One drizzly Thursday evening a few weeks ago, I dyed my tongue blue.
As the tiny dot of food coloring spread gradually across the expanse of twitching muscle, I commended myself for sacrificing looks in the name of scientific discovery.
Photo by Marissa Angell
For the previous few days, I’d been reading about the science of taste, and the differences between people scientists once called “supertasters,” “tasters,” and “nontasters.” Intrigued by the possibility that my oral anatomy might earn me superhero status, I asked the entire Greatist Team to participate in an experiment to learn more about our sensory perception.
There was a hole puncher, paper towels for blotting leakage, and more than a few hesitant glances around the room as we closed our computers and gathered over the table full of equipment.
The test is simple: Punch a hole in a piece of wax paper, dab some blue food coloring on the tongue, place the wax paper over the tongue, and count the number of little white dots visible in the hole. Most people will have between 15 and 25. Those above and below the average are known as supertasters and nontasters, respectively.
Taste the Rainbow — Why Differences in Taste Sensitivity are Important
The terms supertaster, taster, and nontaster generally describe sensitivity to the bitter-tasting chemical 6-n-propylthiouracil, or PROP. About half the human population is made up of “tasters,” or those with average taste sensitivities. The rest is divided between nontasters, who tend to be less sensitive to the taste of food, and supertasters.
Linda Bartoshuk used the term supertaster for the first time in 1991 to describe people with the most taste buds. Today, the word is a general term for people who demonstrate heightened taste and oral sensation, according to John Hayes, a professor of food science at Penn State University. Sometimes, the term describes the response to PROP. Over the past 20 years, supertasters have gained something like celebrity status. The Lady Gagas of science, they can’t help their refined palettes— baby, they were born this way.
As catchy as supertasting and nontasting might sound, scientists have started relying less on these labels. Human tongues— even those that can’t unwrap a Starburst— have 25 different receptors for bitterness alone. So, just because someone’s a supertaster doesn’t mean he/she is supersensitive to all bitter tastes. But it does mean they’re more susceptible to certain health problems.
Differences in taste sensitivity amount to more than just whose face looks least attractive while eating a lemon. Studies suggest people highly sensitive to bitter tastes are more likely to develop colon cancer because they avoid vegetables with protective flavonoids (which tend to taste bitter) Association between 6-n-propylthiouracil (PROP) bitterness and colonic neoplasms. Basson, M.D., Bartoshuk, L.M., Dichello, S.Z., et al. Department of Surgery, Wayne State University, Detroit, Michigan, USA. Digestive Diseases and Sciences, 2005; 50(3): 483-9.. Other research suggests women who are less sensitive to the taste of fat are more likely to be obese.
Given the link between taste sensitivity and health issues, some scientists say people should learn more about their tastebuds. Researchers at the Monell Chemical Senses Center in Philadelphia are working to develop a standardized taste test— one that doesn’t involve swishing and spitting the contents of a bottle of Merlot. The initiative is part of the NIH Toolbox for Assessment of Neurobiological Function, an effort to create new ways to measure sensation and other biological functions. Right now, a typical medical checkup in the USA involves hearing and vision tests. But Danielle Reed, a researcher at the Monell Center, believes taste testing “should be a part of normal medical testing.”
Current research into taste may also pave the way for personalized nutrition therapy. Ideally, educating people about their sensory perception won’t give them get-out-of-vegetables-free cards. Nutritionists might suggest less repulsive foods with the same health benefits. When I spoke with Hayes over the phone, he was adamant about humans’ ability to overcome genetic predispositions: “Biology is not destiny.”
But biology can still be an important factor in food preferences, especially the taste for bitterness. According to Hayes, people with one variant of a certain bitterness gene eat 25 percent fewer vegetables than people with another version of the same gene. Kids are especially partial to sweet tastes, and it typically takes years before they move on to bigger, bitter things.
Reed suggests the avoidance of bitter foods may serve an evolutionary function, since bitter tastes once signaled dangerous foods. And while most people haven’t scavenged in a forest of potentially poisonous plants since Gilligans’ Island went off-air, the human body hasn’t yet caught on. In other words, most children are genetically programmed to avoid foods that are good for them. Encouraging kids to swap pasta for peas is, Reed says, “fight[ing] … basic biology.”
The link between taste sensitivity and body weight still isn’t clear Genetic variation in taste perception: does it have a role in healthy eating? Feeney, E., O'Brien, S., Scannell, A., et al. UCD Institute of Food and Health, School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Republic of Ireland. The Proceedings of the Nutrition Society, 2011; 70(1): 135-43.. But, for women, taste sensitivity seems to be a good predictor of weight patterns. Middle-aged women whose tongues lead them toward tubs of Ben & Jerry’s tend to have greater body mass indexes than those who’ve got the urge for herbal tea Adiposity in middle-aged women is associated with genetic taste blindness to 6-n-propylthiouracil. Goldstein, G.L., Duan ,H., Tepper, B.J. Rutgers University, Department of Food Science, Cook College, New Brunswick, NJ. Obesity research, 2005; 13(6): 1017-23. Genetic variation in taste perception: does it have a role in healthy eating? Feeney, E., O'Brien, S., Scannell, A., et al.UCD Institute of Food and Health, School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Republic of Ireland. The Proceedings of the Nutrition Society, 2011; 70(1): 135-43..
In general, genetic and environmental factors work together to produce a person’s preference for certain foods PROP taster status and self-perceived food adventurousness influence food preferences. Ullrich, N.V., Touger-Decker, R., O'sullivan-Maillet, J., et al. Department of Food Science, Rutgers University, New Brunswick, NJ. Journal of the American Dietetic Association, 2004; 104(4): 543-9.. Lisa Moskovitz, a NYC-based dietician (and a Greatist Expert!), says, “People eat foods according to how they make them feel afterward.”
Coffee is a good example: Genetics influence people’s perception of coffee’s bitterness, but they don’t necessarily explain how much people like the beverage. Hayes says these findings show the “role learning plays in overcoming innate dislikes” Allelic variation in TAS2R bitter receptor genes associates with variation in sensations from and ingestive behaviors toward common bitter beverages in adults. Hayes, J.E., Wallace, M.R., Knopik, V.S., et al. Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, PA. Chemical Senses, 2011; 36(3): 311-9..
The first step toward proper nutrition may be getting in touch with the tongue. Moskovitz helps clients create meal plans that include foods they find satisfying. “Otherwise,” she says, “they won’t be happy and probably won’t stick with the changes.”
Tip of the Tongue — The Results
I stuck out my tongue and waited, the awkwardness slowly evaporating, as another Greatist staffer leaned in to count the number of dots she could see. After years of wading teary-eyed through jars of “mild” salsa, and spitting out cherry Dots that tasted like Tylenol, I couldn’t believe my delicate palette was anything less than supertasting.
“Eleven,” she announced with conviction.
I demanded she recount (as thrilling as my tongue is, she declined) and considered the possibility that my tongue was more stoic than I could have imagined. Neither a superhero nor a regular Joe— a nontaster.
But after learning more about the science of taste, I gradually left my disappointment behind. Instead of focusing on the anatomy of my tongue, I wondered how many vegetables I’d eaten in the past week. I thought about the possibility that current research could help millions of people achieve better health. The idea seemed exciting.
Though I wouldn’t be averse to counting my taste buds one more time— just to be certain.