title: A high-fiber diet does not protect against asymptomatic diverticulosis.
abstract: OBJECTIVE
  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 cross-sectional 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 bowel 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.
authors: Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7555, USA.
authors: Anne F
authors: AF
authors: Peery
authors: Patrick R
authors: PR
authors: Barrett
authors: Doyun
authors: D
authors: Park
authors: Albert J
authors: AJ
authors: Rogers
authors: Joseph A
authors: JA
authors: Galanko
authors: Christopher F
authors: CF
authors: Martin
authors: Robert S
authors: RS
authors: Sandler
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D003248:Constipation / Q000150:complications; D003430:Cross-Sectional Studies; D004032:Diet; D004034:Diet Surveys; D059305:Diet, High-Fat; D004043:Dietary Fiber; D043963:Diverticulosis, Colonic / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D016012:Poisson Distribution; D015995:Prevalence; D012307:Risk Factors; D057185:Sedentary Behavior; D011795:Surveys and Questionnaires