Ben Goldacre, a British physician and writer, makes a prediction in this week’s BMJ (subscription required for full article access):
“I’d like to make a sage prediction, seeing as it’s early December. One of the joys of watching bad science coverage in the media—as I have done for four years now—is that you start to spot patterns: and this year, just like every Christmas, as regular as mince pies, I can confidently predict a specific rash of stories: they will explain solicitously that chocolate is good for you—”actually”—and red wine is even better.
It’s not much of a prediction, since in the world of public relations, Christmas has started already. “Choxi+” is milk chocolate with “extra antioxidants,” and the newspapers are fawning over it already: “too good to be true,” says the Daily Mirror; “chocolate that is good for you, as well as seductive,” says the DailyTelegraph. The company is said to “recommend” two pieces of its chocolate a day. “Guilt free,” says the Daily Mail: it’s “the chocolate bar that’s healthier’ than 5lb of apples.” Meanwhile, Sainsbury’s is promoting Red Heart wine—with extra antioxidants—as if drinking the stuff was a duty to your grandchildren.
These products represent triumphs of over-extrapolation from observational data, and laboratory hunches. …
The antioxidant story took a bit of a blow, of course, when people started to do placebo controlled randomised trials with antioxidant vitamin supplements, to see what happened: because overall they seem to do nothing, or at worst, reduce life expectancy. And that’s when you might start to think, well now, perhaps people who eat fresh fruit and vegetables are, just like the people who drink red wine in decorous moderation, living healthily in all kinds of ways. Much like the people who buy vitamin pills. Lusty walks around country mansions. Cycling to work. That kind of thing.
Of course there may yet be something valuable in the antioxidant story, although it’s probably not going to be as simple as dishing them out by the spoonful. And of course observational studies aren’t inherently evil or useless: they’re frequently fascinating, as part of a puzzle. These are all interesting theoretical research findings, as we try to puzzle out the roots of cancer and heart disease.
But they make a pretty thin excuse for flogging chocolate and alcohol. And somewhere out there—right now—a researcher is rubbing their hands with glee, poring over a press release, picturing themselves in the Today programme studios, planning some choice quotes for the Daily Telegraph: something racy about mince pies cutting heart disease because of the raisins, perhaps, or red wine helping you run faster. Well, it’s Christmas. Have another.”