The human tongue is an organ that enables us to enjoy the sense of taste. And on the tongue lies those bumps that we call our taste buds, which makes eating chocolate so pleasurable and ice cream so indulgent.
This week on “Take Care,” hosts Linda Lowen and Lorraine Rapp talk to Dr. Linda Bartoshuk about how those taste buds work and why people have different tastes than others. Dr. Bartoshuk is the director of human research at the University of Florida Center for Smell and Taste, and is the scientist behind the groundbreaking discovery of supertasters -- individuals who have stronger reactions to taste than most of us.
A common misconception is that the actual bumps seen on the tongue are the taste buds themselves.
“Taste buds are actually not the structures you see on your tongue,” Bartoshuk says. “Those are papillae. The ones that contain taste buds are called fungiform papillae.”
On these fungiform papillae are a bunch of small dots that are not visible to the naked eye. These dots are holes that serve as a sort of channel opening that lead down into the taste bud cells, buried in the tissue of the tongue.
“Magnified, the taste buds look like a little orange, the different segments being the cells of the taste buds,” Bartoshuk says. “These cells extend to the top into tiny filaments called microvilli. These little filaments stick up into the bottom of that channel and that’s where taste comes in contact with them.”
The filament extensions have taste receptor sites bonded to them. So when food comes into contact with the tongue, a bit of it goes down this channel, hits the microvilli and stimulates one of the sites. These sites include sweet, sour salt and bitter, but also can include umami, which is a pleasant savory taste, and even fat.
“Once the food and site bind, they set up an electrical discharge along a nerve, and it’s that discharge that goes up to the brain and tells the brain that some chemical like sugar has bound to one of your taste receptor sites,” Bartoshuk says.
While taste buds are present in all people, they are not all designed the same. There are also variations in the number of taste buds each person has. Some tongues might have fungiform papillae scattered throughout the tongue and others may have them “wall to wall across the tongue,” which Bartoshuk says, are the “supertasters” that she’s been studying, people that have much more intense taste. Being a supertaster can result in having different experiences during eating and drinking.
“You have two people, a supertaster and somebody who’s not a supertaster sitting across the breakfast table, tasting ordinary common sugar,” Bartoshuk says. “The supertaster is going to taste two, maybe three times as much sweet. That’s big enough to affect food preferences. And that’s where those of us who are in research get interested. Because, if your food preferences vary, your diet varies, and now we’re looking at variations in risk factors for disease.”
Supertasters might also be less willing to eat things like spicy food, because each taste bud is connected to a pain filter. The more taste buds one has, the more pain filters there are, so supertasters receive more of a burn.
However, Bartoshuk also points out that people’s preferences to things like spicy food “depends much more on experience than biology.” Super tasters can experience that burn sensation, but learn to like the burn. After all, people who eat hot chili peppers eat them because they like them. Non-super tasters might like them or dislike them, depending on their own experiences. In the end, super taster or not, it still comes down to an individual’s matter of taste.