Maternal diet and its influence on the development of allergic disease

Novel Perspective on the Regulation of Offspring Food Allergy by Maternal Diet and Nutrients

There has been a dramatic surge in the prevalence of food allergy (FA) that cannot be explained solely by genetics, identifying mechanisms of sensitization that are driven by environmental factors has become increasingly important. Diet, gut microbiota, and their metabolites have been shown to play an important role in the development of FA. In this review, we discuss the latest epidemiological evidence on the impact of two major dietary patterns and key nutrients in early life on the risk of offspring developing FA. The Western diet typically includes high sugar and high fat, which may affect the immune system of offspring and increase susceptibility to FA. In contrast, the Mediterranean diet is rich in fiber, which may reduce the risk of FA in offspring. Furthermore, we explore the potential mechanisms by which maternal dietary nutrients during a window of opportunity (pregnancy, birth, and lactation) influences the susceptibility of offspring to FA through multi-interface crosstalk. Finally, we discuss the limitations and gaps in the available evidence regarding the relationship between maternal dietary nutrients and the risk of FA in offspring. This review provides novel perspective on the regulation of offspring FA by maternal diet and nutrients.

Insights from the COCOA birth cohort: The origins of childhood allergic diseases and future perspectives

The ongoing COhort for Childhood Origin of Asthma and allergic diseases (COCOA) study is a prospective birth cohort investigating the origin and natural courses of childhood allergic diseases, including atopic dermatitis, food allergy, allergic rhinitis and asthma, with long-term prognosis. Initiated under the premise that allergic diseases result from a complex interplay of immune development alterations, environmental exposures, and host susceptibility, the COCOA study explores these dynamic interactions during prenatal and postnatal periods, framed within the hygiene and microbial hypotheses alongside the developmental origins of health and disease (DOHaD) hypothesis. The scope of the COCOA study extends to genetic predispositions, indoor and outdoor environmental variables affecting mothers and their offsprings such as outdoor and indoor air pollution, psychological factors, diets, and the microbiomes of skin, gut, and airway. We have embarked on in-depth investigations of diverse risk factors and the pathophysiological underpinnings of allergic diseases. By employing multi-omics approaches-proteomics, transcriptomics, and metabolomics-we gain deeper insights into the distinct pathophysiological processes across various endotypes of childhood allergic diseases, incorporating the exposome using extensive resources within the COCOA study. Integration with large-scale datasets, such as national health insurance records, enhances robustness and mitigates potential limitations inherent to birth cohort studies. As part of global networks focused on childhood allergic diseases, the COCOA study fosters collaborative research across multiple cohorts. The findings from the COCOA study are instrumental in informing precision medicine strategies for childhood allergic diseases, underpinning the establishment of disease trajectories.

Maternal Macro- and Micronutrient Intake During Pregnancy: Does It Affect Allergic Predisposition in Offspring?

This review article explores the available literature on the association of maternal nutrient intake with development of allergies in offspring. It examines the mechanisms for maternal diet-mediated effects on offspring immunity and dissects recent human and animal studies that evaluate the role of both maternal macro- and micronutrient intake on offspring susceptibility to asthma, eczema, food allergy, and atopy.

How advanced are we on the consequences of oral exposure to food contaminants on the occurrence of chronic non communicable diseases?

The development of an individual during fetal life and childhood is characterized by rapid growth as well as gradual maturation of organs and systems. Beyond the nutritional intake in essential nutrients, food contaminants can permanently influence the way organs mature and function. These processes are called "programming" and play an essential role in the occurrence of non-communicable chronic diseases throughout the lifespan. Populations as pregnant women, fetuses and young children are vulnerable and particularly sensitive to food contaminants which can induce epigenetic modifications transmissible to future generations. Among these contaminants, pesticides are found in most food matrices exposing humans to cocktails of molecules through variable concentrations and duration of exposure. The Maillard reaction products (MRPs) represent other food contaminants resulting from heat treatment of food. Modern diet, rich in fats and sugars, is also rich in neoformed pathogenic compounds, Advanced Glycation End products (AGEs), the levels of which depend on the heat treatment of foods and eating habits and whose effects on health are controversial. In this review, we have chosen to present the current knowledge on the impacts of selected pesticides and MRPs, on the risk of developing during life non-communicable chronic diseases such as IBD, metabolic disorders or allergies. A large review of literature was performed via Pubmed, and the most appropriate studies were summarised.

