Can You Really Trust the Health News You Read Online?

Are science-backed headlines bad for your health? A new study published in The BMJ shows that you can’t always trust what conclusions news stories draw about the latest research.

Researchers wanted to look at how often press coverage misrepresents scientific studies. So they analyzed 462 press releases from 20 leading research universities in the UK, comparing their claims to those found in the peer-reviewed paper on which they were based. After analyzing the news stories those press releases generated, the researchers traced whether the papers’ claims got inflated in translation to mainstream media. They focused on three main types of exaggeration: flawed health recommendations to change their behavior based on the “findings”; a causal association when a merely correlational one existed; and the application of animal data to the health of humans.

A full 40% of press releases contained exaggerated advice, 33% drew causative conclusions from mere correlation, and 36% drew human conclusions from animal data.

Press coverage largely followed suit, based on those flawed releases. While “there actually wasn’t that much exaggeration being invented fresh in the news,” the rates of exaggeration were much lower when press releases stayed true to the research, said the study’s co-author Petroc Sumner, PhD, a professor of neuroscience at Cardiff University in the UK.

“If you ask the scientists who’s to blame when things go wrong, 100% of them say journalists,” says Sumner. “But at least 30% of them admitted that their own press releases had exaggeration, even when they’d been heavily involved in writing them themselves.”

Why would an institution issue an inflated press release? “Universities are now all in competition with each other,” Sumner explains. “Academics have now felt this pressure, and we’re all being encouraged to come out of our ivory towers and make what we do known in the real world.”

Time-crunched journalists also feel pressure to publish, and often do so without fully investigating a university’s claims, he says. Overreaching press releases breed over-promising headlines—bad news for the majority of the population that still get most of their health and science information from media sources, Sumner says.

“That’s an awful lot of people, many, many millions of people, making lifestyle decisions based on information about health or health-related science that they’ve read in papers or heard on the news…much more so than based on actual government-driven or medically-driven public health campaigns,” he says, adding that it’s common for people to ask for certain drugs or stop taking medication based on headlines they’ve heard or read. “The cumulative effect of so much potential exaggeration and misinformation could be very large.”

News outlets didn’t differ much from one another in terms of which ones exaggerated more. Instead, press releases seemed to be the most significant factor. “In a sense, that’s actually good news,” Sumner says. “As academics, we have the power to change universities. We don’t have the power to change the pressures in newsrooms.”