A randomized trial of supplementation with docosahexaenoic acid-rich tuna oil and its effects on the human milk cytokines interleukin 1β, interleukin 6, and tumor necrosis factor α1-3

Background: Increased consumption of n-3 long-chain polyunsaturated fatty acids (PUFAs) has been recommended during pregnancy and lactation. The production of proinflammatory cytokines by human peripheral blood mononuclear cells (PBMCs) can be modified by dietary n-3 PUFAs. Objective: We sought to determine whether dietary supplementation of lactating women with docosahexaenoic acid (DHA) can modulate the concentration of cytokines in the aqueous phase of human milk and the production of cytokines by human milk cells (HMCs) and PBMCs. Design: In this double-blind, prospective, randomized trial, mothers of healthy full-term infants were asked to consume daily a nutritional supplement of 2000 mg oil containing either placebo (n = 40), 300 mg DHA + 70 mg eicosapentaenoic acid (EPA; n = 40), or 600 mg DHA + 140 mg EPA (n = 40). The fatty acid composition of plasma, PBMCs, milk, and HMCs from lactating mothers at 4 wk postpartum was measured by gas chromatography. The concentration of interleukin 6 and tumor necrosis factor a in milk and the production of interleukin 1beta tumor necrosis factor a, and interleukin 6 by PBMCs and HMCs after stimulation with lipopolysaccharide was measured by enzyme-linked immunosorbent assay. Results: At 4 wk postpartum, 82 mothers were still breast-feeding their infants. DHA increases in maternal plasma, PBMCs, milk, and HMCs were proportional to dietary DHA. There was no relation between tissue DHA status and cytokine concentrations. Conclusions: Consumption of less than or equal to600 mg DHA and 140 mg EPA/d for 4 wk increased n-3 PUFA concentrations in relevant tissues but did not cause perturbations in cytokine concentrations in human milk.