If you're at all familiar with Ben Goldacre's Bad Science blog and Guardian column, you'll have some idea of what his talk was about - debunking nutritionists, the multi-billion dollar industry nutritional supplement industry they have built, and the overblown claims about the benefits of various food products.
Title: Food, Fads & Fantasies
Abstract: We are frequently bombarded with very specific claims on food and health by the media, the food supplement pill industry, the "functional foods" industry, and the new unregulated "nutritionists". Diet is undoubtedly one of many important lifestyle risk factors for ill health. But to what extent are these stories based in reality? Frequently they rely on basic - and fascinating - errors in scientific reasoning. They quote studies which do not exist, rely only on laboratory data, or extrapolate from weak observational data to make explicit clinical claims. Sometimes there is evidence to show that the claims are actively wrong, and that the advice or commodities being sold may even be harmful. But more than that, there is a risk that this very prescriptive, overcomplicated dietary advice - which speaks so far in excess of the evidence - can be confusing and disempowering, a distraction from simpler health advice, and possibly even detrimental to public health.
Ben began by noting that whereas during the 1950s and 60s science reporting was dominated by stories about engineering and related fields, it is now predominantly about medicine, and particularly about food.
He then gave a brief history of diet quacks, starting with Sylvester Graham, the Connecticut-born Presbytarian minister who in 1837 opened the first health food store. Graham believed that ketchup and mustard cause insanity, and advocated food grown with "physiological principles" and "virgin soil" unspoilt by manure. Such products were, of course, available for sale in his store.
He then continued with a mention of John Harvey Kellogg, who is best known for inventing the Corn Flakes breakfast cereal, and ran a sanitorium where he used holistic methods of treatment which emphasized importance of nutrition and exercize. Kellogg believed in the powers of yogurt enemas, which he incorporated into his well-being program. He also fiercely opposed masturbation, and applied carbolic acid to the clitoris of his female patients to prevent them from doing so. For males, the "cure" for masturbation was circumcision, performed without an anaesthetic, or the sewing shut of the prepuce (the flap of skin which covers the tip of the penis).
Then, there was mention of Senator Dudley J. LeBlanc, inventor of the dietary supplement Hadacol, who organized a travelling medical show which featured Mickey Rooney, Judy Garland and Groucho and Chico Marx. Partly as a result of this, LeBlanc's product became hugely popular, and he had sold more than $20 million dollars worth by 1950.
Modern diet gurus make much more of an effort to provide "scientific" evidence for their products; this usually involves overextrapolating form observational data, misusing statistics, and so on. On prominent example is the "the internationally acclaimed Holistic Nutritionist" Gillian McKeith, who presents a popular television programme in the UK, and has fake degrees form a non-accredited university.
These days, the mass media plays a large role in publicizing overblown claims about the alleged benefits of food items or their components. For example, the Daily Telegraph recently ran a story with the headline Red wine could help prevent breast cancer; in fact, the reverse is true - drinking red wine or any other form of alcohol. One major difficulty in conducting controlled studies on the effects of diet on health is that it is almost impossible to isolate individual risk factors from other aspects of lifestyle (e.g. smoking, alcohol consumption and exercize). Such reporting, which is often partly, or sometimes completely, rehashed from press releases, undermines the public's understanding of how science is done and how data are collected.
As I was in the middle of writing this post, Ben came over and took seat next to me in the conference centre's media room. I've met Ben before, but only very briefly; today, we chatted about trepanation, lobotomy, and various other things, while we both typed away on our laptops. Ben then went down to the tapas bar to give an informal talk to the people there, and I caught it on webcam. The sound quality isn't great, but it's audible.