Guideline No. 427: Folic Acid and Multivitamin Supplementation for Prevention of Folic Acid-Sensitive Congenital Anomalies

OBJECTIVE

To provide updated guidance on pre-conception folic acid and multivitamin supplementation for primary and secondary (recurrence) prevention of neural tube defects and other folate-sensitive congenital anomalies.

TARGET POPULATION

Women aged 12-45 years who could become pregnant should be aware of the risk of serious birth defects without adequate pre-conception and first-trimester folic acid supplementation.

OPTIONS

Optimizing folic acid supplementation is complex and depends on factors including dosage; type of supplement; bioavailability of folate from food, timing of initiating supplementation; and metabolic and genetic factors. For all women who could become pregnant, a low daily dosage of folic acid is recommended before conception and throughout pregnancy and breastfeeding. High-dosage folic acid supplementation is recommended only for women who can become pregnant and have had a previous pregnancy affected by a neural tube defect or other folate-sensitive congenital anomaly. Directed personalized approaches could be considered and adopted for women who can become pregnant and have complex risks (genetic, medical, or surgical risk factors), using new knowledge of co-factor metabolism and synergy, as well as red blood cell or serum folate testing. Such approaches would require changes to current provincial health care maternal serum folate screening/testing.

OUTCOMES

New approaches to oral folic acid supplementation, including triage tools, need to be considered to optimize the benefits of decreasing risk of neural tube defects and folate-sensitive congenital anomalies.

BENEFITS, HARMS, AND COSTS

Oral folic acid supplementation, or dietary folate intake combined with a multivitamin/micronutrient supplement, is associated with lower rates of neural tube defects, other folate-sensitive birth defects, and obstetrical complications. The costs are those attributable to daily vitamin supplementation and a healthy, folate-rich diet.

EVIDENCE

A literature search was designed and carried in PubMed and the Cochrane Library databases from 1990 to 2021 using following MeSH terms and keywords (and variants): folic acid supplementation; folate food fortification; primary neural tube defect prevention; prevention of recurrence of neural tube defects; folate-sensitive birth defects; folate supplementation benefit; folate supplementation risk; folate pregnant woman physiology; pregnant woman RBC folate level; pregnant woman serum folate levels; folate and epilepsy; folate and obesity. This guideline was based upon expert guidelines or opinions, systematic reviews, randomized controlled clinical trials, and observational case-control studies and case series retrieved, published in English from 1990 to 2021.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Maternity health care providers (physicians, midwives, nurses) and other providers of pregnancy-related wellness and health counselling.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Directive clinique no427 : Suppléments d'acide folique et multivitamines en prévention des anomalies congénitales sensibles à l'acide folique

OBJECTIF

Offrir des recommandations à jour sur l'utilisation de multivitamines et de suppléments d'acide folique avant la conception pour la prévention primaire et secondaire (récidive) des anomalies du tube neural et des autres anomalies congénitales sensibles à l'acide folique.

POPULATION CIBLE

Les femmes de 12 à 45 ans qui pourraient devenir enceintes doivent être informées des risques importants d'anomalies congénitales en l'absence d'une supplémentation adéquate en acide folique avant la conception et pendant le premier trimestre.

