In my opinion, its rude. Some girl doctor asked me the same thing too. Its like there only intention is to build a case against you. I don't believe that any of these doctors that I've seen in my life time (of the ones I remember) actually care about my health. They just can't wait for someone to say "yes," so then they could blame every health problem in the world for the rest of your life on juice. Besides, I don't even use anything.
And oh yea, I was at the dentist 2 weeks ago. This was my second time at his office and I knew something didn't feel right about him during my first visit, at least his attitude directed toward me. Well, the second visit I went to get fillings and he must have gave me much more local anesthetics than needed because it puffed up my whole face and I couldn't even breath. They started giving me oxygen...I'm so lucky I didn't collapse. Well, then they start asking me if I take any recreational drugs or stuff for bodybuilding and to make a long story short I think he was writing some stuff about an anxiety attack causing this to save his ass. I hate these bastards.