I don't know about grapefruit and caffeine specifically, but it's at least a great example from a tongue-in-cheek perspective. Grapefruit has a kind of ridiculo

I don't know about grapefruit and caffeine specifically, but it's at least a great example from a tongue-in-cheek perspective. Grapefruit has a kind of ridiculously long list of drug interactions. It seems like pretty much everyone I know over the age of 65 is under doctor's orders to stay away from it. https://www.fda.gov/consumers/consumer-updates/grapefruit-juice-and-some-drugs-dont-mix https://www.fda.gov/consumers/consumer-updates/grapefruit-ju...