The benefits of fiber are more plentiful than we knew. Fiber is good for the heart, may prevent some cancers and now appears to lower C-reactive protein (CRP), an indicator of inflammation found in the blood. A high CRP level signals general inflammation and could indicate anything from an infection to rheumatoid arthritis to heart disease.

It’s not possible to say that eating more fruits, vegetables and other high-fiber foods would help arthritis specifically, but reducing CRP is another good reason to get more fiber, says Dana E. King, MD, professor of family medicine at the Medical University of South Carolina.

Dr. King led a study in which people who ate a high-fiber diet – between 27 and 28 g per day – saw their CRP levels go down. One group got their fiber from foods; another group took a supplement. CRP levels dropped in both groups, but the effects were more dramatic in thinner people – a surprising finding, because previous research suggested overweight people should benefit more.

“It went down about 40 percent in thinner people, but only 10 percent in people who were overweight,” says Dr. King, but researchers don’t know why – nor do they know exactly how eating more fiber can reduce CRP levels.

But evidence is growing. In another study on the benefits of fiber, men who ate a lot more fruits and vegetables – going from two servings to eight per day – lowered their CRP levels by one-third, according to scientists at Germany’s Federal Research Center for Nutrition. The researchers say the drop was mainly due to eating foods rich in carotenoids – special antioxidants that give carrots, peppers and some fruits their color.