A new survey revealed that about half of all Americans believe at least one medical conspiracy theory.
Some of these theories are more widely believed than others; about three times as many people believe U.S. regulators prevent patients from receiving natural cures than think that a U.S. spy agency purposely infected a population of African Americans with the human immunodeficiency virus (HIV), Reuters reported.
"Science in general - medicine in particular - is complicated and cognitively challenging because you have to carry around a lot of uncertainty," University of Chicago's .J. Eric Oliver, who led the study, told Reuters. "To talk about epidemiology and probability theories is difficult to understand as opposed to 'if you put this substance in your body, it's going to be bad."
The researchers surveyed1,351 American adults. They were given six popular conspiracy theories and asked whether they did or did not agree with them. Other conspiracies included the idea that "the government knows cell phones cause cancer but does nothing about it, that genetically modified organisms are being used to shrink the world's population, that routine vaccinations cause autism and that water fluoridation is a way for companies to dump dangerous chemicals into the environment," Reuters reported.
Forty-nine percent of the participants were found to agree with at least one conspiracy theory. Thirty-seven percent of the participants agreed that regulators are withholding natural cures. Sixty-nine percent of the respondents had heard of the conspiracy theory that vaccines cause autism and 20 percent believed it.
"Although it is common to disparage adherents of conspiracy theories as a delusional fringe of paranoid cranks, our data suggest that medical conspiracy theories are widely known, broadly endorsed, and highly predictive of many common health behaviors," the researchers write in JAMA Internal Medicine, Reuters reported.
"It's important to increase information about health and science to the public," Oliver said. "I think scientific thinking is not a very intuitive way to see the world. For people who don't have a lot of education, it's relatively easy to reject the scientific way of thinking about things."
