62% of dietary advice in UK newspapers has 'insufficient' evidence

[muriel_volestrangler]

Doctors, including Ben Goldacre of the 'Bad Science' column in The Guardian, look at the evidence for dietary claims in newspapers:

When scientific claims are wrong, they're often interestingly wrong. That makes them a good teaching tool to explain how real science works. But there's also a broader worry. People make real-world health-risk behaviour decisions based on information from newspapers, and if that information is routinely misleading, there are real-world consequences.

So how much reporting, overall, is unreliable? To find out, you'd have to take a systematic and unbiased sample – perhaps a whole week's worth of stories – and then check the evidence behind every claim. This would be an enormous job, but a new paper in the journal Public Understanding of Science does exactly that. I'm in a strange position to be writing about it, since the study was my idea, and I'm one of the authors.
...
We went through these to pull out every story with any kind of health claim, about any kind of food or drink, which could be interpreted by a reader as health advice. So "red wine causes breast cancer" was in, but "oranges contain vitamin C" was not.
...
Here's what we found: 111 health claims were made in UK newspapers over one week. The vast majority of these claims were only supported by evidence categorised as "insufficient" (62% under the WCRF system). After that, 10% were "possible", 12% were "probable", and in only 15% was the evidence "convincing". Fewer low quality claims ("insufficient" or "possible") were made in broadsheet newspapers, but there wasn't much in it.

http://www.guardian.co.uk/commentisfree/2011/jun/17/bad-science-health-reporting

The paper abstract:

Introduction: Newspaper reports advocating dietary intake changes may impact on dietary choice and food related health beliefs. The scientific basis and quality of evidence underpinning these reports is uncertain. Objective: To evaluate the scientific quality of newspaper reporting related to dietary advice. Design: Articles offering dietary advice from the top ten selling UK newspapers for a randomly selected week were assessed using two established evidence grading scales: developed by the World Cancer Research Fund (WCRF) and the Scottish Intercollegiate Guidelines Network (SIGN). Results: Of 111 dietary health claims identified, 72% and 68% (assessed by WCRF and SIGN criteria respectively) had levels of evidence lower than the convincing or probable categories that are recommended for dietary health claims. Conclusions: Misreporting of dietary advice by UK newspapers is widespread and may contribute to public misconceptions about food and health.

http://pus.sagepub.com/content/early/2011/04/08/0963662511401782.abstract

[LaurenG]

1. Ugh

Misreporting of dietary advice by UK newspapers is widespread and may contribute to public misconceptions about food and health.

Do we need a warning for the health section of newspapers now? "Reading newspapers for dietary health advice may be dangerous to your health."

[Odin2005]

2. Most pop "health" claims are BS woo or ignorant babble.

[Warpy]

3. I keep telling people to watch those weasel words

like "may," "might," "can," and "possibly." They're dead giveaways to preliminary research that might or might not be duplicated.

The best bet is a varied diet eaten with Pollard's advice in mind: "Eat food, not too much, mostly plants."

[astral]

4. For once I agree with you. n/t