Keys and his collaborators in each country measured body weight, blood pressure and cholesterol levels of adult men in each country. Sampling was done in the 1960s and revealed in the 1970s, in an American Heart Association journal.
But when Teicholz looked further into the Seven Countries data, she found glaring errors. Greek islands Crete and Corfu were sampled multiple times, and once during Lent. 60 percent of those on Crete were fasting one of the three times they were sampled. Based on this obviously errant sampling, we’re supposed to follow a Mediterranean diet.
Keys reported the study’s details in a little-known Dutch journal that he had previously been disappointed in, in terms of publicity. But the AHA journal still held the fireworks, allowing Keys to focus on his key takeaways. The paper also makes no mention of other problems with the study, like using multiple methods of evaluating fat in food samples.
Going back 25 years in 1999, the lead Italian researcher re-analyzed data for his country and found a higher correlation with sweets (0.821 – and not including chocolate, ice cream, and soft drinks) than that of animal foods (0.798 – including margarine, in this case). Sugar was only lightly touched upon in Keys’ paper. Yet, this Seven Countries study is considered the final evidence of the theory that saturated fat in animal foods causes heart disease.
But again, this was only a correlation, or an association. It was not a cause-effect study because it wasn’t a clinical trial, instead it was an epidemiological survey.
Meanwhile, reputable studies in North Dakota, Ireland, India, Pennsylvania, Massachusetts, of competing tribes in Africa (one vegetarian and one meat-eater), Eskimos, and even an egg-eating doctor countered some of Keys’ research. But, today, most of those dissenters have died, and the “logical” cholesterol leading to heart disease theory stands firm, according to Teicholz.
Keys and a colleague jumped on an American Heart Association committee in the late 1950s, despite neither being trained in nutrition. That committee advocated dumping saturated fats found in meat, cheese, whole milk, and other dairy products in 1961, and Ancel Keys wound up on the front of Time magazine.
The genius, Keys, was a persuader. The animal fat theory won out over the carbohydrate and sugar theories. Keys would refute, rather than just comment, on opposing papers.
The polyunsaturated puzzle
With the American Heart Association, National Institutes of Health, and USDA all favoring a low-fat diet, it can be hard to imagine the new “food pyramid” or “MyPlate” tools coming out with a positive view of fat. But until 1910 the only fats found in the kitchen came from animals; lard, butter, eggs, meat and dairy products. When vegetable oils leapt on the scene, they advertised the polyunsaturated oils as a huge health benefit for lowering cholesterol. “Take this ad to your doctor,” read one Mazola corn oil advertisement. But none of the other effects of these oils had not been studied, like the later-found existence of trans-fats.
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