Most doctors are not research doctors and do not stay on top of the all the studies out there. They basically go off of what they learned in school and during their internships and what they pick up in practice, so listening to your doctor's advice is likely hearing what the thinking was 20 years ago when they were in medical school. Plus, there is a ton of money in the system trying to convince everyone must be on drugs. Hint--if you are signing your check at the doctor's office on a blotter that advertises a drug, and there is a poster in the examination room on the wall, and your doctor has a pocket protector from the company be very wary of accepting a prescription for that drug! It's like going into a Goodyear store for your car and asking for an unbiased opinion on tires--you're not going to get it.