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

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 in milk and the production of interleukin 1ß, tumor necrosis factor , 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 600 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.Joanna S Hawkes, Dani-Louise Bryan, Maria Makrides, Mark A Neumann, and Robert A Gibso

Replacement of fish oil with rapeseed oil in diets of Atlantic salmon (Salmo salar) affects tissue lipid compositions and hepatocyte fatty acid metabolism

Duplicate groups of Atlantic salmon post-smolts were fed five practical-type diets in which the added lipid was 100% fish oil [FO; 0% rapeseed oil (0% RO)], 90% FO + 10% RO (10% RO), 75% FO + 25% RO (25% RO), 50% FO + 50% RO (50% RO) or 100% RO, for a period of 17 wk. There were no effects of diet on growth rate or feed conversion nor were any histopathological lesions found in liver, heart, muscle or kidney. The greatest accumulation of muscle lipid was in fish fed 0% RO, which corresponded to significantly lower muscle protein in this group. The highest lipid levels in liver were found in fish fed 100% RO. Fatty acid compositions of muscle lipid correlated with RO inclusion in that the proportions of 18:1(n-9), 18:2(n-6) and 18:3(n-3) all increased with increasing dietary RO (r = 0.98–1.00, P less than 0.013). The concentrations of eicosapentaenoic acid [20:5(n-3)] and docosahexaenoic acid [22:6(n-3)] in muscle lipid were significantly reduced (P less than 0.05), along with total saturated fatty acids, with increasing dietary RO. Diet-induced changes in liver fatty acid compositions were broadly similar to those in muscle. Hepatic fatty acid desaturation and elongation activities, measured using [1-14C] 18:3(n-3), were increased with increasing dietary RO. Limited supplies of marine fish oils require that substitutes be found if growth in aquaculture is to be maintained such that fish health and product quality are not compromised. Thus, RO can be used successfully as a substitute for fish oil in the culture of Atlantic salmon in sea water although at levels of RO greater than 50% of dietary lipid, substantial reductions occur in muscle 20:5(n-3), 22:6(n-3) and the (n-3)/(n-6) polyunsaturated fatty acid (PUFA) ratio, which will result in reduced availability of the (n-3) highly unsaturated fatty acids that are beneficial for human health