The role of unsaponifiable components in the lipidemic property of olive oil.

Pure olive oil triglycerides (POLO), free from all unsaponifiable matter, were isolated from Virgin Spanish olive oil (COLO) by alumina-charcoal column chromatography. COLO and POLO were used as sources of dietary fat in two animal studies. The responses of serum and liver lipids to the two types of dietary fat were examined. Our results show that animals fed POLO-diet gave somewhat higher serum total and LDL cholesterol levels as compared to those on COLO-diet. The increase in serum cholesterol level is followed by a parallel increase in liver cholesterol content. These results indicate that the hypocholesterolemic effect of olive oil was partly due to the presence of the unsaponifiable matter. Supplement of the POLO-diet separately with a-tocopherol and squalene resulted in serum lipid responses similar to that observed with the COLO-diet. The serum and liver triglyceride levels are not affected by the removal of unsaponifiable components but addition of a--T and squalene to the POLO-diet appeared to lower both the cholesterol and triglyceride levels in the serum but increased only the liver cholesterol content. These results show that the unsaponifiable components modulate the hypocholesterolemic effect of olive oil.