Oatmeal and oat bran, it seems, do lower total cholesterol after all.

At least that's the conclusion of researchers at Northwestern University Medical School, who say that enormous quantities of the fiber are not required to produce a measurable benefit.

The study, published in the February issue of the American Journal of Public Health, of 80 men and women with higher than normal levels of total cholesterol and of the harmful low-density lipoproteins --

LDL -- demonstrated that the addition of two ounces of instant oatmeal a day was enough to help lower cholesteral levels in general and LDL levels in particular. The participants were volunteers recruited from a Chicago bank.

Half of the participants were given one-ounce packets of oatmeal and instructed to eat two servings per day, not necessarily at the same time.

After eight weeks, the oat group demonstrated reduced cholesterol, while the control group did not.

The authors of the study, led by community health professor Linda Van Horn, say that the approach "is practical, feasible, nutritious and efficacious in lowering blood cholesterol."

In an accompanying editorial, Charles G. Humble, an epidemiologist at the University of North Carolina, said that since 1963 a series of studies has suggested cholesterol-lowering benefits from oatmeal and oat bran.

Only one, published last year in the New England Journal of Medicine, suggested that other factors in the diets of the study subjects accounted for lowered cholesterol levels.