When an astronaut spends enough time in a zero-gravity environment, they get what NASA calls the 'Charlie Brown' phase. Their head begins to swell, because liquids that are usually dragged down by gravity stay in their head.
As a result of this, astronauts begin to lose the sense of smell. They feel like they have a cold, stuffy nose, etc. And they can't really taste things very well. The head of NASA's food science program thinks that losing the ability to taste leads to astronauts craving hot things like Tabasco because that way they can at least feel something different in their taste buds.