Adults who eat a large bowl of oat bran cereal every day can reduce their blood cholesterol levels by a moderate amount, an analysis of 10 studies has found.
Cholesterol levels fell an average of 2 percent to 3 percent in the 1,278 adults studied. There were larger drops in people with higher blood cholesterol levels.
The study, being published today in the Journal of the American Medical Association, was conducted by Cynthia M. Ripson and Dr. Joseph M. Keenan of the department of family practice at the University ofMinnesota. It was financed in part by Quaker Oats Co.
The researchers used data collected from published and unpublished studies in their analysis. They discarded nine other studies that did not meet their criteria. Most of the studies had found evidence that oat bran reduced cholesterol levels, but three had not.
"From a public health standpoint, even very small changes can have large effects," Ms. Ripson said. She and Dr. Keenan said that a reduction of 1 percent in blood cholesterol levels among Americans could reduce heart disease mortality by about 2 percent.
The overall analysis showed that oat bran does work, Ms. Ripson said.
"But why is this happening?" she asked. "I would be much more comfortable with the results if we knew that."
Dr. Michael A. Davidson, a cardiologist at the Rush Medical School in Chicago who has done his own oat bran study, said there were more ordinary concerns.
"Oat bran certainly will lower cholesterol," he said. "That's been proven conclusively by this study. I think now we need to look at new ways to incorporate soluble fibers in the diet. It's going to be hard to eat a bowl of oat bran cereal every day for the rest of our lives."
And there is some bad news for people who tried to get their bran in tastier ways. Oat bran muffins, a fad food at the height of the bran craze, will not reduce cholesterol. "There may be a drop because of the oat bran, but there will be a rise from the two egg yolks and the other fats," Ms. Ripson said.