Atopic sensitization during the first year of life in relation to long chain polyunsaturated fatty acid levels in human milk

Sialic acid and food allergies: The link between nutrition and immunology

Food allergies (FA), a major public health problem recognized by the World Health Organization, affect an estimated 3%-10% of adults and 8% of children worldwide. However, effective treatments for FA are still lacking. Recent advances in glycoimmunology have demonstrated the great potential of sialic acids (SAs) in the treatment of FA. SAs are a group of nine-carbon α-ketoacids usually linked to glycoproteins and glycolipids as terminal glycans. They play an essential role in modulating immune responses and may be an effective target for FA intervention. As exogenous food components, sialylated polysaccharides have anti-FA effects. In contrast, as endogenous components, SAs on immunoglobulin E and immune cell surfaces contribute to the pathogenesis of FA. Given the lack of comprehensive information on the effects of SAs on FA, we reviewed the roles of endogenous and exogenous SAs in the pathogenesis and treatment of FA. In addition, we considered the structure-function relationship of SAs to provide a theoretical basis for the development of SA-based FA treatments.

The Sources of Essential Fatty Acids for Allergic and Cancer Patients; a Connection with Insight into Mammalian Target of Rapamycin: A Narrative Review

Background:

Disturbance in essential fatty acids (EFA) metabolism plays a key role in autoimmune diseases, but EFA supplementation with sources of borage, evening primrose, hemp seed and fish oils was not effective in atopic and cancer diseases, as that seen in the case of multiple sclerosis. It seems that two complexes of the mammalian target of rapamycin (mTOR) signaling, mTORC1 and mTORC2, are congruent with the two bases of the Traditional Iranian Medicine (TIM) therapy, Cold and Hot nature, which are essential for the efficacy of functional oils for controlling immune responses in autoimmune diseases.

Methods:

We searched PubMed database, Web of Science (WOS), Google Scholar, Scopus and selected studies by predefined eligibility criteria. We then assessed their quality and extracted data.

Results:

The oils controlled by Cold or Hot nature may be helpful in maintaining homeostasis and preventing autoimmune diseases. In summary, studies of randomized controlled trials for allergy and cancer patients found no improvement in the signs or response to tests, despite a remarkable change in EFA fractions in the blood by supplementation with sources of borage, evening primrose, hemp seed and fish oils. In contrast, portulaca oleracea oil exhibited protective effects by anti-inflammatory properties via the PI3K/Akt/mTORC2 pathway with a deviation immune response to Th1 to treat atopic diseases and cancer.

Conclusions:

According to the concept of Traditional Iranian Medicine therapy, in contrast to Cold-nature oils, EFA supplementation with the sources of Hot-nature oilsis not suitable for the treatment of atopic and cancerous diseases.

Association of breast milk fatty acids with allergic disease outcomes-A systematic review

INTRODUCTION

Dietary polyunsaturated fatty acids (PUFAs) have immunoregulatory properties. Breast milk is rich in PUFA, and it has been hypothesized that these PUFAs may be important in the aetiology of allergic diseases. Despite a growing body of evidence, the associations between breast milk PUFA and allergic disease have not previously been systematically reviewed.

METHODS

The search was performed in PubMed and EMBASE databases using breastfeeding, fatty acid and allergic disease terms. Two authors were involved in selecting papers for review according to the inclusion criteria and extracting information on study characteristics and measures of association. Only studies that reported numeric associations between concentration of breast milk fatty acids and allergic disease outcomes were included.

RESULTS

A total of 18 papers met the inclusion criteria, reporting results from 15 study populations. The majority were cohort studies (n=11), with data from only two case-control and two cross-sectional studies. Sample size varied between 30 and 352 participants, and follow-up time of the cohorts varied between 3 months and 14 years. Nine studies reported on eczema, seven reported on sensitization, and only five reported on asthma/wheeze. There was heterogeneity among studies in terms of presenting the association between PUFA and allergy; therefore, estimates could not be pooled. Only a few studies observed associations between n-3 and n-6 PUFAs and allergic disease, and the magnitude of this effect varied greatly.

CONCLUSIONS

There is insufficient evidence to suggest that colostrum or breast milk polyunsaturated fatty acids influence the risk of childhood allergic diseases.

They Are What You Eat: Can Nutritional Factors during Gestation and Early Infancy Modulate the Neonatal Immune Response?

The ontogeny of the human immune system is sensitive to nutrition even in the very early embryo, with both deficiency and excess of macro- and micronutrients being potentially detrimental. Neonates are particularly vulnerable to infectious disease due to the immaturity of the immune system and modulation of nutritional immunity may play a role in this sensitivity. This review examines whether nutrition around the time of conception, throughout pregnancy, and in early neonatal life may impact on the developing infant immune system.

High levels of omega-3 fatty acids in milk from omega-3 fatty acid-supplemented mothers are related to less immunoglobulin E-associated disease in infancy

AIM

We previously reported a protective effect of maternal omega-3 fatty acid supplements on the development of immunoglobulin E (IgE)-associated disease in infancy. This study assessed omega-3 long-chain polyunsaturated fatty acids (LCPUFA) in maternal milk in relation to omega-3 LCPUFA supplementation and the development of allergic disease in their infants.

METHODS

This study randomised 95 pregnant women at risk of having an allergic infant, to daily supplements of 2.6 g omega-3 LCPUFA or a placebo of 2.7 g soya bean oil from gestational week 25 until 3 months of lactation. Breast milk samples were collected as colostrum, at one and 3 months. Milk fatty acids were related to allergic outcome in the infants at 24 months.

RESULTS

Omega-3 milk fatty acids were higher in women who received omega-3 supplements than the placebo group (p < 0.01). Higher proportions of milk eicosapentaenoic acid and docosahexaenoic acid and a lower arachidonic/eicosapentaenoic acid ratio were associated with an absence of IgE-associated disease in the infants. None of the children developed IgE-associated atopic eczema above a level of 0.83 mol% eicosapentaenoic acid in colostrum. [Correction added on 7 July 2016, after online publication: In the preceding sentence, the correct word should be "above" instead of "below" and this has been amended in this current version.] CONCLUSION: High omega-3 LCPUFA milk levels in mothers who received omega-3 LCPUFA supplements were related to fewer allergies in their children.

Breastmilk fatty acids in relation to sensitization - the ALADDIN birth cohort

BACKGROUND

Breastmilk fatty acids (FAs) have been associated with childhood allergic disease. Children of families with an anthroposophic lifestyle have a low prevalence of sensitization compared to reference groups. This study aimed to investigate whether the lower prevalence of sensitization among these children can be explained by the differences in breastmilk FA composition.

METHODS

The prospective birth cohort ALADDIN included 330 children from anthroposophic, partly anthroposophic and nonanthroposophic families recruited between 2004 and 2007 in Sweden. In total, 245 breastmilk samples, collected at 2 months of age, were analysed for FA composition. Allergen-specific IgE levels against seven common allergens were measured in the blood samples at the ages of 6, 12 and 24 months. Data were analysed longitudinally using generalized estimating equations.

