Association between dietary habits and asthma severity in children.

OBJECTIVE To investigate association between dietary habits and asthma severity in children. DESIGN Cross-sectional study. SETTING Two teaching hospitals in Brazil. PARTICIPANTS Cases (n=268) were children (3-12yr) with persistent asthma and age-matched controls (n=126) were those with intermittent asthma. MAIN OUTCOME MEASURES Dietary habits were determined based on food consumption in the past 12 months classified as frequent (≥3 times per week) or infrequent (never or <3 times per week).Nutritional status was classified into two categories according to WHO Child Growth Standards: obese: >2Z-score of BMI-for-age; non-obese: ≤2Z-score of BMI-for-age. RESULTS After adjusting for confounding factors, maternal smoking during pregnancy, preterm birth and obesity were significantly associated with persistent asthma, with adjusted ORs (95% CI) of 2.11 (1.08- 4.13), 2.61(1.07-6.35) and 2.89 (1.49-5.61), respectively. No significant association was observed between frequency of consumption of specific foods, food groups, or dietary pattern (pro- or contra-Mediterranean diet) and the severity of asthma. CONCLUSIONS This study did not find a significant association between dietary habits and asthma severity in children. Maternal smoking during pregnancy, preterm birth and obesity were independent factors associated with persistent asthma.