October 27, 2021 – Sweetie treats may not be so easily made to like sugar-free treats, thanks to taste buds wired to look for candy with calories, a new study suggests.
The taste isn’t just about choosing cups of peanut butter over jelly candies. Since early mankind, our sense of taste has helped us detect salty, sweet, sour, salty, and bitter so that we can choose foods that are high in energy and low in poisons.
But these new findings suggest that our taste buds have another hidden talent: identifying foods that don’t give us any energy.
Scientists suspected this ability after research on mice showed that their taste buds could distinguish between sugar and artificial sweeteners with no calories.
To test this possibility in humans, the scientists asked people to drink a series of clear drinks and identify whether they were plain or sugary water. The goal was to compare people’s reaction to glucose – a natural calorie sweetener found in fruit, honey, and table sugar – and sucralose, a calorie-free artificial sweetener.
All participants wore nasal plugs, ensuring that they would only use their taste buds and not their sense of smell for detection.
As expected, people could easily distinguish plain water from sugary drinks, whether with glucose or sucralose, confirming that taste buds detect sweetness.
In a twist, the researchers then mixed in tasteless chemicals that prevent the taste buds from picking up the sweetness. With these drinks, people could no longer distinguish sweetened sucralose drinks from plain water. But they could still tell when they had a drink sweetened with glucose.
This finding indicates that two distinct pathways underlie the mouth’s response to sugar, report researchers in PLOS One. The first path identifies sweet flavors and the second detects foods that contain energy that can be used as fuel.
Scientists may one day come up with calorie-free candies that trick taste buds to detect the presence of calories, thus improving their appeal. But in lab studies, participants had no visual or olfactory cues to guide their reactions, meaning it’s unclear how these other sensory inputs would affect the perception of the treatment.