From Gwyneth Paltrow's sun-exposure advice to Jenny McCarthy's anti-vaccine views, the public devours medical advice from celebrities with reckless abandon.
But now new research sheds light on why people fall victim to bogus medical advice from celebrities, suggesting we are hard-wired to listen to it.
Researchers from McMaster University and the Harvard School of Public Health looked at how celebrities gain credibility as medical advisers and why the public can fall under their influence when making important health decisions.
"It makes sense to follow a model's advice on fashion or an actor's advice on presentation, or a former president’s advice on foreign policy," Steven Hoffman, lead researcher and medical professor at McMaster University, tells CBC. "But it doesn’t make sense to follow Jenny McCarthy’s advice on vaccines."
His study, published in the British Medical Journal, analyzed economic, marketing, psychology and sociology studies from 1806 to the present day.
After carefully examining all the data, Hoffman and his team conclude there are a few reasons the public falls prey to such pseudo-science advice.
The "halo effect": People generally trust celebrities well beyond their level of expertise, to the point of ignoring conflicting information.
The "self-esteem motive": We want to look and feel the way they feel, so we purchase products they endorse.
"Herding": The dangerous belief that if everyone is doing it, it must be safe.
The "cool factor": We want "social capital" among our peers, so we follow celebrities blindly.
While celebrity health advice can sometimes be helpful, it is often not, says Hoffman.
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He notes that in the month after Katie Couric broadcast undergoing a colonoscopy, colorectal screening in the United States increased by 21 per cent.
"People need to always be thinking about what evidence underpins whatever health claim we hear," he says. "Is it supported by studies on humans or animals? Was it a trial or based on one person’s experience?"
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