RESULTS

An inverse association was observed between total concentration of omega-3 PUFA in breastmilk and sensitization in the child up to 24 months of age (highest vs lowest quartile, RRadj 0. 49, 95% CI 0.23-1.05, P for trend 0.024). No associations were observed between omega-6 PUFAs or ruminant FAs and sensitization. Overall, we observed 56% lower risks of sensitization among the anthroposophic group compared to the nonanthroposophic group (RRadj 0.44, 95% CI 0.21-0.90). This association remained largely unchanged when breastmilk omega-3 PUFA was included in the model.

CONCLUSION

Our results indicate that a higher concentration of omega-3 PUFAs in breastmilk may be associated with a reduced risk of sensitization up to 24 months of age; however, this did not explain the lower risk of sensitization among children of anthroposophic families.

Breast milk and its impact on maturation of the neonatal immune system

PURPOSE OF REVIEW

This article aims to review the evidence that breast milk can actively shape neonate gut immune system development toward a mature immune system capable of responding appropriately to encountered antigens.

RECENT FINDINGS

Recent findings in the adult have demonstrated the critical role of the interaction between diet, gut microbiota, gut epithelial cells and gut-associated lymphoid tissue in the development of immune responses. Here, we will review what is known in this field in the neonate, compare these data to those obtained in the adult and review how milk factors impact gut immune function in the short and long term.

SUMMARY

We propose that the neonate immune system and maternal milk represent an entity necessary to ensure not only appropriate function in early life but also long term immune homeostasis.

Omega-3 long-chain PUFA intake during pregnancy and allergic disease outcomes in the offspring: a systematic review and meta-analysis of observational studies and randomized controlled trials

BACKGROUND

There is some evidence that increased maternal intake of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy may reduce the incidence of immunoglobulin E (IgE)-mediated allergic disease.

OBJECTIVE

We aimed to evaluate prenatal n-3 LC-PUFA dietary exposure in observational studies and n-3 LC-PUFA supplementation in randomized controlled trials (RCTs) on outcomes of IgE-mediated allergic disease.

DESIGN

We conducted searches of the Cochrane Central Register of Controlled Trials, PubMed, Ovid MEDLINE, EMBASE, CINAHL, SCOPUS, and Web of Science to 30 July 2015. We included prospective cohort studies that showed an association between maternal fish or n-3 LC-PUFA intake during pregnancy and RCTs with a prenatal intervention to modify maternal n-3 LC-PUFA intake and outcomes of allergic disease (eczema, rhino-conjunctivitis, asthma) or sensitization in the offspring.

RESULTS

A total of 13 publications from 10 prospective cohort studies and 7 publications representing 5 unique RCTs were included. Three RCTs were combined in a meta-analysis for selected outcomes. Nine of 13 observational study publications and 5 of 7 publications from RCTs found a protective association between increased prenatal n-3 LC-PUFA or fish intake and incidence of allergic disease symptoms in the child. Meta-analysis was limited because of the heterogeneity of the RCTs. Pooled results showed a significant reduction in the incidence of "atopic eczema," "any positive SPT [skin-prick test]," "sensitization to egg," and "sensitization to any food" in the first 12 mo of life [RRs (95% CIs): 0.53 (0.35, 0.81), P = 0.004; 0.68 (0.52-0.89), P = 0.006; 0.55 (0.39-0.76), P = 0.0004; and 0.59 (0.46, 0.76), P < 0.0001, respectively].

CONCLUSIONS

Our systematic review and meta-analysis was suggestive of benefits of increased n-3 LC-PUFAs in the maternal diet and outcomes of childhood allergic disease. However, due to the inconsistency in results, the hypothesis linking maternal n-3 LC-PUFA intake to childhood allergic disease cannot unequivocally be confirmed or rejected.

Role of primary and secondary prevention in atopic dermatitis

Atopic dermatitis (AD) is a serious epidemiological problem in industrialized countries. The incidence of AD has increased considerably over the last 30 years. Atopic dermatitis is a chronic, recurrent, inflammatory skin disease accompanied by strong itching. It is characterized by typical features depending on age. The parents of children suffering from AD must be prepared to change their lifestyle. They should avoid factors which can promote skin lesions and apply appropriate, regular skin care. The article describes primary prevention of AD as well as prophylactic measures to avoid skin eczema. It presents the role of infections, vaccinations, breastfeeding and the influence of domestic animals, house renovation and moulds on development of AD. The article also describes the significance of the epidermal barrier, skin colonization by microbial agents, pruritus, stress, food and inhalant allergy among people who suffer from AD.

Breast milk fatty acid composition has a long-term effect on the risk of asthma, eczema, and sensitization

BACKGROUND

Levels of n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs in breast milk are associated with the development of allergic diseases up to school age. However, it is unknown whether this relationship persists when the child becomes older. We therefore studied the association between levels of n-3 PUFAs and n-6 PUFAs in breast milk of allergic- and nonallergic mothers and asthma, eczema and sensitization up to the age of 14 years.

METHODS

The study was nested in the ongoing PIAMA birth cohort. At the child's age of 3 months, 276 mothers provided a breast milk sample. Asthma (N total = 269) and eczema (N total = 274) were self-reported up to the child's age of 14 years. Specific serum IgE levels were measured at the ages of 4, 8 and 12 years (N total = 216). Generalized estimating equations analyses were used to take account of repeated observations.

RESULTS

Asthma up to the age of 14 years is less prevalent in children of allergic mothers receiving breast milk with higher levels of n-3 long chain polyunsaturated (LCP) fatty acids (OR 0.50; 95% CI 0.31-0.79), and more prevalent in children of nonallergic mothers receiving breast milk with higher levels of n-6LCP (OR 1.86; 95% CI 1.14-3.03). Weaker associations in similar direction were observed for eczema and sensitization. Direction of associations were consistent and of similar magnitude throughout childhood.

CONCLUSION

The association between breast milk fatty acid composition and asthma, eczema and sensitization persists up to the age of 14 years in children of both allergic and nonallergic mothers.

High levels of anti-inflammatory and pro-resolving lipid mediators lipoxins and resolvins and declining docosahexaenoic acid levels in human milk during the first month of lactation

Background

The fatty acid mixture of human milk is ideal for the newborn but little is known about its composition in the first few weeks of lactation. Of special interest are the levels of long-chain PUFAs (LCPUFAs), since these are essential for the newborn’s development. Additionally, the LCPUFAs arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are precursors for lipid mediators which regulate inflammation.

Methods

We determined the composition of 94 human milk samples from 30 mothers over the first month of lactation for fatty acids using GC-MS and quantified lipid mediators using HPLC-MS/MS.

Results

Over the four weeks period, DHA levels decreased, while levels of γC18:3 and αC18:3 steadily increased. Intriguingly, we found high concentrations of lipid mediators and their hydroxy fatty acid precursors in human milk, including pro-inflammatory leukotriene B4 (LTB4) and anti-inflammatory and pro-resolving lipoxin A4 (LXA4), resolvin D1 (RvD1) and resolvin E1 (RvE1). Lipid mediator levels were stable with the exception of two direct precursors.

