Dietary fibre intake and the risk of diverticular disease: a systematic review and meta-analysis of prospective studies

A high intake of dietary fibre has been associated with a reduced risk of diverticular disease in several studies; however, the dose–response relationship between fibre intake and diverticular disease risk has varied, and the available studies have not been summarised in a meta-analysis. We conducted a systematic review and meta-analysis of prospective cohort studies to clarify the association between dietary fibre intake, fibre subtypes, and the risk of diverticular disease.

PubMed and Embase databases were searched up to August 9th 2018. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model and nonlinear associations were modelled using fractional polynomial models.

Five prospective cohort studies with 19,282 cases and 865,829 participants were included in the analysis of dietary fibre and diverticular disease risk. The summary RR was 0.74 (95% CI 0.71–0.78, I² = 0%) per 10 g/day. There was no evidence of a nonlinear association between dietary fibre intake and diverticular disease risk, p_nonlinearity = 0.35, and there was a 23%, 41% and 58% reduction in risk for an intake of 20, 30, and 40 g/day, respectively, compared to 7.5 g/day. There was no evidence of publication bias with Egger’s test, p = 0.58 and the association persisted in subgroup and sensitivity analyses. The summary RR per 10 g/day was 0.74 (95% CI 0.67–0.81, I² = 60%, n = 4) for cereal fibre, 0.56 (95% CI 0.37–0.84, I² = 73%, n = 2) for fruit fibre, and 0.80 (95% CI 0.45–1.44, I² = 87%, n = 2) for vegetable fibre.

These results suggest that a high fibre intake may reduce the risk of diverticular disease and individuals consuming 30 g of fibre per day have a 41% reduction in risk compared to persons with a low fibre intake. Further studies are needed on fibre types and risk of diverticular disease and diverticulitis.