Most people with moderately high cholesterol levels would do just as well eating 1 1/2 cups of oat bran every day rather than taking expensive drugs, researchers say.

A cost-effectiveness analysis in Friday's Journal of the American Medical Association indicates that a physician-supervised oat bran diet which is high in soluble fiber would be just as effective in preventing heart attacks as two commonly prescribed drugs, and less than a third of the cost.Dr. Bruce Kinosian, an assistant professor of medicine at the University of Maryland in Baltimore, acknowledged that some people may not want to eat that much oat bran, but "that's just for demonstration purposes."

"There are many foods that are rich in soluble fiber: beans, legumes, the pectin in apples, oranges, grapefruits," he said. "The important thing is to have a diet high in overall soluble fiber and to monitor its effectiveness."

Cholesterol is a fatty, waxy substance in the blood that can build up on artery walls, causing the artery-narrowing disease called atherosclerosis. Atherosclerotic arteries are a major cause of heart attacks and stroke.

Cholesterol is measured in milligrams per 100 milliliters of blood. Federal guidelines issued in October established 240 as high cholesterol, 200-239 as borderline and below 200 as acceptable. A cholesterol reading of 180 is considered ideal, but 80 percent of adult American men are above that level.

Some people can reduce their blood cholesterol levels by cutting down on fats and cholesterol in their diet, but many of these people still become candidates for drug treatment. Kinosian and his colleagues wondered whether further dietary intervention, with the addition of soluble fiber, could prove an effective and inexpensive alternative to drugs.

The scientists noted the cost-effectiveness of incorporating 1 1/2 cups of oat bran into the daily diet vs. treatment with colestipol or cholestyramine resin, two common cholesterol-lowering agents. The bran, like the drugs, binds to bile acids, reducing their availability in the production of cholesterol.

Although previous studies indicated the bran and drugs would produce similar reductions in cholesterol levels, the researchers found the diet therapy, even if supervised by a physician and nutritionist, would cost $248 a year per patient vs. $879 for colestipol and $1,442 for cholestyramine.

The cost of the bran alone was about $40 a year.

Each 1 percent drop in cholesterol levels is associated with a 2 percent drop in heart attack risk. Based on this and calculations about the proportion of men needing treatment, the researchers estimated that widespread dietary intervention in men with cholesterol levels of 260 would cost about $17,800 per year of life saved, compared to $70,900 for colestipol and $117,400 for cholestyramine.

Though certain people with very high cholesterol levels or other risk factors for heart disease may require drug therapy, dietary intervention makes better sense for most people who need to lower their cholesterol, Kinosian concluded.

"If you can do it with diet, why use drugs?" he said in a telephone interview. "There are clearly people who need drugs to lower their cholesterol, but there are other options out there that may be more cost-effective and are not being emphasized.