Sunday, May 11, 2014

Unsettling Science: Saturated Fat and Heart Disease, and Where We've Gone Wrong

The Wall Street Journal has published a review of a book sure to raise a controversy, or more accurately revive a standard one, this time taking on the nutrition industry, an area just as corrupted and exploited by government grants, bastioned academics, and commercial interests as any other pop science.

Nina Teicholz has been a reporter for National Public Radio and authored articles for Men's Health, Gourmet, the Economist, and the New York Times, et al., studied biology at Yale and Stanford and earned a masters degree as an Oxonian (to revive a slightly arcane term).  Her new book, The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet will be published by Simon & Shuster next Tuesday the 12th, and it presents the argument that the accepted wisdom about a diet high in fat leading to heart disease is based on a highly flawed study.  Citing a study from a recent issue of Annals of Internal Medicine that questions the link between saturated fat and heart disease, she states:
The new study's conclusion shouldn't surprise anyone familiar with modern nutritional science, however.  The fact is, there has never been solid evidence for the idea that these fats cause disease.  We only believe this to be the case because nutrition policy has been derailed over the past half-century by a mixture of personal ambition, bad science, politics and bias.

Our distrust of saturated fat can be traced back to the 1950s, to a man named Ancel Benjamin Keys, a scientist at the University of Minnesota.  Dr Keys was formidably persuasive and, through sheer force of will, rose to the top of the nutrition world – even gracing the cover of Time magazine – for relentlessly championing the idea that saturated fats raise cholesterol and, as a result, cause heart attacks.
Dr Keys published a study that quickly became the settled science, an examination of some 13,000 men in the US, Japan, and Europe, that purportedly proved that heart disease was the result of poor nutrition.
Critics have pointed out that Dr Keys violated several basic scientific norms in his study.  For one, he didn't choose countries randomly but instead selected only those likely to prove his beliefs, including Yugoslavia, Finland and Italy.  Excluded were France, land of the famously healthy omelet eater, as well as other countries where people consumed a lot of fat yet didn't suffer from high rates of heart disease, such as Switzerland, Sweden and West Germany.  The study's star subjects – upon whom much of our current understanding of the Mediterranean diet is based – were peasants from Crete, islanders who tilled their fields well into old age and who appeared to eat very little meat or cheese.

As it turns out, Dr Keys visited Crete during an unrepresentative period of extreme hardship after World War II.  Furthermore, he made the mistake of measuring the islanders' diet partly during Lent, when they were forgoing meat and cheese.  Dr Keys therefore undercounted their consumption of saturated fat.  Also, due to problems with the surveys, he ended up relying on data from just a few dozen men – far from the representative sample of 655 that he had initially selected.  These flaws weren't revealed until much later, in a 2002 paper by scientists investigating the work on Crete – but by then, the misimpression left by his erroneous data had become international dogma.
The rest of the article explains more of the flaws and shoddy methodology, the results on our health, and how entrenched is the industry, pushing carbohydrates instead.  It is a very interesting read, and she concludes:
Our half-century effort to cut back on the consumption of meat, eggs and whole-fat dairy has a tragic quality.  More than a billion dollars have been spent trying to prove Ancel Keys' hypothesis, but evidence of its benefits has never been produced.  It is time to put the saturated-fat hypothesis to bed and to move on to test other possible culprits for our nation's health woes.
This is just another stanza in the dirge that represents the hijacking of science, and its reliance on the fallacy of ipse dixit – an appeal to authority – that is already found in global cooling, global warming, climate change disruption, as well as the discovery that increased levels of iron are not, in fact, a guard against heart disease (au contraire), or the embarrassment of the public discovery that the previous dogma of the food pyramid and its claim of a healthy diet happened to be quite similar to the USDA's recommendation for a diet to fatten livestock, to name but a few examples.

I don't recommend the article as an argument that we should eat more fat – I don't believe that it is actually saying that so much as it is that certain types of fat are more beneficial, but it is an excellent revelation of how pop 'settled' science is sold to a gullible audience.  (It is a neat temptation though, much as I love my steak and bacon, and this can go along with the discovery that the best source of lycopenes, so important to men's health, can be found in cooked tomatoes, leading immediately in my mind to the pizza diet.)

Cicero is credited, among others in history, with the observation that nothing is so absurd that it has not been said by some philosopher.  We should extend that observation to the various battalions of charlatans in lab coats.

Update:  Walter Willett of Harvard weighs in on the subject with a lengthy yet easily informative discussion on NPR, expanding on the topic.  Such as:
[T]he food guide pyramid that was developed in 1991 really is based on the idea that all fat is bad.  Therefore [if] fat is bad, and you have to eat something, carbohydrate must be wonderful.  So the base of the pyramid is really emphasizing large amounts of starch in the diet.  We're told we can eat up to 11 servings a day, and if that wasn't enough starch, the pyramid puts potatoes along with the vegetables, so you can have up to 13 servings a day.  That's a huge amount of starch….

Fat's up at the top of the pyramid, and where it says explicitly "fats and oils, use sparingly."  It doesn't make any distinction about the type of fat, and it tells us to eat basically as little as possible….

[T]his pyramid is really not compatible with good scientific evidence, and it was really out of date from the day it was printed in 1991, because we knew, and we've known for 30 or 40 years that the type of fat is very important.  That was totally neglected.


  1. I'm an old Atkins dieter, since 2002, actually, so I long ago learned to appreciate fat and stay away from bread. Even my grandmother knew that eating bread and potatoes would make you fat. That and sugar, of course. The real killer pyramid which was out for a few years was the one that recommended eating sugar before fat. I feel sorry for people who trust the federal government.

    1. I'm cutting back on potatoes, already down on bread (easier since my wife was diagnosed with Celiac). All this back-and-forth brings to mind Newton's Second Law of Expert Testimony: "For every expert, there is an equal and opposite expert."


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