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

Allergen shedding in human milk: Could it be key for immune system education and allergy prevention?

In addition to being a source of nutrients for the developing newborn, human milk contains thousands of bioactive compounds, which influence infant health in the short-term as exemplified by its major benefits on infectious disease prevention. Many of the human milk compounds also have the required characteristics to instruct immune development and guide long-term health. Prebiotics, probiotics, and varied antimicrobial molecules all have the potential to shape the composition and function of the establishing gut microbiota, which is known to be a major determinant of immune function. Another and less explored way human milk can instruct long-term immunity is through antigen shedding. Here, we will review the evidence that antigens from maternal environment and more specifically from allergen sources are found in human milk. We will discuss data from rodent models and birth cohorts showing that allergen shedding in breast milk may influence long-term allergy risk. We will uncover the variables that may underlie heterogeneity in oral tolerance induction and allergy prevention in children breast-fed by allergen-exposed mothers. We will focus on the parameters that control antigen transfer to breast milk, on the unique biological characteristics of allergens in breast milk, and on the milk bioactive compounds that were found to influence immune response in offspring. We propose this understanding is fundamental to guide maternal interventions leading to lifelong allergen tolerance.

The Gut‒Breast Axis: Programming Health for Life

The gut is a pivotal organ in health and disease. The events that take place in the gut during early life contribute to the programming, shaping and tuning of distant organs, having lifelong consequences. In this context, the maternal gut plays a quintessence in programming the mammary gland to face the nutritional, microbiological, immunological, and neuroendocrine requirements of the growing infant. Subsequently, human colostrum and milk provides the infant with an impressive array of nutrients and bioactive components, including microbes, immune cells, and stem cells. Therefore, the axis linking the maternal gut, the breast, and the infant gut seems crucial for a correct infant growth and development. The aim of this article is not to perform a systematic review of the human milk components but to provide an insight of their extremely complex interactions, which render human milk a unique functional food and explain why this biological fluid still truly remains as a scientific enigma.

Omega-3 polyunsaturated fatty acids promote angiogenesis in placenta derived mesenchymal stromal cells

Enhancement of angiogenesis is solicited in wound repair and regeneration. Mesenchymal stromal cells derived from the placenta (P-MSCs) have an inherent angiogenic potential. Polyunsaturated fatty acids (PUFAs) in turn, specifically the omega-3 (N-3) are essential for growth and development. They are also recommended as dietary supplements during pregnancy. We therefore hypothesized that addition of N-3 PUFAs in P-MSC culture media may enhance their angiogenic potential. Hence, we treated P-MSCs with omega-3 (N-3) fatty acids -Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) at different concentrations and tested their angiogenic potential. We saw an upregulation of both bFGF and VEGFA. We also found enhanced in vitro tube formation ability of P-MSCs treated with DHA: EPA. We then looked at the influence of the conditioned medium (CM) collected from P-MSCs exposed to DHA: EPA on the key effector cells -HUVECs (Human Umbilical Vein derived endothelial cells and their functionality was further confirmed on chick yolk sac membrane. We found that the CM of P-MSCs exposed to DHA: EPA could enhance angiogenesis in both cases. These result were finally validated in an in vivo matrigel plug assay which revealed enhanced migration and vessel formation in CM treated with DHA: EPA. Our data thus reveals for the first time that supplementation with lower concentration of PUFA enhances the angiogenic potential of P-MSCs making them suitable for chronic wound healing applications.

Is infant immunization by breastfeeding possible?

Breastfeeding is known as the most efficient way to prevent infectious disease in early life. Maternal anti-microbial immunoglobulins transfer through milk confers passive immunity to the breastfed child while his immune system is maturing. Maternal milk also contains bioactive factors that will stimulate this maturation. From the literature on breastfeeding prevention of immune-mediated disease and more specifically from our experiments conducted in the field of allergic disease prevention, we propose that breastfeeding may also induce antigen-specific immune responses in the breastfed child. We found that early oral antigen exposure through breast milk leads to tolerance or immune priming depending on the nature of the antigen transferred and accompanying maternal milk cofactors. Here, we will discuss our data in the light of prevention of infectious disease and will propose that possible milk transfer of microbial antigen could affect actively the immune response in breastfed children and thereby their long-term susceptibility to infectious disease. Further research in this direction may lead to novel strategies of early life vaccination, taking advantage of the possibility to stimulate antigen-specific immune responses through breast milk.

