A huge and complex topic. As you might know, I write a blog on veterinary medicine, largely trying to debunk myths about alternative therapies, and I contribute to the Science-Based Medicine blog, so this subject takes up a great deal of my time and energy. It is hard to summarize it briefly, but I’ll try to answer your specific questions, and I’ll include links to more detailed discussions.
“Complementary medicine” is really an ideological label designed to suggest that unproven or already disproven therapies can add benefits to conventional medicine. It partly replaced “alternative medicine” because promoters of that weren’t having much luck getting most people to give up scientific medicine and replace it with alternative therapies, so they decided to change their marketing to tell people they could use both. Lately, “integrative medicine” has become the most popular term, since it suggests alternative and science-based therapies are equivalent and should be treated as the same, rather than treating science-based medicine as the main therapy and other approaches as “complementary.”
None of this has anything to do with the evidence for or against particular treatments. “Complementary and Alternative Medicine” (or CAM, as it is often called for short) is a label applied to everything from valid scientific practices like regular exercise and a healthy diet, which CAM advocates like to claim are their idea, to complete voodoo like homeopathy and Reiki. The function of the label is largely to exempt individual therapies from the standards of evidence science-based medicine uses to test treatments.
As for Dr. Oz, he is widely regarded as a charlatan who has gradually drifted from legitimate medical practice to selling snake oil on TV. Most doctors who are not CAM advocates see him as an embarrassment to the profession. Here are some links to discussions of how he is viewed from a science and evidence-based perspective.
All that said, sadly the integrative medicine propaganda is having an impact on conventional medicine, and more and more mainstream doctors and medical schools are incorporating unproven therapies into their practice. The reasons for this vary from money (lots of research dollars and sales to patients/clients) to politics (encouragement from well-meaning but misguided as well as outright bought politicians) to a desire to make patients/clients happy. Some doctors really do believe in the value of these therapies despite the lack of good research evidence, of course, because after all doctors are not immune to the allure of anecdotes, cognitive biases, and other faulty reasoning that makes unproven or bogus therapies seem effective. That is as true in veterinary medicine as in human healthcare, and I actually just wrote about the issue here.
As for acupuncture, this one is complex also. There are thousands of studies on acupuncture, with all possible results. The best evidence, with the best controls for bias and error, suggest that acupuncture improves subjective symptoms like pain and nausea, but no more than well-performed fake acupuncture. That would mean it is essentially an elaborate placebo, as has been argued in a recent editorial in the journal Anesthesia & Analgesia. It clearly has biological effects when you stick needles into the body, but the balance of the evidence suggests these effects are not predictable or controllable, they are not specific to the problem being treated or the manner in which the needling is done, it doesn’t make any difference where you put the needles, and overall it is not much different biologically from stubbing your toe or getting a bunch of paper cuts. However, the ritual of acupuncture does have a strong effect on how people perceive their symptoms, so it will feel like it’s working even if it isn’t changing objectively measurable aspects of your disease. This might have some value, though it comes at the cost of letting people believe it is something more than a placebo.
For animals, however, the way the placebo effect works is quite different, and likely acupuncture is only making owners and veterinarians feel better, not the animal patients. I wrote a blog post for the JREF Swift blog on placebos in veterinary medicine recently which talks about this in detail. In brief, apparent placebo effects do occur in research studies because the effects we call “placebo effects” actually include a number of factors that make a fake therapy look like it’s working besides just people’s beliefs. However, for the most part the placebo effect in veterinary medicine works on owners and vets rather than on patients, so we end up thinking we’ve helped when really the patient’s condition is no better. This is why we have to be especially careful to be sure our therapies in vet med really work according to scientific standards. Otherwise, we face a great risk of imagining our treatments are working while our patients continue to suffer.
I hope this is helpful, Lois. Obviously, I can give you a lot more detail if you want, especially on the veterinary side of things. And you can always check out my blog for that, and the Science-Based Medicine Blog for the perspective in human medicine.