Intake of antioxidants during pregnancy and the risk of allergies and asthma in the offspring.

BACKGROUND/OBJECTIVES: The potential immune functions related to the damages induced by oxygen-free radicals suggest that antioxidants may have a role in the development of allergies. The objective was to investigate the association between maternal intake of antioxidants during pregnancy and the risk of asthma, rhinitis and eczema in 5-year-old children.

SUBJECTS/METHODS: This study was on the basis of the Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study, a population-based birth cohort study with 5-year follow-up. Complete information on maternal food frequency questionnaire data and ISAAC (International Study of Asthma and Allergies in Childhood)-based allergic outcomes were available for 2441 children. Cox proportional regression and logistic regression were used for the analyses.

RESULTS: Maternal intake of any of the antioxidants was not significantly associated with the risk of asthma, rhinitis or eczema in the offspring, except for dietary intake of magnesium, which was independently associated with protection against eczema (OR 0.78; 95% CI 0.62-0.97).

CONCLUSION: Maternal intake of dietary magnesium during pregnancy may protect against the risk of eczema in the offspring. We did not confirm previous observations concerning other antioxidants. This may be due to the variable amount of antioxidant intake across studies and also indicative of the hypothesis that there may be a critical time window in pregnancy during which antioxidants might modify the risk of allergies in the offspring.