Why we should take online diet pill reviews with a grain of salt
IN TODAY’S digital age, they are relied upon by many people looking to find the best buy.
But internet reviews can be wildly misleading, a study has found, because they are usually written by people who exaggerate how good a product is.
Psychologist Dr Mícheál de Barra looked at more than 1,600 online reviews of health products on website Amazon, then compared them with the scientific results of clinical trials.
He found people buying Benecol products to cut their cholesterol put their drop in the harmful fatty substance at three times the actual amount recorded by scientists.
Weight loss pill Orlistat, prescribed on the NHS but also sold online, was thought by people in online reviews to help them lose twice the weight seen in trials.
Dr de Barra, from the University of Aberdeen, said people filling out online reviews were not generally trying to be misleading. Instead, people tended to share positive outcomes more than negative ones.
He added: ‘Only some people who try a treatment will then go on to tell other people about their experience, however, this subset of people are usually only those who have good outcomes.
‘So you hear a friend of yours had a good result using a treatment of some kind, and you think “well, maybe this works.”
‘Your friend is probably not lying, but the problem is that people with average or poor outcomes don’t tend to share their experiences. This means you get a positively skewed view of the treatment.’
The study, published in the journal Social Science and Medicine, is the first to compare clinical trial data with user-generated online reviews. It casts a new light on why these reviews might not be trustworthy, following scandals over malicious posts on sites such as TripAdvisor designed to damage businesses.
In 2012, novelist RJ Ellory was forced to make a grovelling apology after it emerged he had been posting gushing praise of his own work – and attacking others’ novels – under an assumed name on Amazon.
Dr de Barra, who has an interest in historical and contemporary inaccurate medical beliefs, said of his weight-loss findings: ‘These treatments are not entirely ineffective. However, what we show is that the reputation as described in these reviews is much more positive than the clinical trial data show.’
Reviews are thought to contribute to overuse of treatments, when diet and exercise could help people to lose weight and lower their cholesterol.
Dr de Barra said: ‘This study shows how a demand for ineffective medicines can easily develop when people rely on hearsay and narratives alone. We should be cautious about using reviews like these when deciding about health choices. These narratives have a powerful influence on our own future health behaviour because they provide simple and clear anecdotes, but this study shows that they can be very misleading.’