Reduction of plasma and hepatic triacylglycerides with whole milk-containing diets in rats.

Two studies were conducted to determine the effect of diets containing milk on plasma cholesterol, triacylglycerides, apolipoproteins, and lipoprotein composition and hepatic lipid levels in rats. In the first study four groups were fed either a diet containing skim milk (SM) powder or whole milk (WM) powder or one of two control diets with casein as the protein source. The SM diet and one casein diet (SM control) each contained 5% fat by weight as corn oil. The WM diet contained 20% fat by weight, derived from the milk powder, and the second casein diet (WM control) contained 20% fat by weight from corn oil and lard. The SM group had similar plasma and hepatic lipids, as did the SM control group; plasma apolipoprotein AI, AIV and B did not differ between the groups, but the apo E level was lower in the control group. The WM group had lower plasma triacylglycerides and apo B and lower hepatic cholesterol and triacylglycerides than did the WM control group. In the second study the WM diet was fed again, and the two control diets contained casein as the protein source, 20% butter oil (so that the level of dietary fat was comparable to that of the WM diet), and either lactose or sucrose was added. The plasma apo B and triacylglycerides and the hepatic cholesterol and triacylglycerides were significantly lower in the WM group than in the casein/lactose or casein/sucrose groups. The amount of protein, cholesterol and triacylglycerides in the VLDL fraction of the plasma was lower in the WM group than in the casein/lactose or casein/sucrose groups.(ABSTRACT TRUNCATED AT 250 WORDS)