OPTIONS

La supplémentation optimale en acide folique est complexe et repose sur divers facteurs tels que la dose, le type de suppléments, la biodisponibilité du folate dans l'alimentation, le moment du début de la supplémentation ainsi que sur les facteurs métaboliques et génétiques. Pour toutes les femmes qui peuvent devenir enceintes, une faible dose quotidienne d'acide folique est recommandée avant la conception et pendant la grossesse et l'allaitement. La supplémentation à forte dose d'acide folique est recommandée uniquement chez les femmes qui peuvent devenir enceintes et qui ont un antécédent de grossesse avec anomalie du tube neural ou toute autre anomalie congénitale sensible à l'acide folique. Il est possible d'envisager et d'adopter une approche personnalisée chez les femmes qui peuvent devenir enceintes et qui présentent des risques complexes (facteurs de risque génétiques, médicaux ou chirurgicaux) en se fondant sur les nouvelles connaissances en matière de métabolisme et synergie des cofacteurs et sur l'analyse du taux sérique et érythrocytaire d'acide folique. Ce genre d'approche exige une modification des protocoles provinciaux actuels de santé publique concernant le dépistage et l'analyse du taux sérique maternel d'acide folique. RéSULTATS: Les nouvelles stratégies de supplémentation en acide folique par voie orale, y compris dans les outils de triage, doivent être prises en compte pour diminuer de façon optimale le risque d'anomalies du tube neural et d'anomalies congénitales sensibles à l'acide folique. BéNéFICES, RISQUES ET COûTS: On observe une diminution du taux d'anomalies du tube neural, des autres anomalies congénitales sensibles à l'acide folique et des complications obstétricales chez les femmes qui prennent des suppléments oraux d'acide folique ou qui complémentent leur apport alimentaire en folate au moyen de multivitamines ou de suppléments de micronutriments. Les coûts relatifs sont liés à la prise quotidienne de suppléments vitaminiques et à l'adoption d'un régime alimentaire sain et riche en folate. DONNéES PROBANTES: Une recherche a été effectuée dans les bases de données PubMed et Cochrane Library pour trouver des articles publiés entre 1990 et 2021, en utilisant les termes MeSH et mots-clés (et leurs variantes) suivants : folate food fortification; primary neural tube defect prevention; prevention of recurrence of neural tube defects; folate-sensitive birth defects; folate supplementation benefit; folate supplementation risk; folate pregnant woman physiology; pregnant woman RBC folate level; pregnant woman serum folate levels; folate and epilepsy; folate and obesity. Cette directive clinique repose sur des lignes directrices et opinions de spécialistes, des revues systématiques, des essais cliniques randomisés et des études observationnelles de cas-témoin et de séries de cas qui ont été publiés en anglais entre 1990 et 2021. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Fournisseurs de soins de maternité (médecins, sages-femmes et infirmières) et autres fournisseurs d'accompagnement en santé et bien-être lié à la grossesse. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Alternatives to Cow’s Milk-Based Infant Formulas in the Prevention and Management of Cow’s Milk Allergy

Cow’s milk-based infant formulas are the most common substitute to mother’s milk in infancy when breastfeeding is impossible or insufficient, as cow’s milk is a globally available source of mammalian proteins with high nutritional value. However, cow’s milk allergy (CMA) is the most prevalent type of food allergy among infants, affecting up to 3.8% of small children. Hypoallergenic infant formulas based on hydrolysed cow’s milk proteins are commercially available for the management of CMA. Yet, there is a growing demand for more options for infant feeding, both in general but especially for the prevention and management of CMA. Milk from other mammalian sources than the cow, such as goat, sheep, camel, donkey, and horse, has received some attention in the last decade due to the different protein composition profile and protein amino acid sequences, resulting in a potentially low cross-reactivity with cow’s milk proteins. Recently, proteins from plant sources, such as potato, lentil, chickpeas, quinoa, in addition to soy and rice, have gained increased interest due to their climate friendly and vegan status as well as potential lower allergenicity. In this review, we provide an overview of current and potential future infant formulas and their relevance in CMA prevention and management.

