A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis

Abstract

BACKGROUND & AIMS The complications of diverticulosis cause considerable morbidity in the United States; health care expenditures for this disorder are estimated to be $2.5 billion per year. Many physicians and patients believe that a high-fiber diet and frequent bowel movements prevent the development of diverticulosis. Evidence for these associations is poor. We sought to determine whether low-fiber or high-fat diets, diets that include large quantities of red meat, constipation, or physical inactivity increase risk for asymptomatic diverticulosis. METHODS We performed a crosssectional study of 2104 participants, 30–80 years old, who underwent outpatient colonoscopy from 1998 to 2010. Diet and physical activity were assessed in interviews using validated instruments. RESULTS The prevalence of diverticulosis increased with age, as expected. High intake of fiber did not reduce the prevalence of diverticulosis. Instead, the quartile with the highest fiber intake had a greater prevalence of diverticulosis than the lowest (prevalence ratio = 1.30; 95% confidence interval, 1.13–1.50). Risk increased when calculated based on intake of total fiber, fiber from grains, soluble fiber, and insoluble fiber. Constipation was not a risk factor. Compared to individuals with <7 bowel movements per week, individuals with > 15 bower movements per week had a 70% greater risk for diverticulosis (prevalence ratio = 1.70; 95% confidence interval, 1.24–2.34). Neither physical inactivity nor intake of fat or red meat was associated with diverticulosis. CONCLUSIONS A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, prevalence of diverticulosis. Hypotheses regarding risk factors for asymptomatic diverticulosis should be reconsidered.

A cross sectional study of colonic diverticulosis in the London Bangladeshi population

“…More recent population studies have largely drawn inference from incidence of complications. [3][4][5] However, the results we obtained in Caucasians correspond to publications of prevalence from unselected colonoscopic examinations in large cohorts, [19][20][21] as well as several historic barium enema 25,26 and a All Bangladeshi patients under the age of 60 years with recorded colonic diverticulosis had a single caecal diverticulum on colonoscopy. The reduced number of patients aged over 70 years with colonic diverticulosis is explained by the reduced number of colonoscopies performed in patients older than 70 years of age.…”

S2k Guidlines for Diverticular Disease and Diverticulitis: Diagnosis, Classification, and Therapy for the Radiologist

“…In contrast, it was able to be shown that increased consumption of nuts and grains tended to reduce the occurrence of diverticular disease [19]. The consumption of red meat also could not be convincingly proven as an influencing factor for the occurrence of diverticulosis [17]. The regular consumption of alcohol, in particular high-proof alcohol, probably correlates with an increased occurrence of diverticular disease and complications.…”

“…Overall, providing proper scientific proof of a connection between a fiber-rich diet and diverticulosis is extremely difficult. Two case control studies [15,16] and two cross-sectional studies did not find a relevant effect of fiber consumption on the occurrence of diverticulosis [17,18]. The decades-long hypothesis that increased consumption of nuts and grains resulted in an increased rate of complications in diverticular disease due to the nuts becoming trapped in the necks of the diverticula also could not be confirmed.…”

Imaging of Ischemia, Obstruction and Infection in the Abdomen

“…Traditional thinking about etiology was that it occurred in patients lacking in dietary fiber 106 , but studies to confirm this are conflicting 107,108 . Diverticulitis occurs when one or more of these diverticula become obstructed at the neck resulting in stasis, inflammation, infection and perforation.…”