Plasma lipid and apolipoprotein concentrations in full term infants fed formula supplemented with long-chain polyunsaturated fatty acids and cholesterol

Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy

BACKGROUND

Early dietary intakes may influence the development of allergic disease. It is important to determine if dietary polyunsaturated fatty acids (PUFAs) given as supplements or added to infant formula prevent the development of allergy.

OBJECTIVES

To determine the effect of higher PUFA intake during infancy to prevent allergic disease.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 9), MEDLINE (1966 to 14 September 2015), EMBASE (1980 to 14 September 2015) and CINAHL (1982 to 14 September 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the use of a PUFA with no PUFA in infants for the prevention of allergy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality and extracted data from the included studies. We used fixed-effect analyses. The treatment effects were expressed as risk ratio (RR) with 95% confidence intervals (CI). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

The search found 17 studies that assessed the effect of higher versus lower intake of PUFAs on allergic outcomes in infants. Only nine studies enrolling 2704 infants reported allergy outcomes that could be used in meta-analyses. Of these, there were methodological concerns for eight.In infants up to two years of age, meta-analyses found no difference in incidence of all allergy (1 study, 323 infants; RR 0.96, 95% CI 0.73 to 1.26; risk difference (RD) -0.02, 95% CI -0.12 to 0.09; heterogeneity not applicable), asthma (3 studies, 1162 infants; RR 1.04, 95% CI 0.80 to 1.35, I² = 0%; RD 0.01, 95% CI -0.04 to 0.05, I² = 0%), dermatitis/eczema (7 studies, 1906 infants; RR 0.93, 95% CI 0.82 to 1.06, I² = 0%; RD -0.02, 95% CI -0.06 to 0.02, I² = 0%) or food allergy (3 studies, 915 infants; RR 0.81, 95% CI 0.56 to 1.19, I² = 63%; RD -0.02, 95% CI -0.06 to 0.02, I² = 74%). There was a reduction in allergic rhinitis (2 studies, 594 infants; RR 0.47, 95% CI 0.23 to 0.96, I² = 6%; RD -0.04, 95% CI -0.08 to -0.00, I² = 54%; number needed to treat for an additional beneficial outcome (NNTB) 25, 95% CI 13 to ∞).In children aged two to five years, meta-analysis found no difference in incidence of all allergic disease (2 studies, 154 infants; RR 0.69, 95% CI 0.47 to 1.02, I² = 43%; RD -0.16, 95% CI -0.31 to -0.00, I² = 63%; NNTB 6, 95% CI 3 to ∞), asthma (1 study, 89 infants; RR 0.45, 95% CI 0.20 to 1.02; RD -0.20, 95% CI -0.37 to -0.02; heterogeneity not applicable; NNTB 5, 95% CI 3 to 50), dermatitis/eczema (2 studies, 154 infants; RR 0.65, 95% CI 0.34 to 1.24, I² = 0%; RD -0.09 95% CI -0.22 to 0.04, I² = 24%) or food allergy (1 study, 65 infants; RR 2.27, 95% CI 0.25 to 20.68; RD 0.05, 95% CI -0.07 to 0.16; heterogeneity not applicable).In children aged two to five years, meta-analysis found no difference in prevalence of all allergic disease (2 studies, 633 infants; RR 0.98, 95% CI 0.81 to 1.19, I² = 36%; RD -0.01, 95% CI -0.08 to 0.07, I² = 0%), asthma (2 studies, 635 infants; RR 1.12, 95% CI 0.82 to 1.53, I² = 0%; RD 0.02, 95% CI -0.04 to 0.09, I² = 0%), dermatitis/eczema (2 studies, 635 infants; RR 0.81, 95% CI 0.59 to 1.09, I² = 0%; RD -0.04 95% CI -0.11 to 0.02, I² = 0%), allergic rhinitis (2 studies, 635 infants; RR 1.02, 95% CI 0.83 to 1.25, I² = 0%; RD 0.01, 95% CI -0.06 to 0.08, I² = 0%) or food allergy (1 study, 119 infants; RR 0.27, 95% CI 0.06 to 1.19; RD -0.10, 95% CI -0.20 to -0.00; heterogeneity not applicable; NNTB 10, 95% CI 5 to ∞).

