Food Intolerance: Associations with the rs12212067 Polymorphism of FOXO3 in Crohn's Disease Patients in New Zealand.

Background: Diet is known to play a major role in Crohn's disease (CD). It has also been reported that the minor G allele from the rs12212067 polymorphism (T>G) in FOXO3 is associated with milder CD. The aim of this study was to investigate the association between the rs12212067 polymorphism and food intolerances for a total of 253 foods.

Methods: Tolerances and intolerances were recorded on a self-reported dietary questionnaire. Each food was scored on a 5-point ordinal scale: beneficial effects as '+ +' or '+', adverse effects as '- -' or '-', and 'makes no difference' as '='. Dietary and genotype data were available for a total of 283 CD patients.

Results: We identified 17 foods with beneficial effects in our study which were significantly associated with the G allele of the FOXO3 rs12212067 polymorphism. Of these, sweet potatoes had the highest reported frequency of beneficial responses. We also identified 4 foods with detrimental effects in more than 25% of our study population. These were mustard, wasabi, and raw and cooked tomatoes, which again were significantly associated with the G allele in FOXO3.

Conclusions: There was strong evidence that adverse effects of mustard, wasabi, and raw and cooked tomatoes were significantly associated with the G allele of FOXO3 and that these foods should be avoided by people carrying this allele.