Serum Cholesterol in Man and the Unsaponifiable Fraction of Corn Oil in the Diet.

Abstract

Comparison of corn oil with 4 other oils of the linoleic-oleic acid type in controlled switchback dietary experiments in man indicated that corn oil consistently produced serum cholesterol values lower than those predicted on the basis of fatty acid composition by the multiple regression equation previously described. The mean discrepancy in 4 sets of comparisons with 13 to 25 men each and 100 g of each oil in the daily diet was 9 mg per 100 ml. Addition of unsaponifiable matter equivalent to that in 55 g of corn oil to the daily diet containing 140 g of fat of which 100 g was a mixture of safflower and cottonseed oils, produced a mean decrease of 3.2 mg of cholesterol per 100 ml of serum. This effect although statistically nonsignificant matches the discrepancy observed in the earlier comparisons. It is concluded that the unsaponifiable matter of 100 g of corn oil lowers serum cholesterol by something between 6 and 12 mg/100 ml. This effect cannot possibly account for the entire decrease of serum cholesterol observed when corn oil is substituted for saturated fat or for carbohydrate in the diet.