AUTHORS' CONCLUSIONS

There is no evidence that PUFA supplementation in infancy has an effect on infant or childhood allergy, asthma, dermatitis/eczema or food allergy. However, the quality of evidence was very low. There was insufficient evidence to determine an effect on allergic rhinitis.

The enrichment of hen eggs with omega-3 fatty acids

A study was conducted to determine the omega-3 fatty acid compositions of enriched eggs obtained from hens by feeding flaxseed and fish oil. Laying hens were fed a diet containing fish oil (FOD) (1.5%) or a mixture of flaxseed (10%) and fish oil (FFOD) (1.5%) for 15 and 30 days. Another group was fed commercial diet as a control. Eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) were not determined in the control group's eggs. However, the EPA level was 0.87% and 0.82% in the FOD group's eggs and 0.49% and 0.55% in the FFOD group's eggs, obtained after a 15- and 30-day feeding period, respectively. Corresponding values for DPA were 0.45% and 0.50% in the FOD group's eggs and 0.41% and 0.44% in the FFOD group's eggs. Docosahexaenoic acid contents of eggs obtained from the FOD group were 4.85% and 4.92% after a 15- and 30-day feeding period, respectively, compared with 3.29% and 3.91% in the FFOD group's eggs and 1.03% in the control group's eggs. The alpha-linolenic acid content of eggs was 0.45% and 0.49% in the FOD group's eggs after a 15- and 30-day feeding period, respectively, and 0.43% in the control group's eggs, whereas it was 3.61% and 4.10%, respectively, in the FFOD group's eggs.

Fish oil affects blood pressure and the plasma lipid profile in healthy Danish infants

Animal and epidemiologic studies indicate that early nutrition has lasting effects on metabolism and cardiovascular disease risk. In adults, (n-3) long-chain PUFA (LCPUFA) from fish oils improve blood pressure, the lipid profile, and possibly cardiovascular disease mortality. This randomized trial is the first to investigate the effects of fish oil on blood pressure and the lipid profile in infancy. Healthy term 9-mo old infants (n = 83) were randomly assigned to 5 mL fish oil daily or no fish oil for 3 mo and to 2 different milk types. Before and after the intervention, blood pressure was measured with an oscillometric device, and blood was sampled for analysis of erythrocyte fatty acid composition and the plasma lipid profile. This paper examines the effects of the fish oil supplement, with adjustment for the effects of the milk intervention when relevant. The fish oil intervention increased erythrocyte (n-3) LCPUFA content (P < 0.001). At 12 mo, infants administered fish oil had a lower systolic blood pressure [adjusted mean difference (95% CI)] 6.3 mm Hg (0.9, 11.7) (P = 0.02), a 0.51 mmol/L (0.07, 0.95) higher plasma total cholesterol (P = 0.02), and a 0.52 mmol/L (0.02,1.01) higher LDL cholesterol (P = 0.04) than infants not administered fish oil. Plasma triacylglycerol was inversely associated with the erythrocyte content of eicosapentaenoic acid (r = 0.34, P < 0.01), a biomarker of fish oil dose. The observed effects of fish oil are in accordance with findings in adults. The long-term health implications warrant further investigation.

Influence of dietary cholesterol on vitamin d metabolism in formula-fed preterm neonates

OBJECTIVES

Supplementation of preterm formulas with cholesterol could help to mimic the fat composition of human milk. However, this could possibly influence vitamin D 25-hydroxylation because this reaction is catalyzed in part by the mitochondrial cytochrome P-450, the enzyme responsible for the 27-hydroxylation of cholesterol. The purpose of this study was to verify whether the addition of cholesterol to preterm formulas could interfere with vitamin D metabolism in preterm neonates.

