Soluble Fiber in the Diet Boosts Immune Function
Adding soluble fiber to a healthy diet can boost immunity and also lead to a speedier recovery. Soluble fiber found in apples, oats, nuts, flaxseed, barley and dried peas and beans could boost immune function by raising levels of the anti-inflammatory protein interleukin-4.
The study, conducted on mice, compared the effect of insoluble and soluble fiber effect on immunity. The results have also lead researchers from University of Illinois to suspect that the right kind of fiber could even have benefits for reducing the harmful effects of belly fat.
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 says, "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."
Two groups of mice were fed the same low fat diet – one with soluble fiber and one group received insoluble fiber. When a compound that mimics infection, lipopolysaccharide, was injected into the mice, the scientists found big differences in their response – the mice given soluble fiber were half as sick and recovered fifty percent sooner compared to the other group.
Christina Sherry, now a postdoctoral fellow at the University of Michigan who worked on the study says, the increased immune response was noted two hours after the injection of lipopolysaccharide, “And the differences between the groups continued to be pronounced all the way out to 24 hours.”
"Now we'd like to find a way to keep some of the anti-inflammatory, positive effects that develop over time with a high-fat diet while reducing that diet's negative effects, such as high blood glucose and high triglycerides. It's possible that supplementing a high-fat diet with soluble fiber could do that, even delaying the onset of diabetes," says Freund.
Reading food labels is not always easy when it comes to sorting out what kind of fiber you're getting. "Not all fiber is created equal, although you wouldn't know that by reading nutrition labels," says Sherry, who adds that explicit nutritional information should be included on packaging labels.
Insoluble fiber can aid digestive health, but failed to do anything for immune function. The FDA recommends 28 to 35 grams of total fiber daily, with a focus on wheat, whole grain brain, and green leafy vegetables.
Incorporating soluble fiber into your daily diet could help fight infection and lead to a speedier recovery from colds and flu - just by eating foods like apples, nuts, carrots, strawberries and citrus fruits.