A “staggering” number of people believe unproven claims about vaccines, raw milk and more.

More than two-thirds of the population believe at least one false or unproven health claim, such as the idea that taking paracetamol during pregnancy causes autism. new investigation find. The findings suggest that a large, and potentially growing, number of people are questioning the scientific evidence.

The survey, of more than 16,000 people in 16 countries, asked whether they believed claims not supported by research, including that “the risk of childhood vaccinations outweighs the benefits,” “fluoride in water is harmful” and “raw milk is healthier than pasteurized milk.”

For each claim, between 25% and 32% of respondents said they believed it, and another significant percentage (17% to 39%) said they didn’t know if it was true. In total, 70% of those surveyed believed at least one of the statements. The findings, which have not been peer-reviewed and were published today by the Edelman Trust Institute in New York, were described as “staggering” in an accompanying article written by the think tank’s chief executive, Richard Edelman.

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The result “explodes the idea” that such beliefs are only shared by a marginal population of poorly informed or ideologically motivated individuals, says David Bersoff, research director at the Edelman Trust Institute. “It’s not like a small, problematic group.”

“There are certainly a growing number of people who are questioning widely accepted scientific evidence,” agrees Heidi Larson, who studies vaccine trust at the London School of Hygiene & Tropical Medicine. “It’s important to pay attention to it.”

Controversial claims

Other recent studies have highlighted how often people question scientific consensus or evidence-based medical practices, at least in some controversial areas, such as vaccines. A 2023 global study found that during the COVID-19 pandemic, people’s confidence in the importance of vaccines for children fell in 52 of 55 countries.

This year, a KFF investigationa nonprofit health policy research organization in San Francisco, California, found that 34% of adults in the United States thought it was definitely or probably true that taking Tylenol (acetaminophen) during pregnancy increased the child’s risk of developing autism, even though scientific evidence does not support this link.

This claim, and a few others mentioned in the Edelman investigation, were supported by US Secretary of Health Robert F. Kennedy Jr and the broader Make America Healthy Again movement. But the study’s findings suggest that these beliefs extend far beyond the United States. In most countries surveyed – including Brazil, South Africa, India, Germany and the UK – at least 50% of respondents believed one or more “controversial” health claims.

People who believed three or more statements were as likely to have attended college and more likely to look up health information than those who believed less. This challenges the assumption that people who hold such views are misinformed, Bersoff says.

The real problem, he argues, is the overabundance of conflicting information, from social media, the news and real-life peers. In a British survey published last weeknearly 40% of respondents agreed that there is “now too much information available to know what is true about science.”

Redistribution of trust

Research suggests that, generally speaking, public trust in science and scientists remains relatively high. In the United States, 77% of adults in 2025 said they had confidence in scientists to act in the public interest, according to a study. Pew Research Center surveya think tank based in Washington DC. This is significantly higher than the proportion saying they have confidence in business leaders (37%) or elected officials (27%), although down from 86% in 2019, before the COVID-19 pandemic.

But people increasingly trust information from other sources, researchers say. “I think what we’re seeing is perhaps a redistribution of that trust” away from scientific institutions, says Colin Strong, head of behavioral science at market research firm Ipsos in London. The Edelman survey showed that a high proportion of people value personal recommendations and social media influencers as sources of health expertise, as do people with college educations.

“There has been a proliferation of ‘experts’ and trusted voices, and as a result, the expertise of scientists has been somewhat diluted,” Bersoff says. “The more experts there are in your world, the more likely it is that on one or more occasions you will stray from what mainstream science wants you to believe.”

It’s important not to patronize or dismiss people who might challenge established perspectives for a wide variety of legitimate reasons, Strong adds. If scientists and scientific institutions do not communicate in an accessible and useful way – on social media for example, “then people will look for other sources of information and evidence”.

This article is reproduced with permission and has been published for the first time April 22, 2026.