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 would like to spit it out. But it turns out that the more sensitive people are to the bitter taste of caffeine, the more coffee they drink, according to a new study. The susceptibility is caused by a genetic variant.
"You would expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee," said the researcher. “The opposing results of our study suggest that coffee consumers gain a taste or an ability to detect caffeine because of the learned positive reinforcement (i.e., stimulation) induced by caffeine.” In other words, people who have a heightened ability to taste the bitterness of coffee - and especially the pronounced bitterness of caffeine - learn to associate "good things" with it.
In this study, people who were more sensitive to caffeine and who drank a lot of coffee consumed a low amount of tea. But that could only be because they were too busy drinking coffee, the researcher noted.
The study also found people sensitive to the bitter taste of quinine and PROP, a synthetic flavor related to the compounds in cruciferous vegetables, avoided coffee. For alcohol, a higher sensitivity to PROP's bitterness resulted in lower alcohol consumption, especially of red wine.
"The findings suggest that our perception of bitter tastes, based on our genetics, contributes to preference for coffee, tea and alcohol," said the researcher.
