Consumption of spicy foods and the prevalence of irritable bowel syndrome

Aim: To explore the association between consumption of spicy foods and prevalence of irritable bowel syndrome (IBS) among Iranian adults.

Methods: In this cross-sectional study, data from 4763 Iranian adult participants were used. Consumption of spicy foods was estimated using a dietary habits questionnaire that included a question on spicy foods consumption: "how frequently do you use spicy foods (pepper, curry, ginger, cinnamon and turmeric) during a week?" Participants could respond to the question by choosing one of these choices: never, 1-3 times, 4-6 times, 7-9 times, or more than 10 times per week. A modified Persian version of the Rome III questionnaire was used to determine the prevalence of IBS.

Results: IBS was prevalent in 21.7% (18.6% of men and 24.1% of women) of the study population. After controlling for potential confounders including dietary behaviors, those consuming spicy foods ≥ 10 times per week were 92% more likely to have IBS compared with those who never consumed spicy foods (OR = 1.92; 95%CI: 1.23-3.01, P trend < 0.01). The association remained significant even after taking lactose intolerance into account (OR = 1.85; 95%CI: 1.18-2.90, P trend < 0.01). Stratified analysis by gender revealed that the association between consumption of spicy foods and IBS was not significant in men; however, a significant association was found among women after taking potential cofounders, including meal regularity and lactose intolerance, into account. Women who consumed spicy foods ≥ 10 times per week were two times more likely to have IBS compared with those who never consumed spicy foods (OR = 2.03; 95%CI: 1.09-3.77, P trend = 0.02).

Conclusion: Consumption of spicy foods is directly associated with IBS, particularly in women. Further, prospective studies are warranted to (1) examine this association in other populations; and (2) evaluate whether dietary interventions, for example a reduction in spice consumption, would improve IBS symptoms.