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.

Increased fat and polyunsaturated fatty acid content in sow gestation diet has no effect on gene expression in progeny during the first 7 days of life

The 'developmental origins of health and disease' hypothesis proposes not only that we are what we eat, but also that we could be what our parents ate. Here, we aimed to improve health and performance of young piglets via maternal diets based on the hypothesis that maternal nutritional interventions change metabolic programming in piglets, reflected by differential gene expression early in life. Therefore, sows were fed either a regular diet, based on barley, wheat and wheat by-products, sugar beet pulp, palm oil and oilseed meal, or a high-fat (HF) diet consisting of the regular diet supplemented with an additional amount of 3.5% soybean oil and 1% fish oil at the expense of palm oil and wheat. Performance results, physiological parameters and gene expression in liver of piglets and blood of piglets and sows at day 7 after farrowing from both diet groups were compared. The HF diet tended to enhance growth rate of the offspring in the first week of life. No significant differences in gene expression in liver tissue and blood could be detected between the two groups, neither with whole-genome microarray analysis, nor with gene specific qPCR analysis. In this study, the feeding of a high-fat diet with increased amounts of polyunsaturated fatty acid (PUFA) to gestating sows under practical farm settings did not induce significant changes in gene expression in sows and offspring.

The effect of dietary omega-3 polyunsaturated fatty acids on plasma lipids and lipoproteins of C57BL/6 mice is age and sex specific

There is clear evidence of the effects of sex and age on the prevalence of cardiovascular disease. We investigated the interactions of dietary omega (n)-3 polyunsaturated fatty acids (PUFA), sex, and age on plasma lipids and lipoproteins in the offspring of C57BL/6 mice exposed to high, medium, or low n-3 PUFA at weaning and 16 weeks postweaning. There was an increase in plasma triglycerides from weaning to 16 weeks in male and female offspring; however, the high n-3 PUFA group showed a reduction in triglycerides in both sexes at 16 weeks. High n-3 PUFA caused an increase in plasma LDL-cholesterol from weaning to 16 weeks in male offspring; however, the LDL particle size was significantly larger in the high n-3 PUFA group. Plasma from male mice showed higher cholesterol efflux compared to females; high n-3 PUFA increased cholesterol efflux. Thus the effects of n-3 PUFA are age and sex dependent.

Respiratory allergen from house dust mite is present in human milk and primes for allergic sensitization in a mouse model of asthma

There is an urgent need to identify environmental risk and protective factors in early life for the prevention of allergy. Our study demonstrates the presence of respiratory allergen from house dust mite, Der p 1, in human breast milk. Der p 1 in milk is immunoreactive, present in similar amounts as dietary egg antigen, and can be found in breast milk from diverse regions of the world. In a mouse model of asthma, oral exposure to Der p through breast milk strongly promotes sensitization rather than protect the progeny as we reported with egg antigen. These data highlight that antigen administration to the neonate through the oral route may contribute to child allergic sensitization and have important implications for the design of studies assessing early oral antigen exposure for allergic disease prevention. The up-to-now unknown worldwide presence of respiratory allergen in maternal milk allows new interpretation and design of environmental control epidemiological studies for allergic disease prevention.

Asthma and allergic diseases in pregnancy a review

Asthma and allergic disorders can affect the course and outcome of pregnancy. Pregnancy itself may also affect the course of asthma and related diseases. Optimal management of these disorders during pregnancy is vital to ensure the welfare of the mother and the baby.

Specific pharmacological agents for treatment of asthma or allergic diseases must be cautiously selected and are discussed here with respect to safety considerations in pregnancy. Although most drugs do not harm the fetus, this knowledge is incomplete. Any drug may carry a small risk that must be balanced against the benefits of keeping the mother and baby healthy. The goals and principles of management for acute and chronic asthma, rhinitis, and dermatologic disorders are the same during pregnancy as those for asthma in the general population.

Diagnosis of allergy during pregnancy should mainly consist of the patient's history and in vitro testing.

The assured and well-evaluated risk factors revealed for sensitization in mother and child are very limited, to date, and include alcohol consumption, exposure to tobacco smoke, maternal diet and diet of the newborn, drug usage, and insufficient exposure to environmental bacteria. Consequently, the recommendations for primary and secondary preventive measures are also very limited in number and verification.

