VARIANCE AND DISSENT Presentation The Questionable Role of Saturated and Polyunsaturated Fatty Acids in Cardiovascular Disease

ABSTRACT. A fat diet, rich in saturated fatty acids (SFA) and low in polyunsaturated fatty acids (PUFA), is said to be an important cause of atherosclerosis and cardiovascular diseases (CVD). The evidence for this hypothesis was sought by reviewing studies of the direct link between dietary fats and atherosclerotic vascular disease in human beings. The review included ecological, dynamic population, cross-sectional, cohort, and case-control studies, as well as controlled, randomized trials of the effect of fat reduction alone. The positive ecological correlations between national intakes of total fat (TF) and SFA and cardiovascular mortality found in earlier studies were absent or negative in the larger, more recent studies. Secular trends of national fat consumption and mortality from coronary heart disease (CHD) in 18–35 countries (four studies) during different time periods diverged from each other as often as they coincided. In cross-sectional studies of CHD and atherosclerosis, one group of studies (Bantu people vs. Caucasians) were supportive; six groups of studies (West Indians vs. Americans, Japanese, and Japanese migrants vs. Americans, Yemenite Jews vs. Yemenite migrants; Seminole and Pima Indi-ans vs. Americans, Seven Countries) gave partly supportive, partly contradictive results; in seven groups of studies (Navajo Indians vs. Americans; pure vegetarians vs. lacto-ovo-vegetarians and non-vegetarians, Masai people vs. Americans, Asiatic Indians vs. non-Indians, north vs. south Indians, Indian migrants vs. British resi-dents, Geographic Study of Atherosclerosis) the findings were contradictory. Among 21 cohort studies of CH