Your own doctor is as likely to be a quack/have quack-like beliefs as you are. Unironically this is true! Better learn to start reading Pubmed!

Doctors/medical associations don't agree with each other on much, even at the very highest levels. For example, the USA and EU have totally different recommendations related to digital rectal exams for aging men. One believes that finding cancer in old men is important, the other claims it's bad because most of those cancers are benign and sticking a finger up an old mans butt often causes its own complications.