Conclusions

Elevated levels of DHA right after birth might represent higher requirements of the newborn and the high content of anti-inflammatory and pro-resolving lipid mediators and their precursors may indicate their role in neonatal immunity and may be one of the reasons for the advantage of human milk over infant formula.

n-3 Long-chain PUFA reduce allergy-related mediator release by human mast cells in vitro via inhibition of reactive oxygen species

Increased n-6 and reduced n-3 long-chain PUFA (LC-PUFA) intake in Western diets may contribute to the increased prevalence of allergic diseases. Key effector cells in allergy are mast cells (MC). The aim of the present study was to investigate the effects of n-6 v. n-3 LC-PUFA on MC phenotype. Human MC lines (LAD2 and HMC-1) were incubated for 24 h with either arachidonic acid (AA, n-6 LC-PUFA) or the n-3 LC-PUFA EPA or DHA. The effects of these three LC-PUFA on degranulation, mediator secretion and reactive oxygen species (ROS) generation were assessed. ROS, mitogen-activated protein kinase (MAPK) or NF-κB inhibitors were used to unravel signalling pathways involved in cytokine secretion. AA, EPA or DHA did not reduce IgE-mediated degranulation by LAD2 cells. However, AA increased PGD₂ and TNF-α secretion by ionomycin/phorbol 12-myristate 13-acetate-stimulated HMC-1, whereas EPA and DHA more prominently inhibited IL-4 and IL-13 secretion. Suppression of IL-4 and IL-13 release by LC-PUFA correlated with reduced ROS generation. IL-4 and IL-13 release by activated HMC-1 was abrogated using ROS inhibitors. Inhibition of MAPK signalling, but not NF-κB, downstream of ROS reduced IL-13 secretion by activated HMC-1. Combined incubation of EPA or DHA with MAPK inhibitors further suppressed IL-13 secretion. In conclusion, the n-6 LC-PUFA AA enhanced pro-inflammatory mediator production by MC, while the n-3 LC-PUFA EPA as well as DHA more effectively suppressed ROS generation and IL-4 and IL-13 release. This suggests that dietary supplementation with EPA and/or DHA may alter the MC phenotype, contributing to a reduced susceptibility to develop and sustain allergic disease.

ABM Clinical Protocol #24: Allergic Proctocolitis in the Exclusively Breastfed Infant

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient. These guidelines are not intended to be all-inclusive, but to provide a basic framework for physician education regarding breastfeeding.

High-dose docosahexaenoic acid supplementation of preterm infants: respiratory and allergy outcomes

BACKGROUND

Docosahexaenoic acid (DHA) has been associated with downregulation of inflammatory responses.

OBJECTIVE

To report the effect of DHA supplementation on long-term atopic and respiratory outcomes in preterm infants.

METHODS

This study is a multicenter, randomized controlled trial comparing the outcomes for preterm infants <33 weeks' gestation who consumed expressed breast milk from mothers taking either tuna oil (high-DHA diet) or soy oil (standard-DHA) capsules. Data collected included incidence of bronchopulmonary dysplasia (BPD) and parental reporting of atopic conditions over the first 18 months of life.

RESULTS

Six hundred fifty-seven infants were enrolled (322 to high-DHA diet, 335 to standard), and 93.5% completed the 18-month follow-up. There was a reduction in BPD in boys (relative risk [RR]: 0.67 [95% confidence interval (CI): 0.47-0.96]; P=.03) and in all infants with a birth weight of <1250 g (RR: 0.75 [95% CI: 0.57-0.98]; P=.04). There was no effect on duration of respiratory support, admission length, or home oxygen requirement. There was a reduction in reported hay fever in all infants in the high-DHA group at either 12 or 18 months (RR: 0.41 [95% CI: 0.18-0.91]; P=.03) and at either 12 or 18 months in boys (RR: 0.15 [0.03-0.64]; P=.01). There was no effect on asthma, eczema, or food allergy.

CONCLUSIONS

DHA supplementation for infants of <33 weeks' gestation reduced the incidence of BPD in boys and in all infants with a birth weight of <1250 g and reduced the incidence of reported hay fever in boys at either 12 or 18 months.

The effects of omega-3 fatty acid supplementation in pregnancy on maternal eicosanoid, cytokine, and chemokine secretion

The incidence of allergic diseases has increased, and a relation between allergy and dietary fatty acids has been proposed. Modulation of the maternal immune function during pregnancy may have an impact on future clinical outcomes in the child. The aim of this study was to determine the effects of omega (omega)-3 long-chain polyunsaturated fatty acids (LCPUFA) supplementation during pregnancy on the plasma fatty acid composition in relation to the maternal immune function. Pregnant women with allergic disease in their immediate family were supplemented daily with 2.7 g omega-3 LCPUFA (n = 70) or 2.8 g soybean oil as placebo (n = 75) from the 25th gestational week. The proportions of eicosapentaenoic acid and docosahexaenoic acid in plasma/serum phospholipids increased in the omega-3-supplemented group, whereas arachidonic acid decreased during intervention. Lipopolysaccharide-induced prostaglandin E2 secretion from whole blood culture supernatants (n = 59) decreased in a majority of the omega-3-supplemented mothers (18 of 28, p = 0.002). The decreased prostaglandin E2 production was more pronounced among nonatopic than atopic mothers. The lipopolysaccharide-induced cytokine and chemokine secretion was not affected. Our results indicate that omega-3 LCPUFA supplementation during the last trimester may dampen certain immune responses involved in allergic inflammation.

Fish Oil Supplementation in Pregnancy Lowers F2-isoprostanes in Neonates at High Risk of Atopy

The anti-inflammatory properties of n-3 polyunsaturated fatty acids (n-3 PUFA) have suggested a potential role of these nutrients in dietary modification for prevention of allergic disease in early life. As oxidative stress is known to modify antigen presenting cell (APC) signalling and resulting immune responses, we examined the effects of maternal n-3 PUFA supplementation in pregnancy on markers of oxidative stress and APC function in neonates at high risk of allergy. Eighty-three pregnant atopic women were randomised to receive 4 g daily of either fish oil (n = 40) or olive oil (n = 43) capsules in a controlled trial from 20 weeks gestation until delivery. Plasma (cord blood) and urinary F2-isoprostanes were measured as markers of lipid peroxidation. Cord erythrocyte fatty acids and markers of APC function (HLA-DR expression and cytokine responses) were measured and related to levels of plasma F2-isoprostanes. Maternal fish oil supplementation lowered plasma (p < 0.0001) and urinary (p = 0.06) F2-isoprostanes. HLA-DR expression on APC was not different between the groups. In multiple regression analysis, 28.8% of the variance in plasma F2-isoprostanes was explained by positive relationships with erythrocyte arachidonic acid (AA) and monocyte HLA-DR expression and a negative relationship with erythrocyte eicosapentaenoic acid (EPA). This study shows that maternal supplementation with fish oil can attenuate neonatal lipid peroxidation. Clinical follow-up of these infants will help to determine if there are sustained effects on postnatal oxidative stress and expression of allergic disease.

Exclusive breastfeeding and incident atopic dermatitis in childhood: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND

Breastfeeding is undisputedly preferable to formula feeding for infant nutrition because of its nutritional, immunological and psychological benefits. However, studies on the association between breastfeeding and development of atopic dermatitis (AD) have shown inconsistent results.

OBJECTIVES

To examine the association between exclusive breastfeeding for at least 3 months after birth and the development of AD in childhood.

METHODS

An electronic literature search of MEDLINE (January 1966-May 2008) and EMBASE (1980-May 2008) was conducted. Prospective cohort studies that met the predetermined criteria were independently assessed by three reviewers. The pooled effect estimate was calculated by random effects model. Heterogeneity across the studies was investigated by meta-regression analysis.