Maternal Nutritional Status and Development of Atopic Dermatitis in Their Offspring

Atopic dermatitis (AD) is the leading chronic skin inflammatory disease and the initial manifestation of atopic march. Available evidence supports the notion that primary prevention early in life leads to a decreased incidence of AD, thus possibly decreasing the subsequent occurrence of atopic march. Nutritional status is essential to a proper functioning immune system and is valued for its important role in AD. Essential nutrients, which include carbohydrates, proteins, lipids, vitamins, and minerals, are transferred from the mother to the fetus through the placenta during gestation. Various nutrients, such as polyunsaturated fatty acids (PUFAs) and vitamin D, were studied in relation to maternal status and offspring allergy. However, no strong evidence indicates that a single nutrient or food in mothers' diet significantly affects the risk of childhood AD. In the light of current evidence, mothers should not either increase nor avoid consuming these nutrients to prevent or ameliorate allergic diseases in their offspring. Each essential nutrient has an important role in fetal development, and current government recommendations suggest specific intake amounts for pregnant women. This review discusses evidence on how various nutrients, including lipids (monounsaturated fatty acids, PUFAs, saturated fatty acids, and short-chain fatty acids), carbohydrates (oligosaccharides and polysaccharides), proteins, vitamins (A, B, C, D, and E), and trace minerals (magnesium, iron, zinc, copper, selenium, and strontium) in maternal status are associated with the development of AD and their possible mechanisms.

Maternal caffeine intake during pregnancy and risk of food allergy in young Japanese children

AIM

To examine the association between maternal caffeine intake during pregnancy and the development of food allergy in young Japanese children up to 3 years of age.

METHODS

The study involved 1522 mother-child pairs. Data on maternal caffeine intake during pregnancy were assessed with a validated diet history questionnaire. Food allergy was defined by a self-reported claim of having a physicians' diagnosis of food allergy or of having an acute reaction to a food.

RESULTS

Compared with the lowest tertile of maternal caffeine intake during pregnancy, the second tertile, but not the highest tertile, was significantly associated with an increased risk of food allergy. Further adjustment on suspicion or diagnosis of atopic eczema at around 4 months postpartum in a follow-up survey did not substantially change the association between maternal caffeine intake during pregnancy and the risk of food allergy in children: further adjusted hazard ratios (95% confidence intervals) for the second (T2), the highest tertiles (T3) and the second and the highest tertiles combined (T2 + T3) were 1.46 (1.10-1.96), 1.16 (0.85-1.56) and 1.31 (1.01-1.70), respectively.

CONCLUSIONS

Our findings suggest that maternal caffeine intake during pregnancy may be positively associated with the risk of food allergy in children.

Maternal periconceptional folate status and infant atopic dermatitis: A prospective cohort study

BACKGROUND

Maternal folate status is linked with the risk of allergic disorders including atopic dermatitis (AD) in children, but findings remain inconclusive. We aim to assess the relationship between maternal folate status in early gestation and early-onset infant AD, based on a prospective mother-child cohort study.

METHODS

Pregnant women were recruited at 12-14 weeks of gestation. Red blood cell folate (RBC folate) and serum folate concentrations were examined at enrollment. Periconceptional folic acid supplementation was investigated through a self-administered questionnaire. The primary outcome was AD incidence before 6 months of age, diagnosed according to Williams' criteria. Multivariate logistic regression was used to evaluate associations of maternal folate status with infant AD by adjusting parental and child covariates.

RESULTS

In total, 107 (23.4%) of 458 infants developed AD before 6 months, with more male infants affected (P = .002). Higher maternal RBC folate levels (per 100 ng/mL) were associated with an increased risk of AD (adjusted odds ratio [aOR] 1.16, 95% confidence interval [CI] 1.04-1.31). An RBC folate level ≥620 ng/mL was associated with increased infant AD by 91% (aOR 1.91, 95% CI 1.09-3.36). However, associations were not observed for maternal serum folate at early gestation or periconceptional folic acid supplement intakes.

CONCLUSIONS

We provide the first evidence that higher maternal RBC folate concentrations during early gestation are associated with increased early-onset infant AD. Our findings support the importance of maintaining appropriate folate levels during the periconceptional period to reduce the risk of AD in infants.

