Abstract
In rabbits fed cholesterol-free, semipurified diets, an increase in the intake of casein raises serum cholesterol concentrations, whereas an increase in the dietary level of corn oil has a cholesterol-lowering effect. The question addressed in this study was whether the casein-induced hypercholesterolemia could be antagonized by a high intake of corn oil. Young growing rabbits were fed cholesterol-free, semipurified diets, containing either a relatively low (13.0 energy %) or high level of casein (21.6 energy %), to which extra corn oil (21.1 instead of 5.3 energy %) was added at the expense of an isoenergetic amount of corn starch and dextrose. An increase in casein level as only dietary variable elevated serum cholesterol, whereas an increase in corn oil caused a lowering. The addition of casein to the diet with low content of corn oil produced a high degree of hypercholesterolemia. However, the addition of casein to the diet with high content of corn oil only caused a relatively small increase in serum cholesterol. It is concluded that a high intake of corn oil negates the casein-induced hypercholesterolemia in rabbits.