I've known people, myself included, that have had negative health impacts from coffee, so that could be biasing my perspective. My father nearly died from heart complications after coffee, I bleed at the exit 100% of the time I drink coffee. I love coffee, but I can't drink it. There's probably something genetic that makes my line intolerant. I know people that end up in a migraine caffeine withdrawal cycle on a regular basis. Obviously these are person specific, so you really just need to know your body and act accordingly.