We all know Superman, right?
In comic books and on television, in movies and even in a Broadway musical, he’s the tights-and-cape-sporting superhero who came to us from the planet Krypton, arriving on Earth with powers and abilities far beyond those of mortal men. (Yes, just men; Superman was born in the 1930s, the pre-feminism age.) These powers involved the ability to travel faster than a speeding bullet, hoist a locomotive one-handed, and leap tall buildings in a single bound. He also had super-intelligence, super-hearing, and X-ray vision. But nobody ever said anything about his ability to taste. Was the Man of Steel a supertaster?
About 25 percent of Americans, it turns out, are. These people have more fungiform papillae—the little mushroom-shaped lumps on your tongue that hold your taste buds–than the norm. While the average taster—about 50 percent of us—usually has somewhere between 15 and 35 papillae in an area 6 millimeters in diameter (about the size of a hole punch), supertasters boast 35-60. Their opposite numbers, known as non-tasters, have less than 15. (Find out which you are by following the instructions below; all you need are a drop of blue food coloring, a magnifying glass, and a friend.)
Supertasters are more sensitive to flavors than the rest of us are. To supertasters, sweet and sour are more intense, capsaicin—the chemical that puts the burn in hot peppers—is positively painful, and mildly bitter flavors that to damped-down, middle-of the-road tasters are pleasant—the edge in black coffee, for example, or the zing in hops-heavy beer—are, at best, off-putting and at worst, repulsive.
Studies of human taste sensitivity began with a lab accident. One fatal day in 1931, Dupont chemist Arthur Fox dropped a bottle of phenylthiocarbamide (PTC), sending a burst of white powder into the air. A cringing colleague commented that the powder tasted disgustingly bitter; Fox, however, who also got a mouthful, could taste nothing at all. Further and better-controlled investigations confirmed that some people—about 70 percent of the population—could taste PTC, while others simply couldn’t. The results, published in 1932 in the Journal of Heredity, included a piece of PTC-impregnated paper so that readers—as early citizen scientists—could test themselves and their families at home. A flurry of PTC studies followed; among the experimental subjects were the Dionne quintuplets. (They could all taste PTC.)
In 1991, psychologist Linda Bartoshuk at Yale University re-visited Fox’s experiments, this time using the related and equally bitter (that is, if you can taste it) 6-n-propylthiouracil (PROP). For those who found PROP unbearably bitter, she coined the term “supertaster.”
Scientists generally identify somewhere between five and twelve different fundamental tastes: sweet, sour, salty, bitter, and umami (savory or “meaty”), plus—possibly—such newbies as calcium, kokumi, piquance, coolness, metallicity, fat, and carbon dioxide (which last puts the sparkle in soda water and champagne). Evolutionarily, our sense of taste developed to steer us toward foods high in nutrition and to warn us off poisons. Children, for example, are drawn to sweets, most likely because at early stages of growth and development, there’s a particular need for high-energy foods. Pregnant women tend to become more sensitive to bitter tastes, presumably to protect vulnerable fetuses from potential toxins.
Taste, however, is a complicated phenomenon: there’s more to it than simply landing a lick of lollipop or a dollop of dill pickle on your tongue. Taste is inextricably entangled with all the other senses: sight, touch, sound, and smell. Foods taste blander if we can’t see them, and sometimes, blinded, our ability to even tell what they are vanishes altogether. Our ability to identify fruit drinks, for example—cherry, orange, lime, grape—turns out to be largely a matter of color. If we can’t see what we’re drinking, we only accurately identify fruit juices by taste about 20 percent of the time. We’re also easily foiled by visual expectations: if fruit drinks are dyed in unusual colors—say, orange juice deceptively colored purple—we tend to think it’s grape. One study showed that people given orange-tinted water cheerfully perceived it as orange-flavored.
Touch, a matter of texture, is often a factor in why people claim to dislike the taste of mushrooms or olives. (Poet Ogden Nash summed this up succinctly in his poem “Eels:” “I don’t mind eels/Except as meals/And the way they feels.”) Sound impacts taste when it comes to crispness and crunch. In taste tests, people find that louder, crunchier potato chips taste better; and nobody likes a squishy crunch-less apple.
The big player in taste, however, is sense of smell. In fact, without smell, most foods don’t taste of anything much. About 80 percent of a food’s flavor, according to one estimate, comes from smell. Furthermore, it doesn’t come from what most of us think of as smell: that is, the satisfying whiff up the nose of frying bacon, simmering soup, or baking bread. Taste is most powerfully impacted by retronasal smell—odors that enter the nasal passages from the back of the mouth, usually as we exhale or swallow.
Our ability to taste drops off with age, In part this is because the number of sensory cells that pick up on aromas in the all-important nose begins to decrease, and in part it’s because we start to lose taste buds as well. In both cases, these cells are in a constant state of turnover—they die and are replaced—but in people post-fifty, the replacement rate slows down to the point where more cells are lost than are regained. Queen Victoria in old age complained that the strawberries weren’t as sweet as they used to be. It wasn’t the strawberries; it was the declining state of the royal nose and tongue.
Supertasters—since they start out with significantly more taste buds than the rest of us—may be more resistant to the taste deprivations of aging. However, being a supertaster isn’t all a bowl of strawberries. Supertasters’ sensitivities can make for picky eaters. They can be overwhelmed by strong tastes—astringent red wine, spicy dishes such as Szechuan chicken or Texas chili—and their low threshold for bitterness may lead them to avoid such healthy, but tangy, foods as broccoli and Brussels sprouts.
When it comes to taste, researchers point out, Superman might be better off if he were… just average.
- Bartoshuk, Linda M. “Comparing Sensory Experiences Across Individuals: Recent Psychophysical Advances Illuminate Genetic Variation in Taste Perception.” Chemical Senses 25, 2000, pp. 447-460.
- Rosenblum, Lawrence D. See What I’m Saying: The Extraordinary Power of Our Five Senses. W.W. Norton, 2010.
- Tepper, Beverly J. and Kathleen L. Keller. “Sensing Fat.” The Scientist, December 2011.
- At Scientific American’s Super-Tasting Science, do this simple experiment to find out if you’re a supertaster.