Maternal farm exposure/ingestion of unpasteurized cow's milk and allergic disease

PURPOSE OF REVIEW

The prevalence of allergic diseases has reached a high prevalence in affluent countries. Yet, there are areas and living conditions associated with very low rates which are attributable to environmental exposures. One example is the low prevalence of childhood asthma and allergies amongst children raised on farms, particularly those exposed to farm animals and unprocessed cow's milk very early in life which are being reviewed in this article.

RECENT FINDINGS

Several studies have shown that maternal exposure to various farm animals in pregnancy is related to a reduced risk of atopic dermatitis in the child and immune responses which have generally been regarded as protecting from the development of asthma and allergies. In addition, maternal and infant consumption of unprocessed cow's milk has repeatedly been associated with protection from childhood asthma and allergies. The precise nature of the protective factors remains to be elucidated. Maternal exposures to farm animals result in increased microbial exposures, the diversity of which has been associated with protection from childhood asthma. The beneficial milk constituents may, however, not be contained in the microbial contamination of milk samples but rather in the whey fraction of unprocessed cow's milk.

SUMMARY

Better understanding of these protective exposures might in the future enable the development of new prevention strategies.

Dietary supplementation with omega-3-PUFA-rich fish oil reduces signs of food allergy in ovalbumin-sensitized mice

We investigated the effect of dietary supplementation with n-3 PUFA (fish oil source) in an experimental model of food allergy. Mice were sensitized (allergic group) or not (nonallergic group) with OVA and were fed with OVA diet to induce allergy signals. Mice were fed with regular diet in which 7% of lipid content was provided by soybean (5% of n-3 PUFA) or fish (25% of n-3 PUFA) oil. Allergic group mice had increased serum levels of antiovalbumin IgE and IgG1 and changes in small intestine, characterized by an increased edema, number of rolling leukocytes in microcirculation, eosinophil infiltration, mucus production, and Paneth cell degranulation, in comparison to non-allergic group. All these inflammatory parameters were reduced in mice fed high-n-3-PUFA diet. Our data together suggest that diet supplementation with n-3 PUFA from fish oil may consist of a valid adjuvant in food allergy treatment.

Maternal intake of fatty acids during pregnancy and allergies in the offspring

Fatty acids (FA) are known to have a number of immunological effects and, accordingly, may play a role in the development of allergic diseases. We investigated the effect of maternal intake of FA during pregnancy on the risk of allergic rhinitis, wheeze and atopic eczema in children aged 5 years. The present study analysed data from the Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study, a population-based birth cohort study with a 5-year follow-up. Complete information on maternal diet (assessed by a validated FFQ) and International Study of Asthma and Allergies in Childhood-based allergic outcomes was available for 2441 children. Cox proportional regression and logistic regression were used for the analyses. After adjusting for potential confounding variables, high maternal consumption of butter and butter spreads (hazard ratio (HR) 1.33; 95 % CI 1.03, 1.71) and higher ratio of n-6:n-3 FA (HR 1.37; 95 % CI 1.07, 1.77) during pregnancy were associated with an increased risk of allergic rhinitis in the offspring by 5 years of age. High maternal intakes of total PUFA (HR 0.71; 95 % CI 0.52, 0.96) and α-linolenic FA (HR 0.73; 95 % CI 0.54, 0.98) were associated with a decreased risk of allergic rhinitis. However, these results lost their significance after adjustment for multiple comparisons. Overall, our data suggest that maternal consumption of butter, the ratio of n-6:n-3 FA and intake of PUFA and α-linolenic FA during pregnancy may be potential determinants of allergic rhinitis in the offspring.

The gut as communicator between environment and host: immunological consequences

During human evolution, the mucosal immune system developed two anti-inflammatory mechanisms: immune exclusion by secretory antibodies (SIgA and SIgM) to control epithelial colonization of microorganisms and inhibit penetration of harmful substances; and immunosuppression to counteract local and peripheral hypersensitivity against innocuous antigens such as food proteins. The latter function is referred to as oral tolerance when induced via the gut. Similar mechanisms also control immunity to commensal bacteria. The development of immune homeostasis depends on "windows of opportunity" where adaptive and innate immunities are coordinated by antigen-presenting cells; their function is not only influenced by microbial products but also by dietary constituents, including vitamin A and lipids like polyunsaturated omega-3 fatty acids. These factors can in several ways exert beneficial effects on the immunophenotype of the infant. Also breast milk provides immune-modulating factors and SIgA antibodies - reinforcing the gut barrier. Mucosal immunity is most abundantly expressed in the gut, and the intestinal mucosa of an adult contains at least 80% of the body's activated B cells - terminally differentiated to plasmablasts and plasma cells (PCs). Most mucosal PCs produce dimeric IgA which is exported by secretory epithelia expressing the polymeric Ig receptor (pIgR), also called membrane secretory component (SC). Immune exclusion is therefore performed mainly by SIgA. Notably, pIgR knockout mice which lack SIgs show increased uptake of food and microbial antigens and they have a hyper-reactive immune system with disposition for anaphylaxis; but this untoward development is counteracted by cognate oral tolerance induction as a homeostatic back-up mechanism.

