Some of the conspiracy theories include:
- Vaccines cause autism
- Cell phones cause cancer
- The FDA is deliberately preventing access to natural cancer cures
- The use of GMOs in food is a program designed to shrink the world population
To give examples of concrete issues with these views, if a patient believes that there is a natural food out there that will cure him of cancer, and meanwhile refuses to accept chemotherapy, there will be a real consequence to that person and his family. Unfortunately, that consequence could come too late for it to be useful as a learning experience to that patient. I have not heard of a situation in which this is happening en masse, however. The anti-vaccine mamas, however, are, as a group, taking a path that not only puts their own babies at risk, but those children and adults who are not able to be vaccinated.
In a more abstract sense, would trying to change these views by any means lead your patient to distrust you, and do more damage to the situation than good? I feel this is extremely likely, and this secondary danger may be even more dangerous than the first situation. It certainly depends on the patient.