Debunking "Alternative" Medicine

Half of Americans Believe in Medical Conspiracy Theories

Medical conspiracy theories

An interesting study was recently published in JAMA Internal Medicine by Oliver and Wood (2014). They report the results of a YouGov survey that looked at the acceptance of medical conspiracy theories in the United States and what, if any, effect the belief in medical conspiracy theories had on health-related behavior, such as taking herbal supplements, getting a flu shot and preference for organic foods. The results were chilling as almost half of the U. S. population believed in at least one medical conspiracy. Those who held three or more were less likely to go to the doctor or dentist and fewer got vaccinated against seasonal influenza. They were also more likely to take herbal supplements.

The selection of medical conspiracy theories

Oliver and Wood selected six different medical conspiracy theories to include in their research. Although the researchers did not justify their selection, it seems representative and wide as it spanned from FDA and alternative medicine to discredited beliefs about the origin of HIV.

The Food and Drug Administration is deliberately preventing the public from getting natural cures for cancer and other diseases because of pressure from drug companies.

Health officials know that cell phones cause cancer but are doing nothing to stop it because large corporations won’t let them.

The CIA deliberately infected large numbers of African-Americans with HIV under the guise of a hepatitis inoculation program.

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.

Doctors and the government still want to vaccinate children even though they know these vaccines cause autism and other psychological disorders.

Public water fluoridation is really just a secret way for chemical companies to dump the dangerous byproducts of phosphate mines into the environment.

Some of them, such as the one about Monsanto, seems highly specific and a bit obscure. It is not the most common conspiracy theory about GM crops, which is reflected by the fact that it was by far the least well-known medical conspiracy theory among respondents. At any rate, they managed to capture a wide range of conspiracy theories: cancer quackery, electromagnetic radiation, HIV/AIDS denialism, fearmongering about GM crops, anti-vaccine sentiments and water fluoridation quackery.

The sample size of the study was fairly large (N = 1351) and was deemed representative of the population at large.

Crank magnetism and a culture of conspiracy-mongering

The researchers showed that almost half (49%) of all Americans accept at least one of the medical conspiracies in their survey. The researchers concluded that this means that the belief in conspiracy theories cannot be considered fringe anymore and is not restricted to people with paranoid delusions. Almost one-in-five (18%) accepted three or more. These individuals may constitute evidence of crank magnetism, which is the phenomena that people who believe in some conspiracy theories often believe in multiple ones.

Impact on health-related behaviors?

After controlling for a few confounders such as level of social estrangement, paranoia and socio-economic status, they found some differences in health-related behavior between those that rejected all and those who accepted three or more. The conspiracy addicts were more likely to avoid the medical establishment by not going to the doctor or dentist as often, as well as not bothering to get the flu shot. They were more likely to take herbal supplements and buy food from local producers.

The silver lining?

The proportion of people who rejected a given medical conspiracy theory varied between roughly one-in-three (32%) for “FDA and natural cures for cancer” to a little more than half (51%) for “CIA infected African-Americans with HIV through hepatitis vaccines”. Although these might not be the same individuals, it is still comforting that such a large proportion outright reject this conspiracy theory about HIV.

There is also a considerable proportion of people who did neither agreed nor disagreed for each of the conspiracy theories, ranging from a little less than a third (31%) for “FDA and natural cures for cancer” to almost half (46%) for population control via GM crops. While this may be a knee-jerk response because they were not familiar with that particular medical conspiracy, the data does suggest that there is substantial reservoir of individuals that could be reached and immunized by scientific skepticism. Although this does not by itself imply that they are undecided with respect to other conspiracy theories, there is cause for careful optimism.

Since almost half of respondents accepted at least one conspiracy theory, this means that the other half either rejected all of them or expressed some combination of reject/undecided. It would be interesting to find out what proportion were all-round skeptics and did not believe any of the six conspiracy theories. It would also be interesting to examine how big influence the alleged confounders had. How much more socially estranged are those that accepted 3 or more than those that rejected all? Do they systematically differ in paranoia?

Major conclusions

Oliver and Wood offer two main conclusions: (1) the widespread acceptance of medical conspiracy theories show that they are not the result of paranoid delusions, but of common psychological mechanisms and (2) it might be useful to health care professionals because the belief in medical conspiracy theories correlate with certain anti-medical beliefs, such as avoidance of vaccines and the acceptance of quack treatments.


Oliver JE, & Wood T (2014). Medical Conspiracy Theories and Health Behaviors in the United States. JAMA internal medicine PMID: 24638266


Debunker of pseudoscience.

2 thoughts on “Half of Americans Believe in Medical Conspiracy Theories

  • I have a few concerns with the study.

    Firstly, a very minor concern of mine is the 6th “conspiracy theory.” Disregarding its specificity, I consider any critical reaction to water fluoridation not to be conspiracy, but still falling in the realms of scientific skepticism. I’m entirely convinced that water fluoridation is nothing to be concerned of, but I understand where some people may be coming from with their concerns for it. It’s certainly not on par with HIV/AIDS denial.

    Secondly, this study was carried out by YouGov, which is internet-based and has a preset panel of ~3 million people as a worldwide representative sample. It’s fairly well known that quacktivists and conspiracy theorists tend to flock to the internet most often to have their voices heard, because it’s the way to voice your opinion which faces the least amount of discrimination. That being said, if their panel of 3 million people already has a large percentage of internet activists, or people who spend a significant amount of time on the internet instead of learning the science behind these topics formally, then this sample is probably more representative of the internet population as opposed to the US population as a whole.

    I say all of this, but still, I can’t think of a significantly superior way to carry out such a study of public opinion for more than one conspiracy theory. If this really is a representative study, and close to 50% of Americans believe in at least one of these theories, then I’m truly scared for you and your country (I’m assuming you, the author of this blog, live in America when I say this). Heck, even if only 10% of Americans believed in this stuff, it’d still be worth concern.

  • Thanks for your stimulating comment!

    The study points out that YouGov surveys have been found to be as accurate as surveys given in-person or over the telephone.

    Opposition to water fluoridation is largely a conspiracy theory of the past, peaking during the Red Scare around 1940s/1950s. This may explain why it seems less of a “current” conspiracy theory (i.e. not as easily associated with conspiracy thinking) compared with e. g. HIV/AIDS denialism.

    No, I am not based in the U. S.

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