Why do we like the bitter taste of coffee? Bitterness evolved as a natural warning system to protect the body from harmful substances. By evolutionary logic, we should want to spit it out.
But, it turns out, the more sensitive people are to the bitter taste of caffeine, the more coffee they drink, reports a new study from Northwestern Medicine and QIMR Berghofer Medical Research Institute in Australia. The sensitivity is caused by a genetic variant.
“You’d expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee,” said Marilyn Cornelis, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine. “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.”