The influence of the dietary intake of fatty acids and antioxidants on hay fever in adults

Background: The objective of the investigation was to explore in a prospective study the associations between dietary intake of fatty acids, antioxidants and hay fever manifestation in adulthood. Methods: Three hundred and thirty-four hay fever cases with adult onset of clinical symptoms from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort were identified during follow-up and matched with 1336 controls. Dietary intake data were obtained by means of validated food frequency questionnaires. The influence of dietary fatty acid and vitamin intake on hay fever risk was estimated by means of unconditional logistic regression. Results: High intake of oleic acid was positively associated with hay fever [odds ratio (OR): 2.86, 95% confidence intervals (95% CI): 1.22-6.70], whereas high intake of eicosapentaenoic acid was inversely related to hay fever (OR: 0.45, 95% CI: 0.22-0.93). Furthermore, high beta-carotene intake increased the risk of hay fever (OR: 1.69, 95% CI: 1.09-2.63) while increasing intake of vitamin E was a protective factor (OR: 0.38, 95% CI: 0.17-0.85). In grouped analyses, the effects of beta-carotene and vitamin E were mainly observed among women and ex-/current-smokers; in these subgroups, linoleic acid increased the risk of hay fever. Conclusions: In conclusion, the present results provide further evidence that dietary factors might affect the risk of clinical manifestation of hay fever. However, the effects in smokers and women may suggest different biological mechanisms for the investigated nutrients, which need further research.