Misinformation about health and medicine has existed for centuries. Unfortunately, it often seems to spread faster than scientific evidence. These often-bizarre ideas contribute to public opinion and influence real decisions. Ranging from rumors about miracle cures to fears about dangerous vaccines, these theories have had serious negative consequences despite lacking any credible evidence. Understanding where these beliefs come from and why they persist can help us separate fact from fiction.
In today’s social media age, health conspiracies can reach millions of people in a matter of hours. This rapid spread of false information can quickly sweep through online communities. Some conspiracy theories are rooted in historical mistrust or past events, while others come from misunderstandings of complex scientific principles. Still, others seem to come from nowhere but a desire to believe unsettling claims. Despite overwhelming evidence from medical experts, these theories continue to hold sway in certain circles.
To create this list of the most notable medical conspiracy theories, we used information from Nature Medicine, Reuters, NPR, and Frontiers. We also reviewed information about medical conspiracies from the JAMA Network, a medical journal published by the American Medical Association. Here are some of the biggest health conspiracies of all time.
The FDA is withholding the cure for cancer
This conspiracy theory states that there’s already a cure for cancer, but government agencies such as the FDA and pharmaceutical companies are withholding the cure.
This theory has circulated for at least 100 years and has become more popular with the rise of the internet and social media. Many experts have stated that cancer is a complex disease and the FDA has warned against any company that advertises a “miracle cure.”
The government knows cell phones cause cancer
The safety of frequent cell phone use has been questioned many times due to the radio-frequency waves emitted by this type of technology. One theory says that cell phones do in fact cause cancer and the government is aware of it.
While numerous studies have been done to address the potential side effects of long-term cell phone usage, most large health organizations (WHO, FDA, NCI) say there is no clear evidence of increased cancer risk. While radiofrequency radiation can heat tissue at very high levels, cell phones are not found to be capable of producing at these levels.
The CIA infected African Americans with HIV
The CDC first brought attention to the HIV/AIDS epidemic in 1981, which is when the rumors started. This conspiracy theory states that the CIA created the virus to wipe out African Americans.
This belief is often linked to mistrust stemming from real events, especially the Tuskegee Syphilis Study. This notorious undertaking was a long-term U.S. Public Health Service study (1932–1972) in which Black men with syphilis were deliberately left untreated (without informed consent) in order to observe the disease’s progression. This, even after penicillin was available.
Genetically modified foods are part of a secret program by Monsanto
GMOs, or genetically modified foods, have been the subject of numerous conspiracy theories. One of the most-circulated theories involves Monsanto, an agrochemical and agricultural biotechnology corporation.
The theory claims that Monsanto is hiding information that proves GMOs are harmful and that the corporation has infiltrated the FDA and the American Association for the Advancement of Science. Major organizations (WHO, National Academy of Sciences, etc.) generally consider approved GMOs safe, but debate exists about environmental and economic impacts. The prevalence of these theories has led to distrust of any genetically modified ingredients.
The government is hiding proof that vaccines cause disorders
There have been many conspiracy theories and misinformation surrounding vaccines with the most prominent theory being that vaccines cause autism.
One of the first claims of this theory came from Andrew Wakefield, a physician in London, who claimed in the 1990s that the measles vaccine caused autism. Wakefield’s study was retracted and he lost his medical license. These claims have been discredited many times, but this theory is still prominent, especially in online communities.
Public water fluoridation is a way for companies to undermine public health
Water fluoridation is another hot topic. Major health organizations support fluoridation as safe and effective, while opposition persists in some groups. The opposing side argues that water fluoridation violates individual rights and medical ethics.
The conspiracy theory related to fluoridation is a belief that it is intended to undermine public health. In the 1950s and 1960s, it was believed that fluoridation was also a communist plot.
The government is leaving chemtrails that cause health issues
The chemtrail conspiracy relates to the condensation trails left in the air by planes. The theory states that these lingering trails aren’t condensation at all, but actually toxic chemicals the government is intentionally adding to the atmosphere. According to those who believe this theory, the so-called “chemtrails” are meant to control the population, modify the weather, or manage solar radiation.
Despite the various theories about the government’s desire to control us via chemtrails, there is no solid evidence that any are remotely true.
The elite wants people to eat bugs to save the planet
This bug-related conspiracy theory states that the elite want to control the population and force them to eat insects. The theory has circulated in online forums and social media.
After the start of the COVID-19 pandemic, the bug theory morphed into something greater. Believers of this theory stated that COVID was being used by the elite as a cover-up to control the population and make them eat insects.
The CIA developed the polio vaccine to sterilize men
There are numerous conspiracy theories surrounding the polio vaccine. One of the theories claimed that the vaccine was created by the CIA in an attempt to sterilize men. Some versions of this theory also include Bill Gates and state that he funded a polio vaccine that disabled thousands of children.
Conspiracy theories about the polio vaccine are prominent in the Middle East, mainly due to an immunization campaign created by the CIA in 2011 to find Osama bin Laden (however, that campaign did not involve polio vaccines directly; it used a fake hepatitis B campaign).
The US military imported COVID into China
In recent years, many of the medical conspiracy theories that have circulated are related to the COVID-19 pandemic. Many of the theories surrounding the virus sought to make China responsible.
However, a spokesman for the Chinese foreign ministry, Zhao Lijian, initially spread a theory blaming the U.S. for importing COVID into China.
COVID-19 doesn’t actually exist
Another conspiracy theory that circulated during the pandemic was that COVID-19 never actually existed.
This theory stated that it was a secret plot by the elite to take away individual freedoms and control citizens. While this theory started circulating at the beginning of the pandemic, many still believed it after the virus had spread extensively.
Wealthy elites intentionally spread COVID-19 to win power
Other COVID-19 conspiracy theories were circulating during the pandemic as well. One of these theories claimed that the wealthy elites were manipulating the pandemic.
Some believed that there was a secret plot to undermine the president. Additionally, they believed that Dr. Fauci, former medical advisor to the administration, was a part of this secret plot. During a press meeting, Dr. Fauci denied the ridiculous connection, but it didn’t convince those who bought into this theory.
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