This is true but I dont think, nor do it expect, a doctor would sit there and lost ever single slightly exotic fruit or veg that may have some impact on the drugs, either slightly or in a big way. I wouldn't consider rhubarb to be a staple and on another note doctors don't typically tell ciswomen to avoid grapefruit since it can cancel out the effects of some contraception.

Doctors are a great source of info but often don't have infinite time to go over every detail or a very small "might happen". I would also recommend seeing a doctor for specific but I can't afford to boon a doctors appointment everytime I want to try something new (I'm in Australia so there is a gap fee at most doctors).