This double-blind, randomized controlled trial examined the effect of early postnatal fish oil supplementation on infant cellular immune function at six months of age in the context of allergic disease (N = 420). Infants with high atopic risk received fish oil [280 mg docosahexaenoic acid (DHA) and 110 mg eicosapentanoic acid (EPA)] or control oil daily from birth to six months. Blood was collected and analyzed at six months of age in 120 infants and infant allergies were assessed at six and 12 months of age. DHA and EPA levels were significantly higher and erythrocyte arachidonic acid (AA) levels were lower in the fish oil group (all P < 0.05). Infants in the fish oil group had significantly lower IL-13 responses (P = 0.036) to house dust mite and higher IFNγ (P = 0.035) and TNF (P = 0.017) responses to phytohaemaglutinin. Infants with relatively high DHA levels had lower Th2 responses to allergens including lower IL-13 and IL-5 to β-lactoglobulin (P = 0.020 and P = 0.045, respectively). These results suggest that omega-3 fatty acids have immunomodulatory properties (lowered allergen-specific Th2 responses and elevated polyclonal Th1 responses) that are potentially allergyprotective. Clin Exp Allergy. 2012 Aug;42(8):1206-16. PMID: 22805468