RESULTS

Twenty-one studies with 27 study populations were included for meta-analysis. The summary odds ratio (OR) for the effect of exclusive breastfeeding on the risk of AD was 0.89 (95% confidence interval, CI 0.76-1.04). Heterogeneity was found across the studies (chi(2) = 83.6, d.f. = 26; P < 0.001). Breastfeeding was associated with a decreased risk of AD (OR 0.70; 95% CI 0.50-0.99) when analysis was restricted to the studies comparing breastfeeding with conventional formula feeding. The pooled OR for study populations with atopic heredity was 0.78 (95% CI 0.58-1.05).

CONCLUSIONS

There is no strong evidence of a protective effect of exclusive breastfeeding for at least 3 months against AD, even among children with a positive family history.

Long-chain polyunsaturated fatty acids influence the immune system of infants

Several events occur during the first months of life that allow the immune system to become competent and functional. The aim of this article is to review the rationale and evidence of an influence of (n-3) long-chain PUFA (LCPUFA) on the immune system of infants. The (n-3) LCPUFA exert their immunomodulatory activities at different levels. The (n-3) LCPUFA metabolites induce eicosanoid production, alter gene expression, and modify lipid raft composition, altering T-cell signaling; all contribute to immunological functional changes. However, the roles of these mechanisms and the types of T or other immunological cells involved remain unclear at present. Moreover, the effect of (n-3) LCPUFA on the immune system of infants may vary according to dose, time of exposure, and profile of the immune system (T-helper, Th1/Th2). Most of the interventional studies in infancy have been performed for the prevention of allergy. They all confirmed influence on T-cell function and cytokine profiles, but clinically beneficial effects are more conflicting. Supplementation of the maternal diet in pregnancy or early childhood with (n-3) LCPUFA is potentially a noninvasive intervention strategy to prevent the development of allergy, infection, and possibly other immune-mediated diseases. However, any long-term in vivo effects on (n-3) LCPUFA early in life for immunomodulatory defense in infants and later on immune status and health remain to be assessed.

Impact of PUFA on early immune and fetal development

It has recently been reported that the increased prevalence in childhood allergy may be linked to deviations in fetal immune development. One reason may be impaired nutrient supply. Hence, a well-differentiated placenta together with an optimal fetal nutrition via the mother are important prerequisites for the establishment of a functional immune system with normal immune responses. Fatty acids and their derivatives can influence both the early immune development and immune maturation by regulating numerous metabolic processes and the gene expression of important proteins such as enzymes and cytokines. The present review summarises the impact of nutritional fatty acids on the development of the immune system as well as the fetal development. It describes the mechanisms of action of PUFA, trans fatty acids and conjugated linoleic acids in programming the fetus with regard to its risk of acquiring atopic diseases in childhood.

Serum cholesterol level in infancy is inversely associated with subsequent allergy in children and adolescents. A 20-year follow-up study

BACKGROUND

Previous studies suggest an association between an altered lipoprotein profile and atopy. The association has been hypothesized to be due to alterations in the dietary fat intake, a factor possibly contributing to the increase of allergic diseases in industrialized countries.

OBJECTIVE

We aimed at assessing whether there is an association between the serum lipid levels in infancy and subsequent development of allergic symptoms in childhood and adolescence.

METHODS

A cohort of 200 unselected newborns was prospectively followed up from birth to age 20 years (from 1981 to 2002) with repeated measurements of total cholesterol from birth and throughout the first year of life. The subjects were re-examined at the ages of 5, 11 and 20 years, with assessment of the occurrence of allergic symptoms, skin prick testing (SPT) and measurement of total IgE and of the total, high- and low-density lipoprotein cholesterol.

RESULTS

Children and adolescents with allergic symptoms, SPT positivity and an elevated IgE had lower total cholesterol levels in infancy and childhood than the non-atopic subjects. The difference was not detectable in cord blood, but became significant from age 2 months onward.

CONCLUSION

The inverse association between the cholesterol level in infancy and subsequent manifestations of atopy seems not to be due to atopy-related dietary alterations, because it was already present in early infancy, when virtually all the infants were on a similar diet, i.e. on exclusive breastfeeding.

Breast-feeding duration and infant atopic manifestations, by maternal allergic status, in the first 2 years of life (KOALA study)

OBJECTIVE

To investigate the potential effect of modification by maternal allergic status on the relationship between breast-feeding duration and infant atopic manifestations in the first 2 years of life.

STUDY DESIGN

Data from 2705 infants of the KOALA Birth Cohort Study (The Netherlands) were analyzed. The data were collected by repeated questionnaires at 34 weeks of gestation and 3, 7, 12, and 24 months postpartum. Total and specific immunoglobulin E measurements were performed on venous blood samples collected during home visits at age 2 years. Relationships were analyzed using logistic regression analyses.

RESULTS

Longer duration of breast-feeding was associated with a lower risk for eczema in infants of mothers without allergy or asthma (P(trend) = .01) and slightly lower risk in those of mothers with allergy but no asthma (P(trend) = .14). There was no such association for asthmatic mothers (P(trend) = .87). Longer breast-feeding duration decreased the risk of recurrent wheeze independent of maternal allergy (P(trend) = .02) or asthma status (P(trend) = .06).

CONCLUSIONS

Our findings show that the relationship between breast-feeding and infant eczema in the first 2 years of life is modified by maternal allergic status. The protective effect of breast-feeding on recurrent wheeze may be associated with protection against respiratory infections.

Polyunsaturated fatty acids regulate cytokine and prostaglandin E2 production by respiratory cells in response to mast cell mediators

A protective association between breastfeeding and the development of bronchial asthma has been demonstrated. However, a mechanism remains unclear. FA present in human milk but rare in infant formula have been associated with marked immunological modulation as well as some indications of protection from asthma development. We examined the effect of in vitro manipulation of membrane phospholipid on the production of cytokines and prostaglandin (PG)E2 by respiratory epithelial cells (A549) in response to stimulation by mast cell mediators of allergic disease [histamine, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4 and IL-5]. DHA and CLA significantly decreased the production of IL-8 in response to stimulation by TNF-alpha [2907 +/- 970 (DHA) and 6471 +/- 1203 (CLA) vs. 12,287 +/- 2309 (control) pg/mL; P < or = 0.05, mean +/- SEM], whereas both EPA and DHA reduced histamine-stimulated RANTES (regulation on activation, T cell-expressed and -secreted) production [2314 +/- 861 (EPA) and 877 +/- 326 (DHA) vs. 8526 +/- 1118 (control) pg/mL; P < or = 0.03]. PGE2 released in response to histamine was decreased by n-3 [1305 +/- 399 (alpha-linolenic acid), 406 +/- 73 (EPA), and 265 +/- 32 (DHA) vs. 9324 +/- 3672 (control) pg/mL; P < or = 0.05] and increased by n-6 [18,843 +/- 4439 (arachidonic acid) vs. 9324 +/- 3672 (control) pg/mL; P = 0.02], with CLA producing a decrease of the same magnitude as DHA [553 +/- 126 (CLA) vs. 9324 +/- 3672 (control) pg/mL; P = 0.03]. This study demonstrates the potential for immunological manipulation of the respiratory epithelium by FA in situ during allergic responses and suggests that further investigation into FA intervention in infants via human milk or supplemented infant formula, to prevent the development of allergic disease, may be worthwhile.

