Fatty Acids in Breast Milk Associated with Asthma-Like Symptoms and Atopy in Infancy: A Longitudinal Study

Abstract

Objective. The relationship between fatty acids (FAs) in breast milk and the risk of childhood allergies is controversial. We prospectively investigated the relationship between FAs in colostrum and breast milk and asthma-like symptoms (AS) and atopy in infancy. Methods. Pregnant women were recruited in Columbia and Charleston, South Carolina. Colostrum and mature milk samples were collected. The concentrations of n-3 FAs (eicosapentaenoic acid, α-linolenic acid, docosapentaenoic acid, and docosahexaenoic acid) and n-6 FAs (linoleic acid, arachidonic acid, and eicosadienoic acid) were determined by gas chromatography. AS were ascertained at 6 and 12 months of age and atopy (skin prick test) at 12 months. FAs were dichotomized (high vs. median and low). Generalized estimating equations were used to determine the effect of FAs on repeated AS, compensating for intra-individual correlations and adjusting for confounders. Log-linear regression was used to analyze atopy. Results. FAs were analyzed in 24 colostrum and 78 breast milk samples. High levels of total n-6 (lipid based) FAs in breast milk were associated with an increased risk of AS in infants (risk ratio (RR) = 2.91; 95% confidence interval (CI): 1.37, 6.18), even after controlling for total n-3 FAs (RR = 2.07, 95% CI: 1.12, 3.85). High levels of total n-3 FAs controlling for n-6 FAs decreased the risk of atopy at the age of 12 months. Conclusions. High levels of total n-6 polyunsaturated fatty acids (PUFAs) in breast milk are associated with an increased risk for AS, whereas high levels of total n-3 PUFAs decreased the risk of atopy. These data suggest that the effects of n-3 and n-6 PUFAs on allergic disorders should be further explored.

• human milk
• omega-3
• omega-6
• skin prick testing

Acknowledgments

We gratefully acknowledge the cooperation of the women who participated in this study. We thank the Breastfeeding and Child Health (BACH) and Pregnancy Environment and Child Health (PEACH) study team. We would like to acknowledge Denise Altman for her insightful comments and helping with the recruitment of participants.

This study was funded by the Thrasher Research Foundation (Award Number 02826–6), and in part by the National Institutes of Health grant P30DK056350 to the UNC-CH Nutrition Obesity Research Center. Initial participant enrollment was supported by a grant from the US Environmental Protection Agency (R830825-01-0).

Declaration of Interest

The authors declare no conflicts of interest.