Clinical Research On Diverticulitis & Low-fiber Diets

The low-fiber diets typical of industrialized nations may contribute to diverticulitis, or the inflammation of herniated pockets in your intestinal lining. In 1971 Drs. N.S. Painter and D.P. Burkitt linked the low-fiber diet common in Western cultures with an increase in the prevalence of diverticular disease, starting in the early 20th century. Although this theory still predominates in medical circles, clinical research has not verified the connection between a low-fiber diet and an increased risk of diverticular disease.

Early Research

In an article published in the May 1971 issue of the "British Medical Journal," Painter and Burkitt propose that diverticulosis, or the presence of weakened areas in the intestinal lining called diverticula, is a deficiency disorder caused by the increased consumption of refined carbohydrates in industrialized countries. The authors noted that since the turn of the 20th century, the incidence of diverticular disease increased dramatically in the United Kingdom, the United States, Australia and France. The authors link this phenomenon to a reduction in fiber in the average diet and an increase in the consumption of refined flour and sugar beginning around 1880. By comparison, diverticular disease in Africa and Asia, where the fiber content in the predominant diet remained high, occurred infrequently as of 1971.

Fiber and Diverticulosis

Clinical research since 1971 has continued to support Painter and Burkitt's theory that a low-fiber diet contributes to diverticular disease, J.R. Korzenik notes in an article published in the November-December 2008 issue of the "Journal of Clinical Gastroenterology." The rough, indigestible material in vegetables, fruits and whole grains adds bulk to stools, easing their transit through the digestive tract. When you replace high-fiber foods with breads, cereals or desserts that are high in refined flour and sugar, digestive wastes become hard and difficult to pass. Straining during constipation exerts pressure on the colon, the segment of the large intestine where diverticula are most likely to form. When diverticula become inflamed, diverticular disease progresses to diverticulitis, a more serious condition that may result in infection, internal bleeding or intestinal perforation. Korzenik calls for new research to advance the understanding of how diverticulosis progresses to diverticulitis.

Dietary Recommendations

A diet containing 20 to 35 g of fiber each day may reduce the abdominal pain, bloating or constipation associated with diverticulosis and prevent the condition from progressing to diverticulitis, advises the National Digestive Diseases Information Clearinghouse. Painter and Burkitt noted that in a clinical trial of 70 patients with diverticulosis, more than 80 percent of patients reported decreased pain after adding fiber to their diet in the form of bran. However, during an acute attack of diverticulitis, when symptoms are severe, your health care provider may recommend you follow a liquid diet to allow your colon to rest while you undergo treatment.

Future Directions

In an article published in the March 2011 issue of the "World Journal of Gastroenterology," G.C. Nguyen and co-authors report a recent increase in the number of American men and women under the age of 45 undergoing hospital treatment for diverticulitis. The authors propose that in addition to a low-fiber diet, rising rates of obesity may contribute to the number of younger adults being hospitalized for diverticulitis. More research is needed to explore the roles of diet, lifestyle and genetic predisposition in diverticular disease.