Green beans may be as helpful in lowering cholesterol as the much-touted oat bran.

A Purdue University researcher says eating dietary fiber such as oat bran can help reduce serum cholesterol, but it is not the whole solution.Individual bile acid - there are five in each human - also play key roles in cholesterol reduction, said John A. Story, a nutritional physiologist with the Purdue Department of Food and Nutrition and associate dean of the School of Consumer and Family Sciences.

Story, who researched cholesterol metabolism for 18 years, presented his findings this week at the American Chemical Society, which attracted 8,000 scientists to Dallas.

"It's difficult to translate into consumer terms, but the findings reinforce what we already know about nutrition - that a balanced diet rather than a cure-all such as oat bran is still the answer," he said Tuesday.

A more dramatic finding, Story said, is that the amount of bile acids being secreted as a result of oat bran consumption was not enough to account for the change in cholesterol levels.

In fact, other sources of dietary fiber such as green beans also reduce cholesterol levels, but they did not increase bile acid secretion.

"We had only been looking at the total bile acid pool," Story said, "But individual bile acids may play a part in how fiber lowers cholesterol. The total is important, but what goes into the total may be important, too."

Story said he is now looking at several factors that may help the public's understanding of how dietary fiber regulates both cholesterol and bile acid metabolism.

In other research, he is examining how consumption of dietary fiber may help reduce colon cancer.

Under a $104,963 grant from the American Institute for Cancer Research, Story is looking at how calcium, as well as dietary fiber, affects how much and what types of bile acids reach the large intestine or colon. Bile acids increase the susceptibility to some carcinogens when the bile acids reach the colon.

Findings from both studies, he said, could form the basis for development of diet recommendations for the general public, of development of therapeutic diets for people at greater risk of heart disease and colon cancer.