Maternal Resveratrol Treatment Re-Programs and Maternal High-Fat Diet-Induced Retroperitoneal Adiposity in Male Offspring

Obesity during pregnancy increases the risk of cardiovascular problems, diabetes, asthma, and cognitive impairments, affecting the offspring. It is important to reduce the negative effects of obesity and high-fat (HF) diet during pregnancy. We employed a rat model of maternal HF diet to evaluate the possible de-programming effects of resveratrol in rodent male offspring with maternal HF diet/obesity. Male rat offspring were randomized into four groups: maternal control diet/postnatal control diet, maternal HF diet/postnatal control diet, maternal control diet plus maternal resveratrol treatment/postnatal control diet, and maternal HF diet plus maternal resveratrol treatment/postnatal control diet. Maternal HF diet during pregnancy plus lactation resulted in retroperitoneal adiposity in the male offspring. Maternal resveratrol treatment re-programmed maternal HF exposure-induced visceral adiposity. Offspring that received prenatal HF diet showed higher leptin/soluble leptin receptor (sOB-R) ratio than offspring that received prenatal control diet. Maternal resveratrol treatment ameliorated maternal HF exposure-induced increase in leptin/sOB-R ratio and altered the expression of genes for crucial fatty acid synthesis enzymes in the offspring. Thus, maternal resveratrol administration reduces retroperitoneal adiposity in rat offspring exposed to prenatal HF diet/obesity and could be used to ameliorate negative effects of maternal HF diet in the offspring.

Prenatal Omega-3 and Omega-6 Polyunsaturated Fatty Acids and Childhood Atopic Dermatitis

BACKGROUND

Atopic dermatitis is a common childhood disease, potentially influenced by prenatal nutritional exposures such as polyunsaturated fatty acids (PUFAs).

OBJECTIVE

In a racially diverse cohort, we hypothesized that childhood atopic dermatitis would be associated with higher prenatal omega-6 (n-6) and lower omega-3 (n-3) PUFAs.

METHODS

We included mother-child dyads, births 2006 to 2011, enrolled in the University of Tennessee Health Sciences Center Conditions Affecting Neurocognitive Development in Early Childhood cohort. Primary exposures included second trimester plasma n-3 and n-6 PUFA status and the ratio of the two (n-6:n-3). We assessed child current atopic dermatitis symptoms in the previous 12 months at age approximately 4 to 6 years. We investigated the association between PUFA exposures and atopic dermatitis using multivariable logistic regression, adjusting for potential confounders. We assessed for effect modification by maternal prenatal smoking, atopic disease history, and child sex.

RESULTS

Among 1131 women, 67% were African American and 42% had an atopic disease history; 17% of children had atopic dermatitis. Higher prenatal n-6 PUFAs were associated with increased relative odds of child atopic dermatitis (adjusted odds ratio: 1.25; confidence interval: 1.01-1.54 per interquartile range difference), and interaction models demonstrated that this association was seen in dyads in which the women had a history of atopic disease. Neither prenatal n-3 PUFAs nor n-6:n-3 were associated with child atopic dermatitis.

CONCLUSION

In this racially diverse cohort, higher second trimester n-6 PUFAs were associated with atopic dermatitis in children of women with atopy. PUFAs may represent a modifiable risk factor for atopic dermatitis, particularly in individuals with a familial predisposition.

Influences of Maternal Factors Over Offspring Allergies and the Application for Food Allergy

The prevalence of food allergy has been steadily rising worldwide with the highest incidence noted among younger children, and increasingly recognized as a growing public concern. The first known ingestion of foods often causes allergic reaction, suggesting that sensitization of offspring with food allergens may occur during pregnancy and/or through breastfeeding. This creates a milieu that shapes the neonatal immune responses to these allergens. However, the effects of maternal allergen exposure and maternal sensitization with allergens on development of allergies in offspring remain controversial. This review discusses recent advances from human data in our understanding of how maternal factors, namely, food allergens, allergen-specific immunoglobulins, cytokines, genetics, and environmental factors transferred during pregnancy or breastfeeding influence offspring allergies and how such effects may be applicable to food allergy. Based on information obtained from mouse models of asthma and food allergy, the review also dissects the mechanisms by which maternal factors, including the impact of immune complexes, transforming growth factor-β, vitamin A, and regulatory T-cell responses, contribute to the induction of neonatal tolerance vs. development of allergic responses to maternally transferred allergens.