Neonatal tolerance under breastfeeding influence

Diseases due to defect in tolerance induction such as allergy, celiac disease, or Type 1 Diabetes develop mostly in childhood indicating the necessity of early intervention for primary prevention. Epidemiological studies report that breastfeeding could protect from these diseases. However, data are controversial and the mechanisms unclear. Experimental data suggest that breastfeeding-induced protection might rely on tolerance induction as long as some criteria are fulfilled. Thus, the tolerogenic potential of breast milk would depend on maternal exposure to common environmental and dietary antigens and the efficiency of antigen transfer across mammary epithelium. Induction of tolerance upon breast milk-mediated antigen transfer will also depend on the presence of immunomodulatory factors in breast milk and of its impact on neonatal gut and immune system maturation. The better understanding of maternal influence on tolerance induction through breastfeeding should allow the development of new strategies to prevent immune-mediated diseases.

Oral tolerance in neonates: from basics to potential prevention of allergic disease

Oral tolerance refers to the observation that prior feeding of an antigen induces local and systemic immune tolerance to that antigen. Physiologically, this process is probably of central importance for preventing inflammatory responses to the numerous dietary and microbial antigens present in the gut. Defective oral tolerance can lead to gut inflammatory disease, food allergies, and celiac disease. In the last two cases, the diseases develop early in life, stressing the necessity of understanding how oral tolerance is set up in neonates. This article reviews the parameters that have been outlined in adult animal models as necessary for tolerance induction and assesses whether these factors operate in neonates. In addition, we highlight the factors that are specific for this period of life and discuss how they could have an impact on oral tolerance. We pay particular attention to maternal influence on early oral tolerance induction through breast-feeding and outline the major parameters that could be modified to optimize tolerance induction in early life and possibly prevent allergic diseases.

Food allergy: separating the science from the mythology

Numerous genes are involved in innate and adaptive immunity and these have been modified over millions of years. During this evolution, the mucosal immune system has developed two anti-inflammatory strategies: immune exclusion by the use of secretory antibodies to control epithelial colonization of microorganisms and to inhibit the penetration of potentially harmful agents; and immunosuppression to counteract local and peripheral hypersensitivity against innocuous antigens, such as food proteins. The latter strategy is called oral tolerance when induced via the gut. Homeostatic mechanisms also dampen immune responses to commensal bacteria. The mucosal epithelial barrier and immunoregulatory network are poorly developed in newborns. The perinatal period is, therefore, critical with regard to the induction of food allergy. The development of immune homeostasis depends on windows of opportunity during which innate and adaptive immunity are coordinated by antigen-presenting cells. The function of these cells is not only orchestrated by microbial products but also by dietary constituents, including vitamin A and lipids, such as polyunsaturated omega-3 fatty acids. These factors may in various ways exert beneficial effects on the immunophenotype of the infant. The same is true for breast milk, which provides immune-inducing factors and secretory immunoglobulin A, which reinforces the gut epithelial barrier. It is not easy to dissect the immunoregulatory network and identify variables that lead to food allergy. This Review discusses efforts to this end and outlines the scientific basis for future food allergy prevention.

Asthma and allergic diseases in pregnancy a review

Asthma and allergic disorders can affect the course and outcome of pregnancy. Pregnancy itself may also affect the course of asthma and related diseases. Optimal management of these disorders during pregnancy is vital to ensure the welfare of the mother and the baby.Specific pharmacological agents for treatment of asthma or allergic diseases must be cautiously selected and are discussed here with respect to safety considerations in pregnancy. Although most drugs do not harm the fetus, this knowledge is incomplete. Any drug may carry a small risk that must be balanced against the benefits of keeping the mother and baby healthy. The goals and principles of management for acute and chronic asthma, rhinitis, and dermatologic disorders are the same during pregnancy as those for asthma in the general population.Diagnosis of allergy during pregnancy should mainly consist of the patient's history and in vitro testing.The assured and well-evaluated risk factors revealed for sensitization in mother and child are very limited, to date, and include alcohol consumption, exposure to tobacco smoke, maternal diet and diet of the newborn, drug usage, and insufficient exposure to environmental bacteria. Consequently, the recommendations for primary and secondary preventive measures are also very limited in number and verification.

