Soluble Fiber Strengthens Immune System
A new study from the University of Illinois has found that soluble fiber that is found in oats, apples, and nuts, reduces the 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," 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.
The experiment, done on laboratory mice, found that mice who consumed soluble fiber did not get as ill as other mice who did not consume soluble fiber. "In only six weeks, these animals had profound, positive changes in their immune systems," she said.
Soluble Fiber and Diet
Freund is now proposing a new question: Could soluble fiber offset some of the negative effects of a high-fat diet, essentially immunizing obese persons against the harmful effects of fat? Researchers and scientists have always known that obesity is linked to inflammatory conditions, such as diabetes and heart disease.
Yet, in a recent study, the U of I scientists demonstrated that fat tissue produces hormones that appear to compensate for this inflammation. "There are significant anti-inflammatory components in fat tissue and, if they were strategically unleashed, they could potentially protect obese people from further inflammatory insults, such as a heart attack or stroke. In obese animals, you can see the body compensating in an effort to protect itself," he said.
"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," he said.
This study is one of the first to provide two valuable lessons, said Sherry. The first, already noted, is that soluble fiber has direct anti-inflammatory effects and builds up the immune system. The second is that the amount of soluble fiber necessary to achieve these health benefits is a reasonable, not a pharmacological, amount.
"Not all fiber is created equal, although you wouldn't know that by reading nutrition labels," said Sherry. "Most manufacturers don't tell you how much of each type of fiber a food contains, and we think it's important that this information be included on a product's packaging."
Good sources of soluble fiber are oat bran, barley, nuts, seeds, lentils, citrus fruits, apples, strawberries, and carrots. "We used a citrus-based pectin in our study," Sherry said.
Insoluble fiber, found in whole wheat and whole-grain products, wheat bran, and green, leafy vegetables, is also valuable for providing bulk and helping food move through the digestive system, but it doesn't provide the boost to the immune system that soluble fiber provides.