I know, I haven't come across alzheimer's jokes, but would definitely be upset if i did.
I think it is a British thing to make jokes about taboo subjects, and there were masses of dark jokes at a human rights organization I worked in. Some people use it as a kind of stress release, but I think it really isn't meant in a 'nasty' way. Of course it is upsetting for certain people and I know just how bad it can be if you are feeling sensitive. I think it can feel a bit like being rude about family...it seems totally ok to make jokes about your own family, but the minute someone from 'outside' does the same you feel outrage. You may sound flippant and as if you don't care, but when someone is apparently rude about a loved one (with whom they may have no close connection)it makes the blood boil (or the tears flow!).
I don't honestly know whether 'rising above it' or confronting head on is better.
peppa