Hypo-atherogenic effect of dietary corn oil exceeds hypo-cholesterolemic effect in swine

Three groups of young swine were fed semi-purified diets enriched in fat and cholesterol for 90 days. In one group 40% of calories were from butter; in another 40% were from corn oil; in a third group 20% were from corn oil. Mean serum cholesterol values were respectively 530, 458 and 400 mg/dl. Amounts of atherosclerosis in the abdominal aortas expressed as mean number of nuclear profiles per cross-section were respectively 1611, 734 and 585; expressed as mean lesion area per cross section 46.7, 21.4 and 19.4 mm2 X 10(2). All differences between the butter group and either of the two corn oil groups were statistically significant. We found that intimal response to the butter containing diet was significantly greater than to the corn oil containing diet for equivalent hypercholesterolemic response. We present detailed statistical validation of the disproportionately larger intimal response to butter containing diet. Furthermore, we suggest that estimates of comparative atherogenic risk of food fats based on response of serum cholesterol may mask important atherogenic differences.