Update on allergies in pregnancy, lactation, and early childhood

The factors responsible for the induction of allergic disease at an early age have not been completely identified. Therefore a major research focus is their identification to elaborate recommendations for prevention of sensitization in high-risk or atopic children. This review analyzes known or suspected reasons for sensitization in pregnant women and infants from both clinical and experimental animal studies. Recent studies and meta-analyses could not confirm the protective effect of an allergen-poor diet on the part of the mother during pregnancy and lactation. Likewise, the type of bottle feeding or the introduction of solid food into the child's diet might not significantly influence the development of atopy, allergy, or asthma in the child's life. Disappointingly, the few preventive measures remaining to reduce the risk of allergic sensitization and atopic diseases in mother and child are the avoidance of smoking and alcohol consumption during pregnancy and lactation and the avoidance of the impairment of gastric function. Further studies are urgently needed to address the influence of certain foods and nutrients, as well as environmental factors, for prevention of allergic diseases in the low- or high-risk infant.

Fatty acid composition of serum lipid classes in mice following allergic sensitisation with or without dietary docosahexaenoic acid-enriched fish oil substitution

Dietary fatty acids have been shown to influence allergic sensitisation. Bothn-3 andn-6 PUFA are involved in targeted mediation of inflammatory responses during allergic sensitisation and manifestation of atopic diseases. In the present experiments we investigated whether supplementation of DHA-enriched fish oil partly substituting dietary sunflower-seed oil, in comparison with sunflower-seed oil, supplemented to mice influences fatty acid composition of serum lipid classes. The effects of the two different diets were also investigated depending on allergic sensitisation. Supplementation of DHA and EPA in doses of 2 and 0·12 % (w/w) to non-sensitised and sensitised mice resulted in significantly increased percentile contributions of DHA to all lipid classes. In contrast, serum values of then-6 PUFA arachidonic acid (AA) were significantly lower, both in non-sensitised and sensitised mice fed the DHA-enriched diet. The fatty acid composition of serum lipids also reflected allergic sensitisation: the EPA:AA ratio in TAG, cholesteryl esters and phospholipids in non-supplemented animals fell to 23, 29 and 29 % respectively of the original value after allergic sensitisation, whereas it decreased to 70, 80 and 76 % respectively only in the animals supplemented with DHA. In summary, allergic sensitisation alone decreased significantly the EPA:AA ratios in serum TAG, while concomitant supplementation of DHA-enriched fish oil ameliorated this decrease. We postulate from the present results that the amelioration of the severity of allergic sensitisation after DHA supplementation may be linked to altered ratios of the eicosanoid precursors EPA and AA as well as DHA needed for further metabolic activation to pro- or anti-inflammatory bioactive lipids.

Interactions between protein and vegetable oils in the maternal diet determine the programming of the insulin axis in the rat

The available evidence suggests that metabolic control mechanisms are programmed early in life. Previous studies of pregnant rats fed low-protein diets have suggested that the vegetable oils used in the experimental diets influence the outcome. The present study investigated the offspring of female rats fed semi-synthetic diets containing either 180 or 90 g casein/kg with 70 g/kg (w/w) of either corn oil or soya oil during gestation. During lactation, the dams received stock diet, and the offspring were subsequently weaned onto the stock diet. The offspring of dams fed the low-protein diets were smaller at birth. At 25 weeks of age, the offspring were subjected to an oral glucose tolerance test. In the offspring of dams fed the diet containing soya oil, the area under the insulin curve was affected by the protein content of the maternal diet. There was no effect of protein on the area under the insulin curve in the offspring of dams fed the diet prepared with corn oil. There were no differences in plasma glucose concentrations. The levels of mRNA for acetyl-CoA carboxylase-1 in the livers of female offspring were affected by the protein and oil content of the maternal diet. The level of carnitine palmitoyl transferase mRNA was affected by the protein content of the maternal diet. The present study suggests that PUFA in the maternal diet can interact with protein metabolism to influence the development of the offspring. This may involve the higher content of α-linolenic acid in soya oil compared with corn oil.

