Dietary and Plasma Polyunsaturated Fatty Acids Are Inversely Associated with Asthma and Atopy in Early Childhood.

Background: Polyunsaturated fatty acids (PUFAs) influence immune function and risk of allergic disease. Prior evidence of the effect of PUFA intake on childhood asthma and allergy is inconclusive.

Objectives: To investigate associations of PUFA plasma levels and dietary intake with asthma and allergy at age 3 years in this ancillary study of the Vitamin D Antenatal Asthma Reduction Trial.

Methods: Plasma PUFA levels were reported as relative abundances from mass spectrometry profiling, and dietary PUFA intake was derived from food frequency questionnaire responses. Associations between PUFA and outcomes, including asthma and/or recurrent wheeze, allergic sensitization, and total IgE at age 3 years, were evaluated in adjusted regression models. Additional regression models analyzed the combined effects of antenatal vitamin D and early childhood PUFA on outcomes.

Results: Total, omega-3, and omega-6 plasma PUFA relative abundances were significantly (P < .05) inversely associated with both asthma and/or recurrent wheeze and allergic sensitization. Likewise, dietary PUFA intake was inversely associated with asthma and/or recurrent wheeze (P < .05 for omega-6 PUFA only). For both dietary and plasma measures of total, omega-3, and omega-6 PUFAs, inverse associations with outcomes were strongest among subjects with both high umbilical cord blood 25-hydroxyvitamin D and high PUFA at age 3 years.

Conclusions: PUFA dietary intake and plasma levels are inversely associated with asthma and/or recurrent wheeze and atopy at age 3 years. Antenatal vitamin D could modulate the effect of early childhood PUFA on risk of asthma and allergy.