It may not be necessary to perk you up, either.
If you've ever had the feeling that food doesn’t taste quite as flavorful after drinking a cup of coffee, new research backs you up. Caffeine may actually subdue taste buds, making food taste less sweet—meaning that if you drink a cup of caffeinated coffee with your breakfast it can change how the meal tastes.
The study, published in the Journal of Food Science, had 107 participants drink different types of coffee to measure their reaction to the caffeine: Half of them drank sweetened decaffeinated coffee with caffeine added back in (so that the scientists had a control group), while the other half drank sweetened decaffeinated coffee with added quinine (also found in tonic water) to mimic the bitter taste caffeine would typically bring to coffee.
The participants reported that the caffeinated coffee tasted less sweet than the decaf coffee with the added quinine, and that after drinking it, sugar tasted less sweet. The researchers say this points to caffeine actually changing how your taste buds perceive flavors.
“I think the fact that you may be changing how your food tastes if you drink it with coffee is an interesting offshoot of this,” one of the study’s authors, Robin Dando, told Gizmodo.
The study also turned up about another surprising finding: The researchers had their subjects record how alert they felt after drinking each type of coffee, both caffeinated and decaffeinated. They reported the same degree of alertness after drinking each type of coffee, and when asked to predict which type of coffee they drank, they couldn’t tell the difference between the two.
"We think there might be a placebo or a conditioning effect to the simple action of drinking coffee," Dando said in a statement. "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.”
The scientists aren't saying this means caffeine just has a placebo effect on people. For now, they speculate that merely the act of the drinking coffee could be all that matters if you want to wake yourself up on a sluggish morning.
"What seems to be important is the action of drinking that coffee," Dando explained. “Just the action of thinking that you've done the things that make you feel more awake, makes you feel more awake."
Next time you're at the café to pick up your morning boost, you might want to try a cup of decaffeinated coffee (it might have the same effect on your energy level) and think twice about ordering that sticky-sweet doughnut on the side. If Dando and his team are right, it just won't taste quite as good anyway.