Serum fatty acids in infants, reflecting family fish consumption, were inversely associated with allergy development but not related to farm residence.

AIM: In this study, differences in serum fatty acid patterns between farm and non-farm infants were investigated and related to subsequent allergy development. We also related allergy-related serum fatty acids to maternal diet and breast milk fatty acids. METHODS: The FARMFLORA birth cohort included 28 farm and 37 non-farm infants. Serum was obtained from 21 farm infants and 29 controls at four months postpartum and analysed for phospholipid fatty acids. Allergy was diagnosed by paediatricians at three years of age. RESULTS: Serum fatty acid patterns were similar in farm and control infants, although farm infants had lower 18:1 omega-7 proportions. Serum proportions of eicosapentaenoic acid (EPA) were unrelated to farming status, but lower in children who subsequently developed allergy, with an odds ratio of 0.47 and 95% confidence interval of 0.27-0.83 (p=0.01) for every 0.1% EPA increase. The infants' serum EPA proportions correlated with breast milk EPA proportions, which, in turn, correlated with maternal oily fish intake during lactation. CONCLUSION: The allergy protective effect of farming was not linked to infant serum fatty acid composition. However, healthy infants had higher proportions of EPA in their sera, probably reflecting a family diet rich in fish, compared to subsequently allergic children.