Benefits and risks of breastfeeding

In the absence of significant, unpreventable risks, breastfeeding should be the norm for the nourishment of human infants and should, therefore, be encouraged for populations in all countries. Continued efforts of international and national agencies and healthcare professionals to aid and abet breastfeeding, reduce the risks that occur in some women during breastfeeding, provide the safest substitutes for human milk when that is necessary, and encourage further research into the posed questions should considerably improve the health of many children.

Fatty acid composition of human milk in atopic Danish mothers

BACKGROUND

Atopic dermatitis has been related to a disturbed metabolism of polyunsaturated fatty acids (PUFAs).

OBJECTIVE

We tested whether the PUFA composition of breast milk differs significantly between mothers with atopic dermatitis, mothers with other types of atopy, and nonatopic mothers. We also investigated whether differences in diet can explain possible observed differences.

DESIGN

Mothers with current or previous asthma (n = 396) were divided into 3 groups according to history of atopic dermatitis and allergic rhinitis. Breast-milk samples were collected from 314 women approximately 3 wk after delivery. The habitual diet of the women was assessed with food-frequency questionnaires in the 25th week of gestation (n = 207). Breast-milk samples and simultaneous dietary data from 14 nonatopic mothers were used for comparison.

RESULTS

Compared with the milk of nonatopic mothers, that of atopic mothers had significantly higher concentrations of 22:5n-6 and lower concentrations of 20:5n-3; moreover, 20:4n-6/20:5n-3, 22:5n-6/22:6n-3, and long-chain n-3 PUFA/18:3n-3 were shifted toward n-6 PUFA and 18:3n-3 in nonatopic and atopic mothers, respectively. No differences in breast-milk PUFA composition were evident between the subject groups. The diets of the groups differed only slightly with respect to protein intake. However, the PUFA composition of the breast milk was associated with diet and time of milk sampling, and the above difference in milk PUFAs disappeared when those factors were taken into account.

CONCLUSION

Our data do not support the possibility that the fatty acid composition of breast milk is affected by atopic dermatitis or atopy in general, because most differences in breast-milk PUFA composition appear to be explained by the diet.

Breast milk fatty acids may link innate and adaptive immune regulation: analysis of soluble CD14, prostaglandin E2, and fatty acids

In addition to its role in sensing intraluminal microbial antigens, soluble (s)CD14 may regulate immune responses by its lesser known function as a lipid carrier with possible influences in the production of fatty acid-derived eicosanoids. We investigated the interrelations of fatty acids, prostaglandin E2 (PGE2), and sCD14 and their role in infant atopic eczema during the first year of life. Serum and breast milk samples from mothers and serum samples from their infants were collected at infant's age 3 mo and analyzed for sCD14 and PGE2 concentrations and for fatty acid compositions. The main correlation of sCD14 was with arachidonic acid (20:4n-6) (AA). Dihomo-gamma-linolenic acid (20:3n-6) (DHGLA) and the ratio of n-6 to n-3 fatty acids correlated positively and docosahexaenoic acid (22:6n-3) (DHA) and sum of n-3 fatty acid negatively with PGE2 in mother's serum and linoleic acid (LA) negatively with PGE2 in breast milk. Soluble CD14 tended to be higher and LA, total polyunsaturated fatty acid (PUFA), and sum of n-6 fatty acids were lower in breast milk received by infants with atopic eczema compared with those without. These results suggest that fatty acids contribute to the regulation of innate and adaptive immune responses and link intraluminal exposures, mother's diet, and microbes.

Breast milk fatty acids and allergic disease in preschool children: the Prevention and Incidence of Asthma and Mite Allergy birth cohort study

BACKGROUND

Better understanding of the association between early life lipid intakes and the development of allergic diseases is needed.

OBJECTIVE

We prospectively studied breast milk content of n-6, n-3, and trans fatty acids in relation to allergic symptoms at the ages of 1 and 4 years.

METHODS

Fatty acid content was determined in breast milk samples of 265 (158 allergic and 107 nonallergic) mothers of children participating in the Prevention and Incidence of Asthma and Mite Allergy study. Outcome variables studied were parental reported eczema at age 1 year, eczema at age 4 years, asthma at age 4 years, and, in a subgroup of 133 children, sensitization at age 4 years.

RESULTS

In children of mothers with allergy, breast milk n-3 long chain polyunsaturated fatty acids and the ratio between n-3 and n-6 long chain polyunsaturated fatty acids were inversely associated with asthma and with persistent symptoms (eczema at age 1 year and eczema at age 4 years and/or asthma at age 4 years), but no associations between breast milk fatty acids and sensitization were observed. In children of mothers with allergy, also trans fatty acids tended to be inversely associated with allergic symptoms. In children of mothers without allergy, no associations between breast milk fatty acids and allergic symptoms were observed, but alpha-linolenic acid (18:3n-3) was positively associated with sensitization.

CONCLUSION

In susceptible infants, the risk to develop allergic symptoms, but not the risk of sensitization, was modified by intake of n-3 long chain polyunsaturated fatty acids through breast milk.

Impact of early dietary gamma-linolenic acid supplementation on atopic eczema in infancy

Polyunsaturated fatty acids (PUFAs) are components of cell membranes and may play an immunomodulating role in the pathogenesis of atopic dermatitis (AD). The goal was to determine the impact of PUFAs on AD by dietary supplementation of infants. Based on the parents' decision on their babies' primary feeding, mothers and newborns were randomized to the supplementation with gamma-linolenic acid (GLA) or placebo for up to 6 months. Breastfed infants received GLA by supplementing their mothers. Formula diet was commercial whey hydrolysate unsupplemented with PUFAs. Of 131 eligible infants, 24 developed AD within the first year of life. Of these, nine belonged to the exclusively breastfed group (n = 58), 14 to the combined-fed group (n = 53), and one to the never breastfed group (n = 20). We could not find an influence of GLA on the development of AD. In subjects with AD, at 1 yr of age the serum-immunoglobulin E (IgE) was the lowest in the GLA-supplemented group A-subjects. In the GLA-supplemented group, GLA-levels in breast milk were similar in atopic and non-atopic infants. In the non-supplemented group the GLA-content of breast milk was 0.07% of total fatty acids in atopic infants vs. 0.17% in non-atopic infants (p < 0.01). Dietary GLA-supplementation could not prevent AD. Interestingly, the number of infants developing AD was the lowest in never breastfed children. In infants suffering from AD, GLA-supplementation seemed to reduce total IgE in the first year of life.

Atopy, eczema and breast milk fatty acids in a high-risk cohort of children followed from birth to 5 yr

BACKGROUND

The incidence of atopic diseases such as eczema is increasing in westernized societies. The suggestion that there is a "protective" association between the unique fatty acid composition of breast milk, particularly the omega-3 (n-3) and omega-6 (n-6) essential polyunsaturated fatty acid content, and the development of atopic disease in children was investigated in a cohort study of 263 infants born into families with a history of allergy (one or both parents had asthma, hayfever, eczema). The objectives of this study were to determine the lipid profile [specifically in relation to long-chain polyunsaturated fatty acid (LC-PUFA) composition] in maternal breast milk samples collected at 6 wk and at 6 months following birth, and to investigate the potential role of these fatty acids in modulating the phenotype of children at high genetic risk of developing atopic disease.

