Why hype in press releases is ineffective – and how to fix it?

Press releases sometimes exaggerate scientific findings and omit study limitations. Scientists are investigating why, and testing ways to make them more accurate.

If you are a regular reader of health news, then you will be no stranger to attention-grabbing headlines. Do expressions like ‘historic medical breakthrough’, ‘landmark discovery’, ‘greatest medical achievement ever’ sound familiar? All of them were used in the press releases about a 2017 journal article that investigated whether niacin supplementation would impact the formation of birth defects in mice. The headline of the journal article itself was cryptic to the non-expert but factually correct. So where in the news pipeline was the spin introduced?

That question sparked the interest of three researchers at the Melbourne School of Population and Global Health. They conducted an investigation into the original study, its press release and a sample of 60 news articles selected from the media coverage that followed. The team, led by Georgia Dempster, found that while the journal article contained no sensationalist elements such as buzzwords or framing, the press release very much did. And in many cases, so did the news stories.

It sounds like a game of Chinese whispers, but with much higher stakes. A significant number of press releases and the health articles that are based on them falsely imply that novel treatments can be applied to humans when in reality they were tested on rodents under controlled laboratory circumstances. In the case of the niacin study, some of the news coverage not only ‘forgot’ to mention that it was only conducted on mice but also issued recommendations that pregnant women should take niacin supplements. In reality, Dempster’s team notes, consuming too much niacin can harm mothers-to-be and their unborn babies.

The exaggeration around the niacin study is no isolated case. In a large 2014 study, researchers led by psychologist Petroc Sumner analysed the contents of 462 press releases. They found that 40 % of them contained more direct advice than the original publication. When the press releases were hyped, the news stories were 20 times more likely to be hyped, too. Almost half of the news articles that related to animal studies implied that the studies were applicable to humans. Sumner found a surprising fact: contrary to popular opinion, exaggerated press releases were picked up by the media just as often as their accurate cousins.

Sumner has conducted more research into hype in press releases. In 2019, he participated in a study that tested how interventions in press releases influence their media uptake. Press officers sent their press releases to the scientists behind the studies, who then checked them for evidence strength, causal-correlational mix-ups and missing limitations. They then returned corrected versions to the press officers.

Petroc Sumner profilePetroc Sumner, psychologist and co-director of the InSciOut science in the media project: “One in five journalists would pick up on a limitation if it was present in the press release. Before that, nobody did”. – Read Petroc Sumner’s full interview


Elements that are frequently omitted in press releases include the limitations of the scientific study, funding sources and conflicts of interest, according to a study led by public health researcher Maike Winters from the Karolinska Institute. Positive framing could explain this phenomenon. The team defined 12 essential measures that define high-quality press releases, among which are the main aim, the study design, the sample size and the main findings.

Cultural differences emerged from Winters’ study too, as she analysed more than 500 press releases across five countries. Not only was the number of press releases per scientific publication higher in the United States (US) and the United Kingdom (UK) than in Germany, the Netherlands and Sweden, but the number of news stories produced per press release was also significantly higher in these two countries.

Maike Winters profileMaike Winters from the Karolinska Institute: “Funding structures make a difference….In the US, where research funding is less secure than in Europe, more promotion is needed to attract funders.”
Read Maike Winters’ full interview


Winters proposes a set of scientific measures that press officers could use as a checklist before publishing press releases. For example, is the correct relationship between exposure and outcome mentioned in the title? Does the title contain buzzwords such as ‘ground-breaking’ or ‘first’? Both Winters and Sumner agree that it is especially important for headlines to give accurate information, because many readers do not read the full text. And even when they do, their first impression might leave a lasting effect on how they interpret the remaining text.

Hyped science is a complex phenomenon that can be traced back to the work of scientists, press officers and journalists. It would be too easy to heap all the blame on press officers alone. Both scientists and press officers have an intrinsic interest in promoting their institutions’ scientific findings, which is why they share responsibility for the accuracy of their press releases. But how journalists handle press releases and how much of them they take at face value needs scrutiny as well.

In fact, some of the exaggerations can be stopped right at the interface between press release and news article. Together with Petroc Sumner, science communication scholar Ionica Smeets conducted a study into how journalists handle expert quotes from press releases. They found that only around 7% of British and Dutch news articles contained independent expert quotes. The chances of an article giving hyped-up scientific findings were two-and-a-half times higher when the article’s authors did not gather independent expert quotes.

Ionica Smeets profileIonica Smeets, professor of science communication at Leiden University, the Netherlands: “One way to mitigate this issue is science media centres.They collect independent comments and quotes on new studies which put the studies’ findings and methods into context” (picture © Ype Driessen). – Read Ionica Smeets’ full interview

Smeets adds that, while Germany and the UK have successfully set up science media centres, more research is needed to measure the actual effects they could have on mitigating exaggerations originating in press releases.

It is likely that an independent assessment of the 2017 study on niacin and birth defects would have cast a more realistic light on the press release’s bold claims. The fact that the findings are based on a study conducted on mice is buried under a heap of buzzwords like ‘blockbuster’, ‘world-first’, ‘breakthrough’ and ‘landmark study’ which serve no other purpose than to promote the institute. In reality, most science is less glitzy, so journalists and readers might be best advised to take overstated claims with a pinch of salt.

Related content:
A scientist’s opinion: interview with Petroc Sumner on hype in press releases
A scientist’s opinion: interview with Ionica Smeets on hype in press releases
A scientist’s opinion: interview with Maike Winters on hype in press releases