METHODS

In a prospective study, 30 preterm neonates were randomly assigned to a low (< 0.03 g/L), medium (0.15 g/L), or high (0.30 g/L) cholesterol-content preterm formula until theoretical term (i.e., 40 weeks post-conceptional age). Anthropometric data and serum hydroxy-vitamin D and 1,25 dihydroxy-vitamin D concentrations were measured at study entry and theoretical term. In a subgroup of 14 subjects, serum cholesterol and lymphocyte 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA were also assessed.

RESULTS

(median [25, 75 centiles]): At theoretical term, there were no significant differences in serum hydroxy-vitamin D concentrations among the three groups, even after adjustment for confounding variables (65 [50, 78] nmol/L, 79 [59, 86] nmol/L, and 67 [43, 103] nmol/L, respectively, = 0.65) or 1,25 dihydroxy-vitamin D ( = 0.88). Furthermore, there were no significant differences in 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA copy numbers.

CONCLUSIONS

In preterm neonates fed formulas with a cholesterol content similar to or higher than that of human milk, we did not observe deleterious effects on vitamin D metabolism. However, long-term effects of cholesterol supplementation require further studies.

Physiological aspects of human milk lipids

Human milk from healthy and well-nourished mothers is the preferred form of feeding for all healthy newborn infants. The nutrient supply with human milk supports normal growth and development of the infant. Here the general characteristics of human milk lipids and recent knowledge on lactational physiology, composition and functional aspects of human milk lipids are discussed. Lipids in human milk represent the main source of energy for the breastfed baby and supply essential nutrients such as fat-soluble vitamins and polyunsaturated fatty acids (PUFA). The essential fatty acids linoleic and alpha-linolenic acids (LA and ALA) are precursors of long-chain polyunsaturated fatty acids (LC-PUFA), including arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) acids (AA and DHA). LC-PUFA serve as indispensable structural components of cellular membranes and are deposited to a considerable extent in the growing brain and the retina during perinatal development. The supply of preformed LC-PUFA with human milk lipids has been related to functional outcomes of the recipient infants such as visual acuity and development of cognitive functions during the first year of life. Recent stable isotope studies indicate that the major portion of milk PUFA is not derived directly from the maternal diet, but stems from endogenous body stores. Thus, not only the woman's current but also her long-term dietary intake is of marked relevance for milk fat composition.

Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants

Several studies have reported that feeding gamma-linolenic acid (GLA) has resulted in no increase in arachidonic acid (AA) in newborns. This result was ascribed to the eicosapentaenoic acid (EPA)-rich fish oil used in these formulas. Docosahexaenoic acid (DHA) sources with only minor amounts of EPA are now available, thus the addition of GLA to infant formulas might be considered an alternative to AA supplementation. Sixty-six premature infants were randomized to feeding one of four formulas [ST: no GLA, no long-chain polyunsaturated fatty acids; BO: 0.6% GLA (borage oil); BO + FOLOW: 0.6% GLA, 0.3% DHA, 0.06% EPA; BO + FOHIGH: 0.6% GLA, 0.3% DHA, 0.2% EPA] or human milk (HM, nonrandomized) for 4 wk. Anthropometric measures and blood samples were obtained at study entry and after 14 and 28 d. There were no significant differences between groups in anthropometric measures, tocopherol, and retinol status at any of the studied time points. The AA content of plasma phospholipids was similar between groups at study start and decreased significantly until day 28 in all formulafed groups, but not in the breast-fed infants [ST: 6.6 +/- 0.2%, BO: 6.9 +/- 0.3%, BO + FOLOW: 6.9 +/- 0.4%, BO + FOHIGH: 6.7 +/- 0.2%, HM: 8.6 +/- 0.5%, where values are reported as mean +/- standard error; all formulas significantly different (P< 0.05) from HM]. There was no significant influence of GLA or fish oil addition to the diet. GLA had only a very limited effect on AA status which was too small to obtain satisfactory concentrations (concentrations similar to breast-fed babies) under the circumstances tested. The effect of GLA on AA is independent of the EPA and DHA content in the diet within the dose ranges studied.