Many people find their first taste of black coffee is bitter, but later they enjoy it. Scientists at the University of California, San Francisco, did a study to understand why this happens. They discovered that the brain can learn to like a taste if the body feels good after drinking or eating it.

The scientists found a link between the stomach and the brain using a messenger chemical called dopamine. This chemical helps with learning and motivation. The study, done with mice, showed that when the animals got calories from food or sugar, a long message went from their stomachs to their brains. This taught the brain to connect a certain taste with feeling full or getting energy.

The researchers say this process may be why some people start to enjoy the taste of coffee, even if they did not like it at first. Scientists hope this discovery will help them learn more about how people choose which foods they like, but more research is needed.