The questionable benefits of exchanging saturated fat with polyunsaturated fat.

From the Magle Stora Kyrkogata 9, Lund, Sweden (U.R.); Saint Luke’s Mid America Heart Institute, Kansas City, MO (J.J.D.); Faculty of Science and Technology, Institute of Clinical Exercise and Health Science, University of the West of Scotland, Hamilton, Lanarkshire, United Kingdom (Z.H.); Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana (F.A.K.); Institute for Consumer Science and Human F or many years we have been told that to prevent cardiovascular disease (CVD), we must lower our intake of saturated fatty acids (SFAs) and instead eat more carbohydrates and polyunsaturated fatty acids (PUFAs). Backed up by the National Cholesterol Education Program, the National Institutes of Health, and the American Heart Association, the medical profession has promoted this idea eagerly, although the number of contradictory scientific reports is almost endless. There is in fact much evidence that doing the opposite is more relevant. Life, Kinjo Gakuin University, Moriyamaku, Nagoya, Japan (H.O.); and German University for Prevention and Health Care Management, Saarbrücken, Germany (N.W.). The Contradictions The main argument for using this diet has been that it lowers the concentration of cholesterol in the blood and thus prevents CVD. This idea was proposed for the first time by Keys, and as support, he presented data from 16 cohorts in 7 countries in an article that has been used as an argument till today. However, although there was a weak association between the intake of SFAs and heart mortality when all cohorts were analyzed together, there were substantial differences within each country in spite of similar intakes of SFAs. Most contradictory was the observation that coronary heart disease (CHD) mortality on the Greek island Corfu was 16 to 17 times higher than that on Crete, although the intake of SFAs was the same on both the islands. Furthermore, in a recent analysis of the data from this study, the authors found that processed foods, primarily carbohydrates, were classified as saturated fats. The UK government and the National Institute of Clinical Excellence have also inappropriately listed biscuits, cakes, pastries, and savory snacks as saturated fats. The diet-heart recommendations of the American Heart Association, published in 1982 and based mainly on Keys’ hypothesis, were already questioned a year later, and since