How High Fiber Diets Reduce Diverticulitis Risk

Each year, diverticulitis accounts for over 200,000 hospital admissions in the United States. Diverticulitis is a disease of the gastro-intestinal system in which diverticular pouches become infected or inflamed. The suffix "-itis" means inflamed, whereas the suffix "-osis" means "affected with". 

Diverticulosis, the most common lower bowel disorder, is associated with advancing age, being more often found in the colon of those individuals older than 40 years (compared to younger people.) A lack of water and dietary fiber causes high pressures to be generated in the bowel, which creates bulging pockets (diverticula) that can bleed or fill with pus. Only plant foods contain the fiber that can prevent this disorder.

When these pouches which bulge from the colon wall become infected or inflamed, this resulting diverticulitis may obstruct bowel movements, bleed, or cause severe pain in the abdomen. Other symptoms of diverticulitis include constipation, diarrhea, bloating, fever, nausea, cramping, and rectal bleeding. In severe cases, patients may develop abscesses, fistulas, or perforations of the gut wall.

The human gut, especially the colon, houses thousands of different species of beneficial bacteria and other micro-organisms, such as fungi and protozoa. This gut microbiome performs many essential functions, including activation and strengthening of the immune system, and prevention of the growth of harmful micro-organisms. Dietary fiber is the choice food of these gut microbes. These microbes feast on fiber and produce short chain fatty acids. When these fatty acids are absorbed into the bloodstream, they enhance the immune system and fight inflammation. Regular intake of high-fiber diets of whole plant food helps to maintain a healthy, diverse population of gut microbes that directly inhibit the growth of harmful pathogens capable of infecting a diverticular pouch. Unprocessed plant foods reduce inflammation of the gut, thus reducing the likelihood of developing diverticulitis.

Data from several studies have shown that an increased intake of dietary fiber is associated with a decline in the risk of diverticulitis. The findings of a 2011 study published in the British Medical Journal revealed that the chances of being hospitalized for diverticulitis is 41% lower in individuals who consumed 25 grams or more of fiber per day than in persons who ate 14 grams of fiber per day. In another study, researchers found out that a 15% reduction in the risk of diverticulitis was associated with women who consumed an extra 5 grams of fiber per day.