Consumption of omega3-fatty acids during perinatal life: role in immuno-modulation and allergy prevention

Epidemiological data suggest that dietary factors may have a role in recent increases of the prevalence of allergic diseases. One food-related component might be the reduced consumption of omega3-polyunsaturated fatty acids observed especially in the Western societies; yet, clinical trials supplementing omega3-fatty acids to adults with established allergies and bronchial asthma have generally been disappointing. However, it is known that the immature immune system is highly susceptible to immuno-modulatory environmental conditions particularly in the pre- and postnatal period. This review discusses the immuno-modulatory effects of omega3-fatty acids supplementation in the perinatal life phase on the immune system of the child. Evidence exists that perinatal omega3-fatty acid exposure affects T-cells and antigen presenting cells of the neonates likely due to altered eicosanoid metabolism. Although animal experiments strongly suggest a role of maternal omega3-fatty acid intake on allergic immune responses in the offspring, the beneficial effect of omega3-fatty acid supplementation has been studied in a small number of clinical trials. In these studies perinatal supplementation had some positive effects on distinct clinical phenotypes of the atopic syndrome. However, more studies are needed to fully explore the opportunity of perinatal immuno-modulation.

Serum, cheek cell and breast milk fatty acid compositions in infants with atopic and non-atopic eczema

BACKGROUND

The major theory implicating diet with allergic diseases is associated with altered food consumption and subsequent changes in fatty acid composition.

OBJECTIVE

To investigate fatty acid compositions among infants with atopic and non-atopic eczema and healthy infants and to evaluate the expediency of non-invasive cheek cell phospholipid fatty acid composition as a marker in patients with eczema.

METHODS

Diagnosis of eczema in infants was confirmed clinically and by positive (atopic eczema, n=6) or negative (non-atopic eczema, n=6) skin prick testing in comparison with controls (n=19). The fatty acid compositions of infant cheek cell and serum phospholipids and breast milk total lipids were analysed by gas chromatography.

RESULTS

The distinction between atopic and non-atopic eczema was manifested in cheek cell phospholipids as linoleic acid (14.69 (13.67-15.53)% of total fatty acids; the median (interquartile range)), the sum of n-6 fatty acids (19.94 (19.06-20.53)%) and the sum of polyunsaturated fatty acids (22.70 (21.31-23.28)%) were higher in infants with atopic eczema compared with non-atopic eczema (12.69 (10.87-13.93); 17.72 (15.63-18.91) and 19.90 (17.64-21.06), respectively; P<0.05) and controls (12.50 (12.16-13.42); 18.19 (17.43-18.70) and 20.32 (19.32-21.03), respectively; P<0.05). Serum phospholipid gamma-linolenic acid was lower in both atopic and non-atopic eczema compared with controls (P<0.05) and additionally eicosapentaenoic acid was higher in atopic eczema compared with controls (P<0.05).

CONCLUSION

These preliminary results suggest differences in fatty acid compositions between the two types of eczema, calling for further evaluation in a larger setting. The two types of eczema may be regulated by different immunological processes, and fatty acids may have a more profound role in the atopic type.

Diet of lactating women and allergic reactions in their infants

PURPOSE OF REVIEW

To evaluate whether the diet of lactating women modulates the development of allergic disease in their children.

RECENT FINDINGS

Although maternal avoidance of common food protein allergens was previously recommended for lactating women with infants predisposed to allergic disease, recent expert reviews have concluded that there is no strong evidence to support this position. A recent well-controlled study, using egg as an allergen, confirmed that the appearance of food proteins in human milk is common, but this can be highly variable between women even after consuming the same challenge (dose) food. On the other hand, preliminary data suggest that increasing dietary n-3 fatty acids may offer protection from the development of some childhood allergies. A recent animal study offers mechanistic support, indicating that perinatal diets high in n-3 fatty acids can induce oral neonatal tolerance more effectively compared with diets predominating in n-6 fatty acids.

SUMMARY

Current data do not support the use of maternal antigen-avoidance diets during lactation as a strategy to prevent childhood allergies. Controlled trials are required to evaluate the efficacy of maternal dietary n-3 fatty acid interventions in preventing allergic disease in at-risk infants.

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.