Megan McArdle reports on a new study about red meat:
The correlations between eating red meat and getting heart disease are suggestive. But the mechanism has always been a bit dim… Scientists have isolated what looks like a plausible mechanism by which red meat damages your heart: the gut bacteria of frequent meat eaters process carnitine, a chemical found in red meat, into something called TMAO.
If you’ve been following along, it sounds like the idea that too much red meat gives you heart disease has always been a type of “calculated knowledge,” where we had some interesting correlations but no “direct knowledge” of the actual mechanism. But it sounds like this new study has found something direct! A chemical with an acronym name! Well, almost:
And TMAO is associated with a higher risk of heart attacks.
Another association…. so we peeled back a layer of calculated knowledge and found another one. Sounds like we still can’t describe the biological process by which red meat causes heart disease. But science seems to be getting closer.
That wasn’t the only news this week involving calculated knowledge and food, though.
Where Are All The Fat People?
Everybody knows the South has the fattest people in the country, right? “According to a new study, this Deep South state [Mississippi] is the fattest in the nation.” (NBC) “According to a new joint report by Trust for America’s Health and the Robert Wood Johnson Foundation…. eight of the 10 fattest states are in the South.” (Time) “Mississippi is the fattest state for 6th straight year… states in the South and the Rust Belt tend to rank highest.” (calorielab) Etc, etc.
But not so fast. Would you believe that this commonly accepted bit of folklore was nothing more than “calculated knowledge”? Would you believe that this calculated knowledge might actually be wrong?
The notion that the South is the fattest comes primarily from a nationwide telephone survey done by the Centers for Disease Control, in which the surveyor asks for height and weight, among other things, Howard said.
That survey, the Behavioral Risk Factor Surveillance System (BRFSS), shows the South as the most obese, with Mississippi and Alabama, the number one and two fattest states respectively.
UAB study compared nine Census Bureau regions and found that East Souh Central was fifth, not first, in percentage of its population obese. But the UAB researchers found that when people were actually weighed, the numbers didn’t add up.
Mississippi was fourth and Alabama was in the middle of the pack, Howard said.
Now they’re saying people in the South aren’t the fattest. They just lie less!
Of course, these new results may have their own inaccuracies, depending on how people were weighed and whether or not the people being weighed constituted a representative sample from every state. But it sounds like this new calculated knowledge is a whole lot closer to direct knowledge than the old calculated knowledge, and thus I suspect it’s quite a bit more reliable.