METHOD

Breast milk samples were available from 91 atopic mothers at their child's ages of 6 wk and 6 months. These samples were analysed for the fatty acid spectrum. Analysis of variance was used to detect differences between groups of outcomes (no atopy or eczema, non-atopic eczema, atopy, atopic eczema) at ages 6 months and 5 yr, and a multiple comparisons procedure was conducted to isolate the parameters producing the different results (F-test, LSD test). For the exposure variables, n-3 and n-6 fatty acids are expressed as weight percentage and as a ratio (at both time-points).

RESULTS

The fatty acid profiles of maternal breast milk at 6 wk and 6 months were similar. An increased ratio of n-6: n-3 fatty acids in both 6 wk and 6 month milk samples was associated with non-atopic eczema (p < 0.005) but not atopy alone or atopic eczema.

CONCLUSION

We found milk fatty acids were a significant modulator of non-atopic eczema but not atopy or atopic eczema in infants at 6 months. In mothers with a history of asthma, hayfever or eczema, their 6-month-old infants were more likely to develop non-atopic eczema if their milk had a higher ratio of n-6: n-3 LC-PUFA.

Fish oil supplementation of lactating mothers affects cytokine production in 2 1/2-year-old children

n-3 PUFA influence immune functioning and may affect the cytokine phenotype during development. To examine whether maternal fish oil supplementation during lactation could modify later immune responses in children, 122 lactating Danish mothers with a fish intake below the population median were randomized to groups supplemented for the first 4 mon of lactation with 4.5 g/d of fish oil (equivalent to 1.5 g/d of n-3 long-chain PUFA) or olive oil. Fifty-three mothers with a fish intake in the highest quartile of the population were also included. The FA composition of erythrocyte membranes was measured at 4 mon and at 2 1/2 yr. Plasma immunoglobulin E (IgE) levels and cytokine production in lipopolysaccharide-stimulated whole-blood cultures were determined at 2 1/2 yr. Erythrocyte n-3 PUFA at 4 mon were higher in infants from the fish oil group compared with the olive oil group (P < 0.001) but were no longer different at 2 1/2 yr. The median production of lipopolysaccharide-induced interferon gamma (IFN-gamma) in the fish oil group was fourfold higher than that in the olive oil group (P = 0.034), whereas interleukin-10 (IL-10) production was similar. The IFN-gamma/IL-10 ratio was twofold higher in the fish oil group (P = 0.019) and was positively correlated with 20:5n-3/20:4n-6 in erythrocytes at 4 mon (P = 0.050). The percentages of atopic children and plasma IgE were not different in the two groups, but the study was not designed to look at atopy. Cytokine responses and erythrocyte FA composition in children of mothers with a high fish intake were intermediate in comparison with those in the randomized groups. Fish oil supplementation during lactation resulted in increased in vitro IFN-gamma production in the children 2 yr after the supplementation was given, which may reflect a faster maturation of the immune system.

Allergic sensitisation and allergic rhinitis are associated with n-3 polyunsaturated fatty acids in the diet and in red blood cell membranes

OBJECTIVE

Due to inconsistent results based on dietary intake data, unsaturated fatty acids in red blood cell (RBC) membranes and diet were used to investigate their association with allergic sensitisation and allergic rhinitis.

DESIGN

Cross-sectional, population-based study.

SETTING

Bavarian Nutrition Survey II (2002-03), Germany.

SUBJECTS

A total of 568 adult participants, 325 women and 243 men.

METHODS

By means of logistic regression models, the relation of fatty acids to (i) allergic sensitisation as defined by means of specific serum immunoglobulin E analysis (CAPSX1 class > or = 2), and (ii) self-reported allergic rhinitis was examined.

RESULTS

A high cell membrane level of eicosapentaenoic acid (EPA, 20:5 n-3) was inversely associated with allergic sensitisation, the adjusted odds ratio (OR) and 95% confidence interval (95% CI) were 0.52 (0.30-0.90) for the highest (vs lowest) quartile. A similar effect was observed for allergic rhinitis with an OR (95% CI) of 0.50 (0.24-1.03; P = 0.027 for trend). A higher dietary intake of alpha-linolenic acid (ALA, 18:3 n-3) was associated with a decreased risk of allergic sensitisation and allergic rhinitis with ORs (95% CIs) of 0.51 (0.28-0.93) and 0.43 (0.20-0.93), respectively, in the highest quartiles. No other dietary or cell membrane unsaturated fatty acid was significantly associated with the outcome variables, nor was the n-6/n-3 ratio. The strongest effects were observed among subjects under the age of 40 y.

CONCLUSIONS

In this cross-sectional study among adults, a high content of n-3 fatty acids in RBC membranes (EPA) or in the diet (ALA) is associated with a decreased risk of allergic sensitisation and allergic rhinitis.

Fatty acids in early human milk after preterm and full-term delivery

BACKGROUND

It has been much debated whether fatty acid composition of human milk differs after preterm as compared to full-term delivery.

SUBJECTS AND METHODS

Human milk samples were obtained from mothers of preterm (n = 8, gestational age: 28.0 [4.2] weeks, birthweight: 1,235 [420] g, median [interquartile range]) and full-term (n = 10, gestational age: 38.5 [2.7] weeks, birthweight: 3375 [282] g) infants every day during the first week and thereafter on the 14th, 21st, and 28th day of lactation. Fatty acid composition was measured by high-resolution capillary gas-liquid chromatography.

RESULTS

Maternal age and body mass index did not differ, and food frequency questionnaire did not reveal significant differences in diet between the two groups. Fat contents of human milk did not differ between the two groups. Values of linoleic acid (C18:2n-6) and alpha-linolenic acid (C18:3n-3) did not differ throughout the study. Values of the metabolites C18:3n-6 and C20:3n-6 as well as C18:4n-3 and C20:3n-3 were significantly higher after preterm as compared with full-term delivery. Values of arachidonic acid (C20:4n-6; e.g., day 4: 0.82 [0.4] vs. 0.44 [0.28]; day 7: 0.61 [0.25] vs. 0.34 [0.25]; day 21: 0.33 [0.18] vs. 0.44 [0.44]; in weight percent, preterm versus full-term, P < 0.05) and docosahexaenoic acid (C22:6n-3; e.g., day 4: 0.33 [0.23] vs. 0.15 [0.14]; day 7: 0.26 [0.16] vs. 0.13 [0.15]; day 21: 0.11 [0.08] vs. 0.21 [0.17]; P < 0.05) were significantly higher in human milk samples of mothers of preterm as compared with full-term infants.

CONCLUSION

In this study, percentage contributions of arachidonic and docosahexaenoic acids as well as the those of the intermediary metabolites of essential fatty acid metabolism were all significantly higher in early human milk samples of mothers giving birth to very low birth weight preterm as compared with full-term infants.

Breast milk fatty acid composition is associated with development of atopic dermatitis in the infant

OBJECTIVE

Breast milk fatty acids may have immunomodulatory properties related to the development of atopic disease. The aim of this study was to assess the impact of the breast milk fatty acid composition on the development of atopic dermatitis (AD) in high-risk infants.

