Diet in the aetiology of ulcerative colitis: A European prospective cohort study

Background/Aims: The causes of ulcerative colitis are unknown, although it is plausible that dietary factors are involved. Case-control studies of diet and ulcerative colitis are subject to recall biases. The aim of this study was to examine the prospective relationship between the intake of nutrients and the development of ulcerative colitis in a cohort study. Methods: The study population was 260,686 men and women aged 20-80 years, participating in a large European prospective cohort study (EPIC). Participants were residents in the UK, Sweden, Denmark, Germany or Italy. Information on diet was supplied and the subjects were followed up for the development of ulcerative colitis. Each incident case was matched with four controls and dietary variables were divided into quartiles. Results: A total of 139 subjects with incident ulcerative colitis were identified. No dietary associations were detected, apart from a marginally significant positive association with an increasing percentage intake of energy from total polyunsaturated fatty acids (trend across quartiles OR = 1.19 (95% CI = 0.99-1.43) p = 0.07). Conclusions: No associations between ulcerative colitis and diet were detected, apart from a possible increased risk with a higher total polyunsaturated fatty acid intake. A biological mechanism exists in that polyunsaturated fatty acids are metabolised to pro-inflammatory mediators.