Soluble fiber-found in oats, apples, and nuts- reduces the inflammation associated with obesity-related diseases and strengthens the immune system, a new University of Illinois study suggests.
"Soluble fiber changes the personality of immune cells-they go from being pro-inflammatory, angry cells to anti-inflammatory, healing cells that help us recover faster from infection," said Gregory Freund, a professor in the U of I's College of Medicine and a faculty member in the College of Agriculture, Consumer and Environmental Sciences' Division of Nutritional Sciences.
This happens because soluble fiber causes increased production of an anti-inflammatory protein called interleukin-4, he said.
The study will appear in the May 2010 issue of Brain, Behavior, and Immunity.
In the experiment, laboratory mice consumed low-fat diets that were identical except that they contained either soluble or insoluble fiber. After six weeks on the diet, the animals had distinctly different responses when the scientists induced illness by introducing a substance (lipopolysaccharide) that causes the body to mimic a bacterial infection.
"Two hours after lipopolysaccharide injection, the mice fed soluble fiber were only half as sick as the other group, and they recovered 50 percent sooner. And the differences between the groups continued to be pronounced all the way out to 24 hours," said Christina Sherry, who also worked on the study.
"In only six weeks, these animals had profound, positive changes in their immune systems," she said.