WHO Scientific Update on health consequences of trans fatty acids: introduction

The role of dietary fats and oils in human nutrition is one ofthe most complex and controversial areas of investigationsin nutrition science. The first expert consultation thatfocused on the topic of fats was the Joint FAO/WHO ExpertConsultation on the Role of Dietary Fats and Oils in HumanNutrition held in Rome from 21 to 30 September 1977 (FAO,1978). This consultation synthesized the state of knowledgeof dietary fats and oils in human nutrition, including nutri-tional value and both the positive and negative physiologicaleffects of different types of fats. Then the Joint FAO/WHOExpert Consultation on Fats and Oils in Human Nutritionwas held in Rome from 19 to 26 October 1993 to considerthe latest scientific evidence on many crucial and variedroles dietary fats and oils have in human nutrition andexamine the intakes of different types and levels of dietaryfats and oils and their associated health effects (FAO, 1994).The Joint WHO/FAO Expert Consultation on Diet, Nutri-tion and the Prevention of Chronic Disease held at Genevafrom 28 January to 1 February 2002 (WHO, 2003; Nishidaand Shetty, 2004) recognized that the growing epidemic ofchronic disease afflicting both developed and developingcountries was related to dietary and lifestyle changes. Duringthe past decade, rapid expansion in a number of relevantscientific fields and in the amount of population-basedepidemiological evidence has helped to clarify the role ofdiet in preventing and controlling the morbidity andpremature mortality resulting from various noncommunic-able diseases (NCDs). One of the resulting recommendationsaimed at reducing the risk of cardiovascular diseases and inpromoting cardiovascular health was that diets shouldprovide a very low intake of trans fatty acids (TFA), that is,less than 1% of total energy intake. The outcomes andrecommendations of this Expert Consultation then providedthe scientific basis for the WHO Global Strategy on Diet,Physical Activity and Health (DPAS) endorsed by the 57thWorld Health Assembly in May 2004 (WHO, 2004).