6 popular medical conspiracies

I've always loved a good conspiracy theory. And, as Consumer Reports' chief medical researcher, being skeptical about health claims and medical interventions is part and parcel of the work I do. I'm also—yes, I admit it—a huge fan of a well-designed survey. Combine those things and I'm in heaven—which is why I'm so taken with a study out this week that looked at six popular medical conspiracies and what people's belief in them says about their other health habits.

Researchers from the University of Chicago's political science department surveyed 1,351 adults nationwide to determine the extent of "medical conspiracism" (my new favorite phrase!) in the U.S. The study was published this week in the journal JAMA Internal Medicine. Shown below are the percentage of people surveyed who agreed with the following statements.

• 37 percent say the U.S. Food and Drug Administration is deliberately preventing the public from getting natural cures for cancer and other diseases because of pressure from drug companies.
• 20 percent say doctors and the government still want to vaccinate children even though they know these vaccines cause autism and other psychological disorders.
• 20 percent say health officials know that cell phones cause cancer but are doing nothing to stop it because large corporations won't let them.
• 12 percent say the CIA deliberately infected large numbers of African Americans with HIV under the guise of a hepatitis inoculation program.
• 12 percent say the global dissemination of genetically modified foods by Monsanto Inc. is part of a secret program, called Agenda 21, launched by the Rockefeller and Ford foundations to shrink the world's population.
• 12 percent say public water fluoridation is really just a secret way for chemical companies to dump the dangerous byproducts of phosphate mines into the environment.

Yes, it's interesting that so many Americans believe those things. But without getting mired in the details of each controversy, what really fascinated me was how belief in those conspiracies correlated with other health habits.

For example, "high conspiracists" were less likely to use sunscreen, get an annual flu shot, or see a dentist or doctor on a regular basis. They also tended to rely more on vitamin and herbal supplementation and purchase organic and locally grown food. (Full disclosure: I think buying local and organic food makes a lot of sense, but relying on vitamin and herbal supplements? Not so much.)

As the authors of the study note, it's easy for many of us to just laugh off conspiracy theories "as a delusional fringe of paranoid cranks," but most people who endorse these conspiracies are just normal folks. After all, over the years industry, our government, and some medical researchers have given us more than a few reasons to doubt that they always have our best interest in mind.

Still, the evidence is pretty strong that adhering to several of those medical conspiracies, such as not vaccinating your children, can compromise your health and that of those around you. And in my experience, you can usually get a good sense of a claim's validity by digging into the research. Are the claims backed by published, peer-reviewed studies, and coming from reputable sources?  So sure, have a healthy skepticism about medical claims. I do: It's part of my job. But be particularly dubious about the unsubstantiated ones, such as those you see on talk shows or late night TV being pitched as the newest weight-loss supplements or products touted as designed to extend your longevity.

—Chris Hendel