Dietary intake of fatty acids, antioxidants and selected food groups and asthma in adults

OBJECTIVE: Within a prospective study, we explored the associations between dietary intake of fatty acids, antioxidants and relevant food sources of these nutrients on the clinical manifestation of asthma in adulthood. METHOD: A total of 105 newly physician-diagnosed cases of asthma from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort were identified during follow-up and matched with 420 controls. Baseline dietary intake was obtained by means of validated food frequency questionnaires. The association of dietary intake variables and asthma risk was explored by unconditional logistic regression models. RESULTS: A high intake of oleic acid (C18:1 n-9) was positively associated with asthma (P-value for trend 0.035), while no significant associations were found for the other dietary fatty acids. Most prominently, a high margarine intake increased the risk of onset of asthma in adulthood (adjusted odds ratio (OR) 3rd tertile: 1.73 (95% confidence interval (95% CI): 1.05-2.87), P for trend=0.050), the effect being stronger in men (2nd tertile: OR=1.66, 3rd tertile: OR=2.51) than in women (2nd tertile: OR=0.91; 3rd tertile: OR=1.47). The dietary intake of antioxidants and their main food sources had no effect on asthma risk. CONCLUSIONS: In summary, the present results provide evidence that even in adulthood a high margarine intake increases the risk of clinical onset of asthma. Whether oleic acid may serve as a proxy for margarine-derived trans-fatty acids (C18:1 t9) remains to be clarified.