**Abstract**

Daily supplementation of maternal diet during pregnancy and lactation with a fish oil-enriched dairy product increases the percentage of DHA and other omega-3 (ω-3) long-chain polyunsaturated fatty acids (LCPUFAs) in mothers (placenta, plasma, erythrocyte membranes, and breast milk) and children (plasma and erythrocyte membranes). This supplementation during critical periods such as pregnancy, lactation, and early development of a newborn may influence the levels of certain inflammatory cytokines, reducing pro-inflammatory cytokines and promoting an anti-inflammatory "environment". In pregnant women who have not received any supplement of omega-3 LCPUFAs, IL-6 plasma levels are higher, while TNF-alpha plasma levels are also higher in their breastfed infant at birth and 2 months thereafter. There could be a relationship between docosahexaenoic acid (DHA) and the concentrations of different cytokines.

**Keywords:** docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), omega-3 LCPUFAs, pregnancy, lactation, cytokines, fatty acids

#### **1. Introduction**

Interest in the therapeutic effects of omega-3 (ω-3) fatty acids has grown over the last 30 years, particularly in regard to visual and neurological development in newborns, the immune system, and inflammatory and cardiovascular diseases [1–9].

Inflammation is one of the principal causes of complications during pregnancy and of prematurity and neonatal morbidity [10–15].

Docosahexaenoic acid (DHA) has anti-inflammatory effects and can alter the production of inflammatory cytokines in animal models, cell culture, and in humans [16–26]. A high intake of omega-3 fatty acids has been associated with a reduction in arachidonic acid-derived inflammatory eicosanoids, cytokine production, reactive oxygen species, and expression of adhesion molecules [27]. It is also associated with the production of lipid mediators [28] that have anti-inflammatory [29–31] and immunomodulatory effects [27]. Both eicosapentaenoic acid (EPA) and DHA affect the function of many immune cells and can have a beneficial effect in preventing inflammatory or immune-mediated diseases, but their effects and mechanisms of action can differ [32]. They can inhibit the production of pro-inflammatory cytokines such as tumour necrosis factor-alpha and interleukin (IL)-1 and IL-6 [33]. In animal models their intake during pregnancy appears to exert an anti-inflammatory effect on damaged tissue in the young [34–36], while in humans it produces a decrease in Th1 cytokines such as interferon-gamma (IFN-γ)

and IL-1 in infants' plasma and a decrease in the Th2 cytokines IL-14 and IL-13 in the umbilical cord blood [32, 37].