METHODS

Mothers with atopic disease were recruited at the end of gestation. Maternal food records and breast milk samples were collected at the infants' age of one month. Infants were clinically examined and AD diagnosed at one, three, six, and 12 months.

RESULTS

Altogether 13 of 34 (38%) infants were diagnosed with AD during the first year of life. Infants developing AD had consumed breast milk with a higher ratio of saturated to polyunsaturated fatty acids and less n-3 fatty acids compared to infants not developing AD. Specifically, breast milk consumed by infants with AD contained more stearic acid, 8.9% of total fatty acids (95% confidence interval 7.9-10.0) in comparison to those without AD, 7.1% (95% CI 6.6-7.7).

CONCLUSION

Breast milk rich in saturated and low in n-3 fatty acids may be a risk factor for atopic dermatitis in the infant.

Does fish oil supplementation in pregnancy reduce the risk of allergic disease in infants?

PURPOSE OF REVIEW

Parallel increases in many inflammatory diseases over the last 40 years suggest that common environmental changes are promoting inflammatory immune responses and/or inhibiting the processes that normally keep these in check. One key change during this period has been declining intakes of anti-inflammatory dietary factors, including omega-3 polyunsaturated fatty acids (n-3 PUFA). As allergic diseases often first manifest in early infancy, prevention strategies need to be targeted early, even in utero. This review will examine recent evidence for the use of fish oil during this early period as a primary prevention strategy for allergic disease.

RECENT FINDINGS

N-3 PUFA have well documented anti-inflammatory effects in vitro and have also been demonstrated to have health benefits in a range of chronic inflammatory diseases, including cardiovascular disease, rheumatoid arthritis and diabetes, supporting their role in modulating inflammation in vivo. Although the effects of fish oil supplementation in established allergic disease are less convincing, there is accumulating evidence that dietary n-3 PUFA may have greater effects before allergic responses are established.

SUMMARY

Supplementation of the maternal diet in pregnancy with n-3 PUFA may provide a non-invasive intervention with significant potential to prevent the development of allergic and possibly other immune-mediated diseases.

The ratio of n-6 to n-3 fatty acids in maternal diet influences the induction of neonatal immunological tolerance to ovalbumin

Prevalence of allergy is increasing in many countries and might be related to changed environmental factors, such as dietary fatty acids (FA). The present study investigates whether dietary ratio of n-6 to n-3 FA influences the induction of immunological tolerance to ovalbumin (OA) in neonatal rats. During late gestation and throughout lactation Sprague-Dawley rats were fed a diet containing 7% linseed oil (n-3 diet), sunflower oil (n-6 diet) or soybean oil (n-6/n-3 diet). At 10-16 days of age the rat offspring were subsequently exposed, or not, to OA via the milk. The offspring were weaned onto the same diets as the mothers and immunized with OA and the bystander antigen human serum albumin (HSA). In the offspring on the n-3 diet exposure to OA via the milk resulted in lower delayed type hypersensitivity reaction (DTH) and antibody responses against both OA and HSA, compared to those in the offspring not exposed to OA, indicating the induction of oral tolerance. In the offspring on the n-6 diet, the exposure to OA led to depressed specific immune responses against only OA, not HSA. In the offspring on the n-6/n-3 diet oral exposure to OA did not influence immune responses against OA, or HSA. The results indicate that the dietary ratio of n-6/n-3 FA is important for the induction of neonatal oral tolerance. Thus nonoptimal feeding may have effects on the development of immunological tolerance to dietary antigen ingested by the mother. The ratio of n-6/n-3 FA in the diet may be considered in the context of increased prevalence of allergy.

Changes of Fatty Acid Composition of Human Milk during the First Month of Lactation: A Day-to-Day Approach in the First Week

BACKGROUND

Fatty acid composition of human milk (HM) is known to change considerably during lactation. However, we were unable to find data on changes of fatty acid composition of HM during the very early phase of lactation, i.e. in the first week of life.

SUBJECTS AND METHODS

HM samples were obtained from 18 healthy lactating women every day during the first week and thereafter on the 14th and 28th days of lactation. Fatty acid composition of colostrum and mature HM samples was determined by high-resolution capillary gas-liquid chromatography.

RESULTS

Values of the n-6 essential fatty acid, linoleic acid, in HM did not change significantly during the first month of lactation, whereas values of the n-3 essential fatty acid, alpha-linolenic acid, showed significant increases during the first 2 weeks of lactation (1st day: 0.49 [0.12], % weight/weight, median [ranges from the 1st to the 3rd quartile], 14th day: 0.69 [0.31], p < 0.05). In contrast, values of the n-6 long-chain metabolites, eicosadienoic-, dihomo-gamma-linolenic- and arachidonic acid, as well as the values of the n-3 long-chain metabolites, eicosatrienoic-, and eicosapentaenoic acid exhibited significant decreases during the entire period investigated. The principal n-3 long-chain metabolite, docosahexaenoic acid, showed a significant increase between the 3rd and 14th days, but a significant decrease between the 14th and 28th days (3rd day: 0.15 [0.13], 14th day: 0.28 [0.11], p < 0.05, 28th day: 0.19 [0.12], p < 0.01). There were statistically significant positive correlations between arachidonic and docosahexaenoic acid values on the 1st (r = 0.67, p < 0.01), 5th (r = 0.56, p < 0.05) and the 6th (r = 0.53, p < 0.05) days of lactation.

CONCLUSION

Fatty acid composition of HM changes significantly even during the first week of lactation. The lack of positive correlation between essential fatty acids and their long-chain metabolites suggests that it is not only the availability of essential fatty acids that influences the fatty acid composition of human colostrum.

Dietary prevention of allergic diseases in infants and small children. Part III: Critical review of published peer-reviewed observational and interventional studies and final recommendations

The role of primary prevention of allergic diseases has been a matter of debate for the last 40 years. In order to shed some light on this issue, a group of experts of the Section of Pediatrics EAACI reviewed critically the existing literature on the subject. An analysis of published peer-reviewed observational and interventional studies was performed following the statements of evidence as defined by WHO. The results of the analysis indicate that breastfeeding is highly recommended for all infants irrespective of atopic heredity. A dietary regimen is unequivocally effective in the prevention of allergic diseases in high-risk children. In these patients breastfeeding combined with avoidance of solid food and cow's milk for at least 4-6 months is the most effective preventive regimen. In the absence of breast milk, formulas with documented reduced allergenicity for at least 4-6 months should be used.

Fatty acids in colostrum from mothers of children at high risk of atopy in relation to clinical and laboratory signs of allergy in the first year of life

BACKGROUND

It remains controversial whether fatty acid (FA) composition of breast milk relates to development of atopy in the infant. This study evaluates FA in colostrum from mothers of children at high risk of atopy in association with atopy at the age of 1 year.

METHODS

The FA of colostrum were analyzed for 218 children (60 with low birth weight between 1500 and 2500 g, 84 with a history of maternal atopy, and 74 with an elevated cord blood immunoglobulin (Ig)E of >0.9 IU/ml). Total lipids were extracted, methylated and separated by gas-liquid chromatography. Laboratory screening for allergic sensitization and clinical examination took place within the Leipzig Allergy Risk Children's Study (LARS).

