Hurts So Good: People Who Perceive More Caffeine Bitterness Drink More Coffee

A group of scientists have discovered that people who are genetically wired to better perceive the bitter taste of caffeine are more likely to drink coffee, despite bitterness having evolved as a warning signal to protect us against consuming harmful substances.

Why? Because they associate the bitter taste of caffeine with the high they get from it. Duh.

“You’d expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee,” Marilyn Cornelis, an assistant professor of preventive medicine at Northwestern’s Feinberg School of Medicine said in a university announcement. “The opposite results of our study suggest coffee consumers acquire a taste or an ability to detect caffeine due to the learned positive reinforcement — i.e., stimulation — elicited by caffeine.”

The study — published today in Scientific Reports and conducted by researchers from Northwestern and from the QIMR Berghofer Medical Research Institute in Australia — gathered data from some 400,000 men and women in the U.K. Biobank.

While compiling the beverage consumption habits of Biobank participants, the study also sought to better understand how genetic variations affect the perception of bitterness as a taste.

“Taste has been studied for a long time, but we don’t know the full mechanics of it,” Cornelis said. “Taste is one of the senses. We want to understand it from a biological standpoint.”

The study measured participants’ response to three types of bitterness: caffeine, quinine and PROP, a synthetic compound often used by scientists to gauge levels of bitter taste perception.

While those people who were more sensitive to quinine and PROP tended to drink less coffee, people who were more sensitive to the bitter taste of caffeine were found to consume more coffee. The reason, Cornelius said, is because they associate “good things with it.”