My favourite remark on this subject is from the Young Ones:
Rick (to hippy Neil): Don't you ever sleep?
Neil: Sleep gives you cancer man. Everybody knows that!
Only slightly less funny, someone has compiled a website listing the Daily Mail's (Brit tabloid scare mongers) attempt to classify absolutely everything known to man as either a cancer cause or cure (and sometimes BOTH at the same time)
http://kill-or-cure.heroku.com/