Dietary inflammatory index and risk of reflux oesophagitis, Barrett's oesophagus and oesophageal adenocarcinoma: a population-based case-control study

The dietary inflammatory index (DIITM) is a novel composite score based on a range of nutrients and foods known to be associated with inflammation. DII scores have been linked to the risk of a number of cancers, including oesophageal squamous cell cancer and oesophageal adenocarcinoma (OAC). Given that OAC stems from acid reflux and that the oesophageal epithelium undergoes a metaplasia-dysplasia transition from the resulting inflammation, it is plausible that a high DII score (indicating a pro-inflammatory diet) may exacerbate risk of OAC and its precursor conditions. The aim of this analytical study was to explore the association between energy-adjusted dietary inflammatory index (E-DIITM) in relation to risk of reflux oesophagitis, Barrett's oesophagus and OAC. Between 2002 and 2005, reflux oesophagitis (n 219), Barrett's oesophagus (n 220) and OAC (n 224) patients, and population-based controls (n 256), were recruited to the Factors influencing the Barrett's Adenocarcinoma Relationship study in Northern Ireland and the Republic of Ireland. E-DII scores were derived from a 101-item FFQ. Unconditional logistic regression analysis was applied to determine odds of oesophageal lesions according to E-DII intakes, adjusting for potential confounders. High E-DII scores were associated with borderline increase in odds of reflux oesophagitis (OR 1·87; 95 % CI 0·93, 3·73), and significantly increased odds of Barrett's oesophagus (OR 2·05; 95 % CI 1·22, 3·47), and OAC (OR 2·29; 95 % CI 1·32, 3·96), when comparing the highest with the lowest tertiles of E-DII scores. In conclusion, a pro-inflammatory diet may exacerbate the risk of the inflammation-metaplasia-adenocarcinoma pathway in oesophageal carcinogenesis.