No abstract

Postnatal fish oil supplementation improved infant n-3 status but did not prevent childhood allergic disease.

Fetal levels between 50 and 75 nmol/l appeared optimal for minimizing sensitization. While folate taken as a supplement in higher doses during the third trimester was associated with eczema, there was no effect on other allergic outcomes including sensitization. Further studies are needed to determine the significance of this.

Postnatal fish oil supplementation increased infant n-3 polyunsaturated fatty acid (PUFA) levels and associated with lowered allergen-specific Th2 responses and elevated polyclonal Th1 responses. Our results add to existing evidence of n-3 PUFA having immunomodulatory properties that are potentially allergy-protective.

The aim of this study was to determine whether supplementation with fish oil-derived n-3 polyunsaturated fatty acids (n-3 PUFA) during pregnancy modifies placental PUFA composition, the accumulation of specialised pro-resolving lipid mediators (SPMs, specifically resolvins (Rv), protectins (PD) and upstream precursors) and inflammatory gene expression. Placentas were collected from women (nZ51) enrolled in a randomised, placebo controlled trial of n-3 PUFA supplementation from 20-week gestation. Lipids were extracted for fatty acid analysis and SPMs were quantitated by mass spectrometry. Gene expression was determined by qRT-PCR. Using multiple regression analysis, data were correlated for placental n-3 PUFA and SPM levels with PUFA levels in maternal and cord blood erythrocytes. Supplementation with n-3 PUFAs increased placental docosahexaenoic acid (DHA) levels, but not eicosapentaenoic acid (EPA) levels (P!0.05), and increased the levels of the SPM precursors 18-hydroxyeicosapentaenoic acid and 17-hydroxydocosahexaenoic acid (17-HDHA) by two-to threefold (P!0.0005). RvD1, 17R-RvD1, RvD2 and PD1 were detectable in all placentas, but concentrations were not significantly increased by n-3 PUFA supplementation. Placental DHA levels were positively associated with maternal and cord DHA levels (P!0.005), and with placental 17-HDHA concentrations (P!0.0001). Placental mRNA expression of PTGS2, IL1b, IL6 and IL10 was unaffected by n-3 PUFA supplementation, but TNFa expression was increased by 14-fold (P!0.05). We conclude that n-3 PUFA supplementation in pregnancy i) enhances placental accumulation of DHA and SPM precursors, ii) does not alter placental EPA levels, and iii) has no stimulatory effects on inflammatory gene expression. Further studies are required to ascertain the biological significance of SPMs in the placenta and the potential immunomodulatory effects of elevating placental SPM levels.

n-3 Long-chain PUFA (LC-PUFA) intake during infancy is important for neurodevelopment; however, previous studies of n-3 LC-PUFA supplementation have been inconclusive possibly due to an insufficient dose and limited methods of assessment. The present study aimed to evaluate the effects of direct supplementation with high-dose fish oil (FO) on infant neurodevelopmental outcomes and language. In the present randomised, double-blind, placebo-controlled trial, 420 healthy term infants were assigned to receive a DHA-enriched FO supplement (containing at least 250 mg DHA/d and 60 mg EPA/d) or a placebo (olive oil) from birth to 6 months. Assessment occurred at 18 months via the Bayley Scales of Infant and Toddler Development (3rd edition; BSID-III) and the Child Behavior Checklist. Language assessment occurred at 12 and 18 months via the Macarthur -Bates Communicative Development Inventory. The FO group had significantly higher erythrocyte DHA (P¼0·03) and plasma phospholipid DHA (P¼ 0·01) levels at 6 months of age relative to placebo. In a small subset analysis (about 40 % of the total population), children in the FO group had significantly higher percentile ranks of both later developing gestures at 12 and 18 months (P¼ 0·007; P¼ 0·002, respectively) and the total number of gestures (P¼ 0·023; P¼ 0·006, respectively). There was no significant difference between the groups in the standard or composite scores of the BSID-III. The results suggest that improved postnatal n-3 LC-PUFA intake in the first 6 months of life using high-dose infant FO supplementation was not beneficial to global infant neurodevelopment. However, some indication of benefits to early communicative development was observed.

This suggests that improving 25(OH)D3 status in pregnancy or early infancy may reduce the development of allergic disease in high-risk infants by inhibiting cytokine profiles associated with allergy. Results of clinical trials are awaited to determine the efficacy of vitamin D supplementation in allergy prevention.

Increased maternal egg ingestion is associated with increased breastmilk ovalbumin, and markers of immune tolerance in infants. These results highlight the potential for maternal diet to benefit infant oral tolerance development during lactation.