It’s a hard idea to wrap your brain around. The phrase is constant and appears in virtually every article about diet and nutrition: artery-clogging saturated fat.
Except that it isn’t. Unless you’re a rabbit.
As I’m sure most of you know, rabbits are herbivores. What you may not know, is that the study considered the gold standard for proving that saturated fat causes arterial plaque was done by feeding powdered butter (a very low-quality food containing oxidized cholesterol) to rabbits. When autopsied, the rabbits had goo in their coronary arteries. This is not really a surprise as they are not even remotely adapted to such a diet.
Dr. David Kritchevsky further went on to show that consuming polyunsaturated vegetable oils reduced total cholesterol. As we know now, total cholesterol is a pretty useless number.
This lousy advice was then reinforced by the Seven Countries Study done by Ancel Keys. I mentioned this a couple of posts ago, but here’s something Gary Taubes has to say about it in Good Calories, Bad Calories:
Despite the legendary status of the Seven Countries Study, it was fatally flawed, like its predecessor, the six-country analysis Keys published in 1953 using only national diet and death statistics to support his points. For one thing, Keys chose seven countries he knew in advance would support his hypothesis. Had Keys chosen at random, or, say, chosen France and Switzerland rather than Japan and Finland, he would likely have seen to effect from saturated fat, and there might be no such thing today as the French paradox — a nation that consumes copious saturated fat but has comparatively little heart disease.
Based on the same research, especially the rabbit study, it was decreed that we should switch to margarine and Crisco and give up lard and butter. Lard, butter and coconut oil (that one didn’t get the beat-down until the 80s) are all solid at room temperature. The hydrogenation process that creates trans-fatty acids is done to make unsaturated fats behave like these natural fats. Americans were all given some very bad advice in the form of The Prudent Diet.
“Everybody knows” is rarely the case, but once the propaganda machine (and farm policy money) gets rolling, it’s very hard to stop. We were told to eat something that is, by the consensus of more or less the same people, “even worse” than saturated fat, and this went on for fifty years!
From the Wikipedia entry on trans-fat:
Unlike other dietary fats, trans fats are not essential, and they do not promote good health. The consumption of trans fats increases the risk of coronary heart disease by raising levels of “bad” LDL cholesterol and lowering levels of “good” HDL cholesterol. Health authorities worldwide recommend that consumption of trans fat be reduced to trace amounts. Trans fats from partially hydrogenated oils are more harmful than naturally occurring oils.
Michael Pollan does make some assertions with which I cannot agree, but I really love one of his rules for eating: Don’t eat anything your great-great-grandmother wouldn’t recognize as food. .
Next time you read the words “artery-clogging saturated fat”, remember the rabbits.