Apples, nuts, oats boost immune system

URBANA, Ill., March 4 (UPI) -- An apple a day may indeed keep the doctor away by reducing inflammation associated with obesity-related diseases, U.S. researchers say.

Gregory Freund, a professor at the University of Illinois, says soluble fiber found in oats, apples and nuts reduces inflammation associated with obesity-related diseases and strengthens the immune system.

"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," Freund said in a statement.

Soluble fiber causes increased production of the anti-inflammatory protein interleukin-4, Freund said.

In the study, 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," Freund said.

The study is published online ahead of print in the May issue of Brain, Behavior and Immunity.