Friday Favorites: Is Fiber an Effective Anti-Inflammatory?

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

“Hippocrates, the father of western medicine, believed that all disease begins in the gut.” Of course, he also thought women were hysterical because of their “wandering uterus.” So much for ancient medical wisdom.

But something like constipation can have a “major [negative] impact on physical, mental and social well-being.” Yet it’s “often overlooked in health care.” This may be because poop-talk is taboo, but it can have “a severe influence on…everyday living,” both psychologically and physically. Constipation can hurt, causing “abdominal discomfort and pain, straining, hard stool, infrequent bowel movements, bloating and nausea.”

No wonder “[l]axatives are among the most commonly used drugs. Most are safe when used judiciously [and] intermittently,” but because of the frequency of their use, they end up being one of the most common causes of adverse drug reactions. Perhaps “treatment should [instead] address the underlying problem,” such as lack of dietary fiber. You probably don’t need a meta-analysis to demonstrate that “dietary fiber can obviously increase stool frequency.”

“Populations in most Western countries must be considered by world standards to be almost universally constipated.” Here, it’s an epidemic among the elderly, but it’s simply not a problem among those centering their diets around fiber-rich foods. Where is fiber found? This patient summary in the AMA’s journal sums it up with an illustration: whole unrefined plant foods. Now for those of us smug in our intake of fruits and vegetables, we need to realize that “fruits and leafy vegetables are the poorest whole food sources of fiber.” Why? Because they’re 90 percent water. Root vegetables have more, but the fiber superstars are legumes, which means beans, split peas, chickpeas, and lentils, as well as whole grains. And gram for gram, fruit fiber doesn’t seem to have the same effect. It may take 25 grams of fruit fiber to double stool output, something just 10 grams of whole grain fiber or vegetable fiber can do.

And that’s not all fiber can do. If you eat some whole grain barley for supper, by the next morning your good gut bacteria are having it for breakfast, releasing butyrate into our bloodstream—a compound that seems to exert broad anti-inflammatory activities, which could help explain why significant decreases in the prevalence of inflammation are associated with increasing dietary fiber intakes. Check it out. And the highest group here was just getting the minimum recommended daily intake of fiber. So, what, if you have knee pain or something, you should eat more fiber-rich foods? We didn’t know…until now. “Dietary Fiber Intake in Relation to Knee Pain Trajectory.” Thousands of patients were followed and…”a high intake of dietary fiber,” which is to say just the minimum recommended intake, was “associated with a lower risk of developing moderate or severe knee pain over time.” And two Framingham studies found that higher fiber intake was related to a lower risk of having symptomatic osteoarthritis in the first place.

But wait; don’t a variety of diseases have an inflammatory component? How about fiber consumption and all-cause, cardiovascular, and cancer mortality? They found that, compared with those who consumed least fiber, those who consumed the most had 23 percent less cardiovascular disease mortality, 17 percent lower risk of dying from cancer, and 23 percent lower mortality from all causes put together. “Unfortunately, most persons in the United States consume less than half the recommended intake of dietary fiber daily.”

These researchers suggest all sorts of potential mechanisms for which fiber could be life-saving, from improving cholesterol, immune function, and blood sugar control, but there also may be more of a direct cause. If you ask people to bear down as if they’re straining on stool, you can get a rapid increase in intracranial pressure, pressure inside your skull, and indeed, if you look at trigger factors for the rupture of intracranial aneurysms, if you ask hundreds of people who had strokes—bleeds within their brains—one of the biggest trigger factors noted was straining for defecation, multiplying risk seven-fold.

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Motion graphics by Avocado Video