Did you ever notice that all fast food joints have the same "smell"? Hot oil mixed with eau de onion? Some people have even half-jokingly suggested there may be a secret addictive chemical pumped in.
"[The sense of taste] is in a bad way," Steven A. Witherly, PhD, president and CEO of Technical Products Inc., a food consulting firm in Valencia, Calif., tells WebMD. "Fast food has ridiculously high levels of salt, fat, and sugar -- and the brain likes salt, fat, and sugar."
Everyone has about 10,000 taste buds on his or her tongue (although these may thin as people grow older). "Fast food does not so much dull the taste buds as affect how the brain processes that taste as pleasurable or unpleasant," Witherly says. Hormones such as insulin and leptin also affect the brain's impression of a given food. "Snack food is affecting how we process food."
Sense of Taste Deceptively Simple
Traditionally, scientists have said the sense of taste can detect salty, bitter, sour, and sweet. Now, Witherly says, a fifth taste found to be directly received by the tongue is umami (pronounced "ooo-mommy"), which is the monosodium glutamate (MSG) taste. Parmesan cheese is huge on this, 1% by weight; soy sauce is also 1%. Umami is tied to a protein found in breast milk that the brain is attracted to.
Witherly also says the human sense of taste can recognize the hot pepper taste and another he calls the fatty acid taste.
Marcia Levin Pelchat, PhD, a psychologist and research scientist with the Monell Chemical Senses Center in Philadelphia, tells WebMD the hot pepper taste is more of a skin irritation signal in the inner cheek rather than a taste. (Carbonation, she says, provides a similar irritation that can be studied by taste researchers.)
Whatever triggers them, your sense of taste picks up the signal and sends it to the brain for interpretation and combination with other tastes.
Certain sensations -- like salt, sugar, and to some extent, the sensation of fat -- become an expectation. People want to experience them. "I have seen people's brain scans light up in the pleasure centers when fat passes over their tongue," Witherly says.
In fact, researchers at Yale University, led by Linda A. Bartoshuk, PhD, have discovered that about 35% of white women and 15% of white men are "supertasters," people with an exaggerated sense of taste, compared with the rest of us mortals. These souls inhabit a more limited food universe because their sense of taste is so much more intense. For one thing, they tend to eat fewer bitter vegetables, the kinds that are thought to ward off cancer. On the good side, supertasters also spurn fatty foods more often and thus develop less heart disease.
"Fast food," Bartoshuk tells WebMD, "does not physically affect taste buds, but it may affect appetite and food preferences."
Learned Eating Behavior
Why can no known salad hold a candle to a basket of waffle fries for some people? Whether a person's sense of taste prefers salty or sweet may be genetic, Pelchat says. A recent study in Pediatrics showed that these preferences may be built starting at birth. Babies fed with soy formula (bitter and sour) were more tolerant of sour taste and aroma than kids who slurped down the bland, cereal-tasting formula more often fed to babies. Babies also showed a preference for tastes that came through in the mother's breast milk.
Monell also studies sense of taste in twins, seeing if they end up with the same preferences. But which sensitivity would trigger which reaction is the question. "You might think someone with more bitter receptors would end up hating bitter," she says, "but that isn't always the case."
Witherly says the more overweight people are, the more their response to sugar is blunted. "You need more and more to get the same high," he says. Incidentally, another study, done at the Smell & Taste Treatment and Research Foundation in Chicago, showed that putting intense-tasting substances called "tastants" on food caused dieters to lose more weight than those who ate unamped portions. The tastants, researchers speculated, may have made the dieters feel full sooner.
"People like that they are used to," Pelchat concludes. "If you are used to tastes high in sugar and salt, that is what you expect."
From Ridiculous to the Sublime
The Sept. 6, 2004, issue of The New Yorker was devoted to stories and articles rhapsodizing about food and its potentially seductive intricacies. For example:
- "There is damn little contentment in humanity today," said one organic farmer. "And most of that is because our food has no contentment itself."
- This same farmer brews vats of nutrient "teas" made of crushed oyster shells, sea salt, volcanic rock, and molasses and sends it through his irrigation systems. Some days, he sends the plants an infusion of lavender. "A plant doesn't wear dark glasses or anything," this man is quoted as saying. "It will just sit there in its nakedness and show you how it's feeling."
- In another article, the science of ketchup is painstakingly outlined. Even this fast food staple contains high science and maddeningly subtle variations of mouth and nose sensations.
Rejuvenating Your Sense of Taste
According to Witherly, people can break the fast food, smushy, always-the-same habit. "I don't say get off salt and sugar cold turkey," he says. "But how about just getting off refined sugar, sucrose, and especially high-fructose corn syrup? These increase insulin and lead to fat storage."
Other suggestions to aid your sense of taste:
- Don't give up carbs, but do stick with complex carbs like whole grains and beans.
- Don't be afraid to use artificial sweeteners. They can increase endorphins.
- Try to cut back on salt. At least don't salt before tasting. Or take the shaker off the table. In a week to a month, tops, your old level of saltiness will taste terrible to you.
- Try salt substitutes such as Parmesan cheese, yeast extracts, or soy sauce.
- The body craves variety; fast food places don't have enough of it. Some people know the menu by heart. Try for high-volume foods, like salads, that fill you up with less calorie density.
- Kick the saturated fat habit. Most commercial fries are sizzled in beef fat. Stick with olive oil, fish oils, and flax oils. These are less likely, Witherly says, to be stored as fat in the body.
- And eat slowly. There is even a movement called Slow Food devoted to langorous eating.
One more tip: Skip the fast food and treat your sense of taste to a mozzarella-tomato-basil sandwich. Fields of greens are out there sipping on lavender tea in the sparkling sun. They are waiting for you.
"If only we could be transported to Paris," Pelchat says with a sigh.