The Warning on Saturated Fat: From Defective Experiments to Defective Guidelines

  • Fabian M. Dayrit Department of Chemistry, School of Science and Engineering, Loyola Schools, Ateneo de Manila University, Katipunan Ave., Loyola Heights, Quezon City


Coconut oil has been adversely affected by the current dietary guidelines that advocate a lowering of total fat and the replacement of saturated fat with polyunsaturated fat. This recommendation has its origins in the saturated fat-cholesterol-heart disease hypothesis that Ancel Keys first proposed in 1957. This hypothesis became an official recommendation with the publication of the Dietary Guidelines for Americans in 1980 and has been adopted by many other countries and international agencies. The dietary recommendations also warn against coconut oil. Recently, the American Heart Association re-issued this warning in its 2017 Presidential Advisory. However, a critical review of the experiments that Keys conducted has revealed experimental errors and biases that cast serious doubt on the correctness of his hypothesis and the warnings against coconut oil. Further, the recommendation to decrease saturated fat recommendation effectively means an increase in unsaturated fat in the diet. The actual result has been an increase in omega-6 fats and a high omega-6 to omega-3 fat ratio. This unhealthy ratio has been linked to heart disease, the very disease that the AHA wants to target, as well as cancer and inflammatory diseases. Defective experiments have led to defective guidelines. This first paper in this series of papers will present these errors and biases and address the points raised by the AHA.


Anderson JT, Grande F, Keys A (1961). Hydrogenated Fats in the Diet and Lipids in the Serum of Man. J. Nutr. 75: 388-394.
Anderson JT, Keys A, Grande F (1957). The effects of different food fats on serum cholesterol concentration in man. J Nutr. 62: 421-444.
Broste SK (1981). Lifetable Analysis of the Minnesota Coronary Survey. MS thesis, University of Minnesota.
Brühl L (2014). Fatty acid alterations in oils and fats during heating and frying. Eur. J. Lipid Sci. Technol. 116: 707-715.
[CDC] Center for Disease Control. 2016.
[Codex] Codex Alimentarius 210-1999, amended 2015; Codex Alimentarius 33-1981, amended 2013.
Cohen E, Cragg M, deFonseka J, Hite A, Rosenberg M, Zhou B (2015). Statistical review of US macronutrient consumption data, 1965–2011: Americans have been following dietary guidelines, coincident with the rise in obesity. Nutrition 31: 727–732.
[FAOSTAT] Food and Agriculture Organisation Statistics Data. 2006. World lipid availability, Kg/capita/year, 1961. Food Balance Sheets, Rome: FAO.
Frantz Jr. ID, Dawson EA, Ashman PL, Gatewood LC, Bartsch GE, Kuba K, Elizabeth R. Brewer ER (1989). Arteriosclerosis 9:129-135.
Hilditch TP, Vidyarthi NL (1929). The products of partial hydrogenation of higher monoethylenic esters. Proc. Roy. Soc. A, 122(790): 552-563.
Hu FB, Stampfer MJ, Manson JE, Ascherio A, Colditz GA, Speizer FE, Hennekens CH, C Willett WC (1999). Dietary saturated fats and their food sources in relation to the risk of coronary heart disease in women. Am. J. Clin. Nutr. 70:1001–1008.
Index Mundi (2016). http://
Keys A, Anderson JT, Grande F (1957). Prediction of serum-cholesterol responses of man to changes in fats in the diet. Lancet 959-966.
Keys A, Aravanis C, Blackburn H, Buzina R, Djordjević BS, Dontas AS, Fidanza F, Karvonen MJ, Kimura N, Menotti A, Mohacek I, Nedeljkovic S, Puddu V, Punsar S, Taylor HL, van Buchem FSP (1980). Seven Countries. A Multivariate Analysis of Death and Coronary Heart Disease. Harvard University Press, Cambridge, Massachusetts.
Keys A, Menotti A, Karvonen MJ, Aravanis C, Blackburn H, Buzina R, Djordjevic BS, Dontas AS, Fidanza F, Keys MH, Kromhout D, Nedeljkovic S, Punsar S, Seccareccia F, Toshima H (1986). The diet and 15-year death rate in the Seven Countries Study. Am. J. Epidemiol. 124(6): 903-915.
O’Connor A (2016). A Decades-Old Study, Rediscovered, Challenges Advice on Saturated Fat. New York Times, April 13, 2016.
Pietinen P, Ascherio A, Korhonen P, Hartman AM, Willett WC, Albanes D, Virtamo J (1997). Intake of Fatty Acids and Risk of Coronary Heart Disease in a Cohort of Finnish Men. Am. J. Epidemiol. 145(10): 876-887.
Pitts M, Dorling D, Pattie C (2007). Oil for Food: The Global Story of Edible Lipids. Journal of World-Systems Research, Volume XIII, Number 1, Pages 12-32. ISSN 1076-156X.
Ramsden CE, Zamora D, Leelarthaepin B, Majchrzak-Hong SF, Faurot KR, Suchindran CM, Ringel A, Davis JM, Hibbeln JR (2013). Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. BMJ 2013;346:e8707.
Ramsden CE, Zamora D, Majchrzak-Hong S, R Faurot KR, Broste SK, Frantz RP, Davis JM, Ringel A, Suchindran CM, Hibbeln JR (2016). Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73). BMJ 2016;353:i1246
Sacks FM, Lichtenstein AH, Wu JHY, Appel LJ, Creager MA, Kris-Etherton PM, Miller M, Rimm EB, Rudel LL, Robinson JG, Stone NJ, Van Horn LV (2017). Dietary Fats and Cardiovascular Disease, A Presidential Advisory From the American Heart Association. Circulation 135: e1-e24.
Simopoulos AP (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother 56(8): 365-79.
Simopoulos AP (2008). The Importance of the Omega-6/Omega-3 Fatty Acid Ratio in Cardiovascular Disease and Other Chronic Diseases. Exp Biol Med 233(6): 674-688.
Simopoulos AP (2010). Genetic variants in the metabolism of omega-6 and omega-3 fatty acids: their role in the determination of nutritional requirements and chronic disease risk. Exp Biol Med 235: 785–795.
[USDA] United States Department of Agriculture (2017). United States Department of Agriculture. Food Composition Databases.; (downloaded: May 15, 2017).
[USDHHS] U.S. Department of Health and Human Services. 1980. Vital Statistics of the United States 1976. Volume II- Mortality. Part A. National Center for Health Statistics. Hyattsville, Maryland.
Vijayakumar M, Vasudevan DM, Sundaram KR, Krishnan S, Vaidyanathan K, Nandakumar S, Chandrasekhar R, Mathew N (2016). A randomized study of coconut oil versus sunflower oil on cardiovascular risk factors in patients with stable coronary heart disease. Ind. Heart J. 68: 498-506.
Yamagishi K, Iso H, Yatsuya H, Tanabe N, Date C, Kikuchi S, Yamamoto A, Inaba Y, Tamakoshi A, (JACC Study Group) (2010). Dietary intake of saturated fatty acids and mortality from cardiovascular disease in Japanese: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC) Study. Am. J. Clin. Nutr. 92:759-765.
How to Cite
Dayrit, F. M. (2017). The Warning on Saturated Fat: From Defective Experiments to Defective Guidelines. KIMIKA, 28(2), 42-47.