It seems that caffeine and therefore coffee can have a neuro-protective effect for Parkinson’s people.
CDC site article on Parkinson’s, Genomics and Coffee:

Here’s a guy who probably won’t be getting PD, if coffee and nicotine protect one against Parkinson’s. (I drank a lot of coffee in my day, but quit smoking early, after getting strep throat and then bronchitis within the course of a few months. Figured my body was trying to tell me something.)