Dietary fibre intake and its role in the oesophageal inflammation–metaplasia–adenocarcinoma sequence

Abstract

Recurrent gastric acid reflux can result in inflammation and mucosal erosions in the squamous epithelium of the oesophagus, a condition known as reflux oesophagitis (RO) (1) . Over time, Barrett's oesophagus (BO) can develop when these cells in the distal oesophagus undergo a permanent metaplastic change to columnar-type epithelium (2) . BO is a premalignant condition for oesophageal adenocarcinoma (OAC) and incidence rates of this cancer have tripled in the UK over recent decades (2,3) . Foods containing dietary fibre may protect against oesophageal cancer (4) ; however, the association with OAC specifically, and the stage at which fibre may exert its effect in the inflammation-metaplasiaadenocarcinoma sequence, remains to be clarified.In an all-Ireland case-control study information was collected from patients with OAC (n 224), long-segment BO (n 220), RO (n 219) and healthy population-based controls (n 256) on lifestyle factors and dietary intake using a 101-item FFQ between March 2002 and July 2005. Multiple logistic regression analysis was applied to examine the association between dietary Englyst fibre intake and disease risk, comparing the highest with the lowest tertiles of intake and also using continuous variables. Regression models adjusted for confounding variables including age, gender, energy intake, smoking, education, occupation, alcohol, medication use and after further adjustment for Helicobacter pylori infection.No significant association was identified between fibre intake and RO risk. Dietary fibre was strongly inversely related to BO risk when examining both the highest v. lowest tertile of intake (OR 0.44 (95 % CI 0.25, 0.80)) and per 10 g/d increment in intake (OR 0.54 (95% CI 0.36, 0.83)). This protective association was slightly strengthened after further adjustment for H. pylori infection. An inverse association was also observed between fibre intake and OAC risk, although a dose-response relationship was not apparent, as the reduced risk peaked in the middle tertile of intake (OR 0.52 (95 % CI 0.29, 0.98)).Fibre does not appear to have a role in the initiation stages of OAC development, as intake was unrelated to RO risk. The present study is the first to demonstrate a strong inverse association between fibre intake and BO risk, suggesting a protective effect of dietary fibre in the intermediate stage of the oesophageal inflammation-metaplasia-adenocarcinoma sequence. Fibre intake was also inversely associated with OAC risk, although the effect appeared to plateau in the middle tertile of intake.

A Review of the Associations between Dietary Fiber Intake and Cancer Prevention or Prognosis

“…In studies of upper gastrointestinal cancer, gastric cancer, esophageal cancer, and small bowel cancer, dietary fiber was considered to be inversely associated with tumor risk, and an increase in fiber intake by 10 g/d reduced the risk of gastric cancer by 44%, and reduced the risk of esophageal cancer by 31%. Individuals with the highest intake of whole grains and yellow/orange vegetables had risk factors of 0.53 and 0.58, respectively, compared to those with the lowest intake with regard to the development of upper gastrointestinal cancer [69][70][71][72][73]. The intake of vegetable and fruit fibers, especially green leafy vegetables and cruciferous vegetable fibers, was found to be linked to a reduced risk of non-Hodgkin's lymphoma [74][75].…”