Summary: Researchers report caffeinated drinks reduce our ability to taste just how sweet something is. Ironically, this makes us crave sweet tastes more.
Source: Cornell University.
Caffeine, the widely consumed stimulant and igniter of sluggish mornings, has been found to temper taste buds temporarily, making food and drink seem less sweet, according to new Cornell University research.
Caffeine is a powerful antagonist of adenosine receptors, which promote relaxation and sleepiness. Suppressing the receptors awakens people but decreases their ability to taste sweetness — which, ironically, may make them desire it more.
The research demonstrates taste modulation in the real world, said senior author Robin Dando, assistant professor of food science: “When you drink caffeinated coffee, it will change how you perceive taste — for however long that effect lasts. So if you eat food directly after drinking a caffeinated coffee or other caffeinated drinks, you will likely perceive food differently.”
Dando, along with lead authors Ezen Choo and Benjamin Picket published, “Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste,” in the Journal of Food Science.
In the blind study, one group sampled decaffeinated coffee with 200 milligrams of caffeine added in a laboratory setting, making a strong cup of coffee. The stimulant was added to make that group’s coffee consistent with real-life amounts of caffeine. The other group drank just decaffeinated coffee. Both groups had sugar added. Panelists who drank the caffeinated brew rated it as less sweet.
In a secondary part of the study, participants disclosed their level of alertness and estimated the amount of caffeine in their coffee. Further, panelists reported the same increase in alertness after drinking either the caffeinated or decaffeinated samples, all the while panelists could not predict if they had consumed the decaffeinated or the caffeinated version.
“We think there might be a placebo or a conditioning effect to the simple action of drinking coffee,” said Dando. “Think Pavlov’s dog. The act of drinking coffee – with the aroma and taste – is usually followed by alertness. So the panelists felt alert even if the caffeine was not there,” said Dando.
“What seems to be important is the action of drinking that coffee,” Dando said. “Just the action of thinking that you’ve done the things that make you feel more awake, makes you feel more awake.”
Source: Joe Schwartz – Cornell University
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste” by Ezen Choo, Benjamin Picket,and Robin Dando in Journal of Food Science. Published online August 23 2017 doi:10.1111/1750-3841.13836
Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste
Multiple recent reports have detailed the presence of adenosine receptors in sweet sensitive taste cells of mice. These receptors are activated by endogenous adenosine in the plasma to enhance sweet signals within the taste bud, before reporting to the primary afferent. As we commonly consume caffeine, a powerful antagonist for such receptors, in our daily lives, an intriguing question we sought to answer was whether the caffeine we habitually consume in coffee can inhibit the perception of sweet taste in humans. 107 panelists were randomly assigned to 2 groups, sampling decaffeinated coffee supplemented with either 200 mg of caffeine, about the level found in a strong cup of coffee, or an equally bitter concentration of quinine. Participants subsequently performed sensory testing, with the session repeated in the alternative condition in a second session on a separate day. Panelists rated both the sweetened coffee itself and subsequent sucrose solutions as less sweet in the caffeine condition, despite the treatment having no effect on bitter, sour, salty, or umami perception. Panelists were also unable to discern whether they had consumed the caffeinated or noncaffeinated coffee, with ratings of alertness increased equally, but no significant improvement in reaction times, highlighting coffee’s powerful placebo effect. This work validates earlier observations in rodents in a human population.
Adenosine receptors are present in taste buds. This report examines how caffeine present in our diet may act on these receptors, altering the perception of sweet taste. Our results suggest that we may be altering our perception of the foods we consume through our consumption of caffeinated foods and beverages.
Panelists were also unable to identify if they had consumed caffeinated or noncaffeinated coffee, highlighting the powerful placebo effect of coffee consumption.
“Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste” by Ezen Choo, Benjamin Picket,and Robin Dando in Journal of Food Science. Published online August 23 2017 doi:10.1111/1750-3841.13836