According to foodconsumer.org, the study involving 524 health women and men found that those with the highest intake of dietary fiber had lower levels of C-reactive protein (CRP) in their blood than those who ate the lowest amounts.
CRP, a marker of ongoing inflammation in the body, is regarded as a risk factor for future heart disease although its involvement in the disease or even the accuracy of its risk indication is subject to continuing debate. A low-level inflammation in the body is generally believed to be associated with a low risk of future cardiovascular disease.
In the study, researchers measured the blood protein four times in a year in participants who were also surveyed for their diet, exercise habits and other risk factors.
Researchers found 18 percent of men and women had elevated levels of CRP, above 3 milligrams per liter of blood. The level of CRP increased as the fiber intake increased. Those who consumed the highest amounts of the dietary fiber were 63 percent less likely to have an elevated level of CRP.
For a healthy diet, 20 to 35 grams of dietary fiber per day in the form of fruit, vegetables, beans and whole grains, are generally recommended. But Americans eat about half of the recommended amount of fiber everyday, according to the authors of the study.
The highest amounts of fiber consumed by the study subjects were about 22 grams, indicating that people do not have to eat the perfect amount of fiber to have a beneficial effect.
The study also found that both soluble and insoluble fibers from diets were linked with lower CRP levels. Foods like oatmeal, beans, apples and berries contain high levels of soluble fiber whereas foods like whole grains and many vegetables contain high levels of insoluble fiber. The nutritional functionalities of both fibers are different, but both are important.
Researchers do not know how to explain why high dietary fiber intake is linked with low levels of CRP. But they write in their study paper "a diet high in fiber may play a role in reducing inflammation and, thus, the risk of cardiovascular disease and diabetes."
The current study did not reveal any causal relationship between dietary fiber and lower levels of CRP. A possibility that cannot be excluded is that the association between the two may be a result of chance. The finding does not mean eating isolated fiber supplements helps reduce risk of heart disease.