There are few epidemiological data on the dietary risk factors of Barrett's oesophagus, a precursor of oesophageal adenocarcinoma. The present study investigated the association between vegetable, fruit and nitrate intake and Barrett's oesophagus risk in a large prospective cohort. The Netherlands Cohort Study recruited 120 852 individuals aged 55–69 years in 1986. Vegetable and fruit intake was assessed using a 150-item FFQ, and nitrate intake from dietary sources and drinking water was determined. After 16·3 years of follow-up, 433 cases (241 men and 192 women) of Barrett's oesophagus with specialised intestinal metaplasia and 3717 subcohort members were analysed in a case–cohort design using Cox proportional hazards models while adjusting for potential confounders. Men exhibited a lower risk of Barrett's oesophagus in the highest v. the lowest quintile of total (multivariable-adjusted hazard ratio (HR): 0·66, 95 % CI 0·43, 1·01), raw (HR 0·63, 95 % CI 0·40, 0·99), raw leafy (HR 0·55, 95 % CI 0·36, 0·86) and Brassica (HR 0·64, 95 % CI 0·41, 1·00) vegetable intake. No association was found for other vegetable groups and fruits. No significant associations were found between vegetable and fruit intake and Barrett's oesophagus risk among women. Total nitrate intake was inversely associated with Barrett's disease risk in men (HR 0·50, 95 % CI 0·25, 0·99) and positively associated with it in women (HR 3·77, 95 % CI 1·68, 8·45) (P for interaction = 0·04). These results suggest that vegetable intake may contribute to the prevention of Barrett's oesophagus. The possible differential effect in men and women should be evaluated further.

Evidence is accumulating that vitamin D may be protective against carcinogenesis, although exceptions have been observed for some digestive tract neoplasms. The aim of the present study was to explore the association between dietary vitamin D and related nutrients and the risk of oesophageal adenocarcinoma and its precursor conditions, Barrett's oesophagus and reflux oesophagitis. In an all-Ireland case–control study conducted between March 2002 and July 2005, 218 oesophageal adenocarcinoma patients, 212 Barrett's oesophagus patients, 208 reflux oesophagitis patients and 252 population-based controls completed a 101-item FFQ, and provided lifestyle and demographic information. Multiple logistic regression analysis was applied to examine the association between dietary intake and disease risk. Oesophageal adenocarcinoma risk was significantly greater for individuals with the highest compared with the lowest tertile of vitamin D intake (OR 1·99, 95 % CI 1·03, 3·86; P for trend = 0·02). The direct association could not be attributed to a particular vitamin D food source. Vitamin D intake was unrelated to Barrett's oesophagus and reflux oesophagitis risk. No significant associations were observed for Ca or dairy intake and oesophageal adenocarcinoma, Barrett's oesophagus or reflux oesophagitis development. High vitamin D intake may increase oesophageal adenocarcinoma risk but is not related to reflux oesophagitis and Barrett's oesophagus. Ca and dairy product intake did not influence the development of these oesophageal lesions. These findings suggest that there may be population subgroups at an increased risk of oesophageal adenocarcinoma if advice to improve vitamin D intake from foods is implemented. Limited work has been conducted in this area, and further research is required.

Incidence rates for oesophageal adenocarcinoma have increased by over 500 % during the past few decades without clear reasons. Gastro-oesophageal reflux disease, obesity and smoking have been identified as risk factors, although the demographic distribution of these risk factors is not consistent with the demographic distribution of oesophageal adenocarcinoma, which is substantially more common among whites and males than any other demographic groups. Numerous epidemiological studies have suggested associations between dietary factors and the risks of oesophageal adenocarcinoma and its precursor, Barrett's oesophagus, though a comprehensive review is lacking. The main aim of the present review is to consider the evidence linking dietary factors with the risks of oesophageal adenocarcinoma, Barrett's oesophagus, and the progression from Barrett's oesophagus to oesophageal adenocarcinoma. The existing epidemiological evidence is strongest for an inverse relationship between intake of vitamin C, β-carotene, fruits and vegetables, particularly raw fruits and vegetables and dark green, leafy and cruciferous vegetables, carbohydrates, fibre and Fe and the risk of oesophageal adenocarcinoma and Barrett's oesophagus. Patients at higher risk for Barrett's oesophagus and oesophageal adenocarcinoma may benefit from increasing their consumption of fruits and vegetables and reducing their intake of red meat and other processed food items. Further research is needed to evaluate the relationship between diet and the progression of Barrett's oesophagus to oesophageal adenocarcinoma. Evidence from cohort studies will help determine whether randomised chemoprevention trials are warranted for the primary prevention of Barrett's oesophagus or its progression to cancer.