Sincerely, MAB

So it's no state secret that I'm a huge fan of corny jokes. Or that I'm really in to epidemiology and the health care field in general. I stumbled across this joke a while ago, and reading the whole foo-for-ah surrounding the OMG CHICKEN MCNUGGETS MAKES KIDS STUPID articles that are floating around reminded me of it. So here it is in all its glory:

Q: How many epidemiologists does it take to change a light bulb?

A: Four. One to change the light, and three to criticize the methodology.

I love science headlines because they say things like, "Study says chicken mcnuggets makes your children stupid." But in reality, it's more likely that those of lower socio-economic status, who may have lower IQs than those of higher socio-economic status, are more likely eat poorly, and thus, feed their children poorly. I highly doubt there's an etiological reason for chicken mcnuggets to lower cognitive ability (although I may be proven wrong!).

I guess the theory presented by the paper's authors is that insufficient macro-nutrient intake in youth affects cognitive development. I can buy that, to a certain extent, but I think the more likely scenario is that parents who feed their children junk food regularly, are more likely of lower socio-economic status and may not have access to properly nutritious food. Without reading the study, I can't determine whether or not they have controlled for this, of course.

I'll try and find the actual journal article and see if I can get some more clarity on the issue.

UPDATE: So I've had a chance to read the article (linked here) and I have a number of concerns with the methodology and the conclusions drawn. Just look at table 2 to see what I mean. Is a -1.64 change in IQ, at a population level, really that significant?