvard and quickly spread across the country.*
It’s also possible that humans turned to chilies out of boredom and a desire to escape their monotonous routine through “the seeking of varied, novel, complex,66 and intense sensations and experiences, and the willingness to take physical, social, legal, and financial risks for the sake of such experience.” This, according to psychologists who place chilies in the same category as things like scuba diving, binge drinking, gambling, and sexual nonconformance.
This would explain why astronauts in orbit almost universally tend to crave spicy foods like hot sauce,67 cocktail sauce, and wasabi. Granted, microgravity plays a role here, too, by causing a swelling of the tongue and nasal passages that blocks a lot of the pathways to taste receptors, mimicking the effects of a head cold and leading astronauts to seek out stronger flavors—or, in the case of chilies, stronger chemical sensations. But boredom likely plays an equal or greater role,68 given the time astronauts spend performing repetitive tasks while floating in sterile, colorless environments deprived of the senses of home.
The military faces a similar struggle when it comes to feeding soldiers in the field. Granted, military rations have come a long way since the canned biscuits, unmeltable chocolate bars,69 instant coffee, and Spam*70 of World War II (even though, in some ways, we’ve gone backward since the days of the American Revolution, when rations included things like beer, cider, whiskey, and rum).71 Today’s MREs (“meal, ready-to-eat”) include foods like pepperoni pizza, smoked almonds, an
d instant cappuccinos72 with a choice of Irish cream, French vanilla, or mocha, but they’re still a far cry from the comforts of home, which aren’t typically formulated to be dropped out of helicopters, consumed from self-heating plastic pouches, or endure years of extreme weather. So, surviving on rations alone can be quite boring, which is why, depending on whom you speak to, MRE also stands for “Meals Rejected by Everyone.” It’s also why Tabasco sauce has become a preferred condiment of soldiers,73 with so many carrying it on them in the field to combat the monotony of long deployments that, beginning in Iraq in 1990, the US military started officially issuing miniature glass bottles of it with meals, later switching from glass to ketchup-style packets to cut down on weight, breakage, and manufacturing costs. More recently, they’ve also added menu items like jalapeño cashews, packets of crushed red pepper, and jalapeño ketchup.74
Cultural psychologist Paul Rozin, a legend in the study of human food selection and avoidance who coined the term benign masochism75 to describe our attraction to chilies and other “initially negative experiences76 that the body (brain) falsely interprets as threatening,” similarly likens the attraction of chilies to that of roller coasters and horror movies, the idea being that we crave not just varied and complex sensations but the thrill of simulating danger and the rush of pushing ourselves to our limit.
Notes Yale professor of psychology Paul Bloom, “Some teenage girls enjoy cutting themselves77 with razors; some men pay good money to be spanked by prostitutes.”
“It’s not that we like78 [these experiences] despite the pain,” explains Bloom. “We like them, at least in part, because of the pain.”
In fact, it’s not just horror movies that chilies are similar to but movies in general—dramas, action movies. Think about all the kids’ movies with plots involving dead parents, evil villains, and perilous quests: Bambi, Peter Pan, Ratatouille, Harry Potter . . .