The Australian Paradox: less sugar, more obesity
I’ve been debating whether to blog about this study since I received an e-mail about it from the Canadian Sugar Institute last week. In general, information from food marketing agencies is pretty suspect. For example, this press release from “Pistachio Health” that also went out last week about a new study:
[...] Additionally, pistachios – also known as the “Skinny Nut” – are shown to be a “mindful snack” in terms of taking longer to eat and requiring the snacker to slow down and be more conscious of what has been consumed. [...]
Yeah, everybody calls them the “Skinny Nut.” Riiiight. Now I really believe that the information you’re sending me is impartial…
Anyway, I’ve decided to blog about this study — a look at sugar consumption and obesity rates in Australia, the U.S. and the U.K. between 1980 and 2003 — because the information is interesting. It’s by two very well-respected Australian researchers (one of whom, for the record — Jennie Brand-Miller — is a lecturer at the University of Sydney’s medical school, where my wife is studying). It’s in a peer-reviewed journal, Nutrients. And as far as I can tell from the disclosures in the paper, it wasn’t in any way funded by the sugar industry: it was a masters project supervised by the two authors. The only reason the sugar lobby is e-mailing it around is because — as you’ll see — they like the results.
The full text of the study is actually available online, so I’m not going to dissect every detail. But the key result is very simple: unlike in the U.S., where sugar consumption has been climbing, per capita consumption of refined and added sugars actually declined by 16% in Australia between 1980 and 2003. During the same period, rates of obesity tripled. Here’s the sugar data:
Now, population data like this always raises lots of questions. The paper discusses the various ways of estimating sugar consumption, along with their pros and cons, and also breaks down sub-categories like sweetened beverages and so on. Without getting bogged down in all that, I think the important point is — as we should all know by now — putting two graphs side-by-side and saying “Hey, they have the same shape! Graph A must have caused Graph B!” is not good science. The recent debate about Robert Lustig’s “sugar is toxic” crusade has involved a lot of this sort of analysis: added sugar intake has increased in the U.S. and so has obesity, ergo A caused B. But if the trend really is the opposite in Australia (and if anyone can suggest reasons why the data above shouldn’t be trusted, please chime in below!), then those arguments are considerably weakened.