November 1st 2018, 11:50
Repeat a lie long enough and people start believing it, as Joseph Goebbels, Hitler's propagandist-in-chief, once said. Medicine is full of lies—sorry, assumptions of dubious provenance—that everyone believes must be true but aren't. We believe them because medicine is a science (discuss), and they wouldn't just make this stuff up (oh no?)
Here are a few, and you probably believe some (if not all) of them yourself, but they've all been plucked out of the air by 'expert committees.'
Eat your five-a-day
This exhorts us to eat five servings of fruit and vegetables every day. In truth, we should be eating more than that—but where did the idea of five come from? Apparently, it was conjured up in a meeting of fruit and vegetable companies in California in 1991. Strangely, representatives from McDonald's were also there.
It seemed like a good way to sell more produce, but there wasn't a lot of scientific evidence to support the recommendation. At least McDonald's didn't influence the group to include one Big Mac in the healthy eating guidelines—although Heinz succeeded.