RESULTS

Low birth weight was correlated with low percentage levels of 20:2n-6, 22:2n-6, and 22:3n-3 (r = 0.14, P < 0.05; r = 0.14, P < 0.05 and r = 0.20, P < 0.01, respectively) and low gestational age at birth was correlated with low 22:3n-3 (r = 0.15, P < 0.05). There was no association between FA and atopic eczema at the age of 1 year. However, high linoleic acid (LA, 18:2n-6) was linked to high specific IgE against cow's milk protein (P < 0.05), and low docosapentaenoic acid (DPA, 22:5n-3) was associated with elevated total serum IgE (P < 0.05) at the age of 1 year, respectively.

CONCLUSIONS

The polyunsaturated fatty acid composition of colostrum in a high risk newborn population shows associations with atopic sensitization at the age of 1 year and may be predictive for later atopic disease.

Fatty acids, the immune response, and autoimmunity: a question of n-6 essentiality and the balance between n-6 and n-3

The essentiality of n-6 polyunsaturated fatty acids (PUFA) is described in relation to a thymus/thymocyte accretion of arachidonic acid (20:4n-6, AA) in early development, and the high requirement of lymphoid and other cells of the immune system for AA and linoleic acid (1 8:2n-6, LA) for membrane phospholipids. Low n-6 PUFA intakes enhance whereas high intakes decrease certain immune functions. Evidence from in vitro and in vivo studies for a role of AA metabolites in immune cell development and functions shows that they can limit or regulate cellular immune reactions and can induce deviation toward a T helper (Th)2-like immune response. In contrast to the effects of the oxidative metabolites of AA, the longer-chain n-6 PUFA produced by gamma-linolenic acid (18:3n-6, GLA) feeding decreases the Th2 cytokine and immunoglobulin (Ig)G1 antibody response. The n-6 PUFA, GLA, dihomo-gamma-linolenic acid (20:3n-6, DHLA) and AA, and certain oxidative metabolites of AA can also induce T-regulatory cell activity, e.g., transforming growth factor (TGF)-beta-producing T cells; GLA feeding studies also demonstrate reduced proinflammatory interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha production. Low intakes of long-chain n-3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and Th2 responses, proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical role in long-chain n-3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n-3 PUFA from fish oils increase survival and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n-3 PUFA augment disease, whereas n-6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n-6 and n-3 families are clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert their clinical effects are not well understood. Finally, the view that all n-6 PUFA are proinflammatory requires revision, in part, and their essential regulatory and developmental role in the immune system warrants appreciation.

Breast milk fatty acids, eicosanoids, and cytokines in mothers with and without allergic disease

Allergic disease (AD), including atopic eczema, asthma, allergic rhinitis, and food allergy, is characterized by an imbalance between cytokines produced by distinct T-helper cell subtypes. Whether this imbalance can be transferred from mother to breast milk remains to be established. The objective was to investigate the concentrations and interactions of nutritional and inflammatory factors in breast milk. Breast milk samples were collected from mothers with AD (n = 43) and without AD (n = 51). The concentrations of transforming growth factor (TGF)-beta2, tumor necrosis factor-alpha, IL-4, IL-10, prostaglandin E2, and cysteinyl leukotrienes were measured by immunoassays and fatty acid composition by gas chromatography. Mothers with AD had a lower concentration of TGF-beta2 in breast milk [median (interquartile range), 420 (278-701) ng/L] compared with those without AD [539 (378-1108) ng/L; p = 0.003], whereas other cytokines, prostaglandin E2, and cysteinyl leukotriene concentrations or fatty acid composition were not significantly different between the groups. The breast milk inflammatory factors and fatty acid composition were shown to be related. A positive association was observed between TGF-beta2 and the proportion of polyunsaturated fatty acids (p = 0.038) and a negative association between TGF-beta2 and the proportion of saturated fatty acids (p = 0.029) in breast milk. The reduced TGF-beta2 concentration in the breast milk of mothers with AD may interfere with the development of the mucosal immune system of the breast-fed infant. The observed associations between nutritional and inflammatory factors in breast milk suggest that it may be possible to influence the immunologic properties of breast milk by dietary intervention of the mother.

Maternal fish oil supplementation in pregnancy reduces interleukin-13 levels in cord blood of infants at high risk of atopy

BACKGROUND AND OBJECTIVES

The epidemiological association between higher dietary n-3 polyunsaturated fatty acids (PUFA) and lower prevalence of asthma, has led to interest in the role of early dietary modification in allergic disease prevention. In this study we examined the effects of maternal n-3 (PUFA)-rich fish oil supplementation on cord blood (CB) IgE and cytokine levels in neonates at risk of developing allergic disease.

METHODS

In a randomized double-blind, placebo-controlled trial, 83 atopic pregnant women received either fish oil capsules (n = 40) containing 3.7 g n-3 PUFA/day or placebo capsules (n = 43) from 20 weeks gestation until delivery. CB cytokine levels (IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, TNF-alpha and IFN-gamma) and total IgE levels were measured and compared between the two groups. Fatty acid composition of red cell membranes was analysed by gas chromatography and the relationships among PUFA, cytokine and IgE levels were examined.

RESULTS

Maternal fish oil supplementation resulted in a significant increase in n-3 PUFA levels (P < 0.001) in neonatal erythrocyte membranes. Neonates whose mothers had fish oil supplementation had significantly lower plasma IL-13 (P < 0.05) compared to the control group. There was also a significant inverse relationship between levels of n-3 PUFA in neonatal cell membranes and plasma IL-13. There was no difference in levels of IgE and the other cytokines measured.

CONCLUSIONS

This study provides preliminary evidence that increasing neonatal n-3 PUFA levels with maternal dietary supplementation can achieve subtle modification of neonatal cytokine levels. Further assessment of immune function and clinical follow-up of these infants will help determine if there are any significant effects on postnatal immune development and expression of allergic disease.

N-3 polyunsaturated fatty acids and inflammation: from molecular biology to the clinic

The immune system is involved in host defense against infectious agents, tumor cells, and environmental insults. Inflammation is an important component of the early immunologic response. Inappropriate or dysfunctional immune responses underlie acute and chronic inflammatory diseases. The n-6 PUFA arachidonic acid (AA) is the precursor of prostaglandins, leukotrienes, and related compounds that have important roles in inflammation and in the regulation of immunity. Feeding fish oil results in partial replacement of AA in cell membranes by EPA. This leads to decreased production of AA-derived mediators, through several mechanisms, including decreased availability of AA, competition for cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, and decreased expression of COX-2 and 5-LOX. This alone is a potentially beneficial anti-inflammatory effect of n-3 FA. However, n-3 FA have a number of other effects that might occur downstream of altered eicosanoid production or might be independent of this effect. For example, dietary fish oil results in suppressed production of proinflammatory cytokines and can modulate adhesion molecule expression. These effects occur at the level of altered gene expression. Fish oil feeding has been shown to ameliorate the symptoms of some animal models of autoimmune disease and to protect against the effects of endotoxin. Clinical studies have reported that oral fish oil supplementation has beneficial effects in rheumatoid arthritis and among some asthmatics, supporting the idea that the n-3 FA in fish oil are anti-inflammatory. There are indications that the inclusion of fish oil in enteral and parenteral formulae is beneficial to patients.