Health and government groups spend millions advertising on websites that promote misinformation, sometimes unintentionally

By Deidre McPhillips, CNN

(CNN) — In 2021, as the Covid-19 pandemic was in full swing, US Surgeon General Dr. Vivek Murthy issued an advisory warning about the spread of health misinformation.

“Health misinformation is a serious threat to public health. It can cause confusion, sow mistrust, harm people’s health, and undermine public health efforts,” Murthy wrote. “Limiting the spread of health misinformation is a moral and civic imperative that will require a whole-of-society effort.”

That year, and for years since, health and government organizations have spent millions of dollars on advertising that appeared on websites that regularly promote health misinformation — financially supporting this growing health threat, sometimes inadvertently.

In a new study, researchers at Yale University found that health and government organizations accounted for more than 10% of the advertising payments received by websites that promote health misinformation: a total of $35.7 million spent on advertising on 11 sites between 2021 and 2024.

The Yale researchers worked with NewsGuard to identify that set of websites that promote health misinformation that also had ​data available on advertising expenditures. NewsGuard works with trained journalists to assess the content and practices of websites to determine whether they are reliable sources of information.

Health misinformation is one of the most common reasons websites are rated as unreliable, said ​Matt Skibinski, chief operating officer for NewsGuard. Common topics of health misinformation include false claims about vaccines, promoting remedies that are not supported by science and undermining scientific understanding about the causes of different health issues.

“Some of them are just undermining trust in scientific evidence,” Skibinski said. “Some of them can be directly and immediately harmful.”

According to the new study, nonprescription wellness products were the most common type of health advertising found on websites that promote health information: products like supplements that claim to boost energy, support digestion, manage weight or enhance brain function. These types of organizations spent more than $19 million advertising between 2021 and 2024 on websites that promote health misinformation, nearly 6% of total advertising revenue for the set of 11 websites.

But other reputable organizations — including nonprofit health advocacy groups and the US Department of Health and Human Services — also contributed.

“Advertisements from these organizations may enhance trust in misinformation or diminish trust in the government or health organization,” the researchers wrote in their research letter, which was published Wednesday in the journal JAMA Network Open.

The American Heart Association and the Alzheimer’s Association were among the nonprofit organizations identified in the new research as those with advertisements that appeared on websites that promote health misinformation — each spending less than $25,000 a year, on average, between 2021 and 2024.

Both associations expressed clear concern about the spread of health misinformation and a firm commitment to providing credible, science‑based information and resources. Automated advertising programs help the associations efficiently reach target audiences with messages aimed to promote health, but they don’t offer full visibility into every site placement. Even with the use of tools to filter out harmful content, unwanted placements still happen.

“Any advertising placement on sites that publish misleading or inaccurate content is unintentional. When issues are identified, we review them promptly and take steps to strengthen controls and oversight going forward,” the American Heart Association said in a statement.

The Alzheimer’s Association expressed a similar sentiment: “Despite these safeguards, the dynamic nature of digital advertising means ads may occasionally appear alongside content that does not align with our values or standards. When we learn this occurs, we work promptly with our media partners to review placements and take corrective action as appropriate.”

HHS said in a statement that the agency is “doing things differently” under Kennedy’s leadership.

“We are prioritizing evidence-based science, responsible stewardship of taxpayer dollars, and restoring credibility and trust with the American people,” the statement said, without providing specific examples.

Although the dollar amounts spent by these more reputable health organizations and government agencies are much smaller, experts say the impact isn’t immediately quantifiable.

“It’s important to continue these conversations about where people access their information. But what we still don’t know is how much it’s really influencing them,” said Dr. Anne Cappola, a professor at the University of Pennsylvania’s Perelman School of Medicine and executive director of the Penn Medical Communication Research Institute. “In the abstract, you certainly don’t want to pair a credible organization with a non-credible website. But I’m also not sure what the impact is.”

When it comes to combatting health misinformation, ​she says, there are two key factors: whether somebody trusts in science and whether they have critical thinking.

Often, these conversations are best tackled on a personal level in a doctor’s office or one-on-one with another trusted professional, she said.

“Can we make these big changes in how websites or how social media communicate things, or does it end up being at more personal levels that you are able to get people to critically think and understand,” ​Cappola said. “Because that website or that social media site, that’s not going to challenge them, to try to get them to understand, and to really think about what they’re saying or what they’re believing. But other people can.”

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