Pregnancy diet and offspring asthma risk over a 10-year period: the Lifeways Cross Generation Cohort Study, Ireland

OBJECTIVE

The association of maternal pregnancy diet with offspring asthma risk have been reported. However, literature on longitudinal patterns of asthma risk relative to intrauterine nutrient exposure is limited. We aimed to establish whether vegetable, oily fish and vitamin D intake during pregnancy are associated with childhood asthma risk over a 10-year period in the Irish Republic.

DESIGN

Mother-child pairs (n=897) from the Lifeways prospective birth cohort, with data on nutrient intake during pregnancy and asthma status, respectively, were eligible for inclusion in the analysis. Data on socioeconomic and morbidity indicators over 10 years of follow-up on mothers and the index child were collected through self-administered questionnaires. Asthma status as diagnosed by the general practitioner at any time point over 10 years was related to maternal vegetable, oily fish and vitamin D intake during pregnancy, while adjusting for gestational age, socioeconomic status, smoking at delivery, breast feeding, season of birth and supplement use. Data were modelled with a marginal model on correlated observations over time within individuals.

RESULTS

In the fully adjusted model, asthma was inversely associated with higher daily average intake of oily fish (OR 0.23 per serving/day, 95% CI 0.04 to 1.41) and of vegetables (OR 0.96 per serving/day, 95% CI 0.88 to 1.05), but the confidence limits overlapped 1. A higher daily vitamin D intake was associated with reduced odds of asthma (OR 0.93 per μg/day, 95% CI 0.89 to 0.98).

CONCLUSION

This analysis suggests higher daily average intake of vitamin D in pregnancy is associated with asthma risk in offspring over the first 10 years of life.

Breastfeeding and perinatal exposure, and the risk of asthma and allergies

PURPOSE OF REVIEW

Exposures during the perinatal period, a phase of rapid development, may have a profound and sustained effect on disease risk. In particular, perinatal exposures may influence the development and maturation of the infant immune system and the risk of allergic disease. We aimed to summarize the current literature on perinatal exposures and the risk of asthma and allergic disease

RECENT FINDINGS

Increased risk of offspring wheeze or asthma was found for: maternal obesity and hypertension during pregnancy; febrile illness, gynaecological, and viral respiratory infections in pregnancy; exposure to bisphenol A and phthalates in pregnancy and childhood; exposure to smoking in utero; low birth weight; caesarean section and neonatal hyperbilirubinaemia. Reduced risk of offspring atopic eczema was found for hookworm infection in pregnancy and reduced risk of offspring wheeze was associated with increased pregnancy dietary intake of vitamin E and zinc. Higher levels of selenium in pregnancy were associated with less risk of asthma in genetically susceptible offspring. Early life pet ownership was associated with a decrease in atopic asthma but an increase in nonatopic asthma risk.

SUMMARY

A diverse range of exposures were associated with allergic disease risk, highlighting the susceptibility of children during the perinatal period. Clinicians should reinforce public health messages concerning maternal obesity, smoking, and breastfeeding. The infant gut microbiome is emerging as an important hypothesis, which may mediate the relationship between many perinatal exposures and allergic disease.

Nutrition and Allergic Diseases

The development of IgE-mediated allergic diseases is influenced by many factors, including genetic and environmental factors such as pollution and farming, but also by nutrition. In the last decade, substantial progress has been made in our understanding of the impact that nutrition can have on allergic diseases. Many studies have addressed the effect of breastfeeding, pre-, pro- and synbiotics, vitamins and minerals, fiber, fruit and vegetables, cow's milk, and n-3 fatty acids, on the development of allergies. In addition, nutrition can also have indirect effects on allergic sensitization. This includes the diet of pregnant and breastfeeding women, which influences intrauterine development, as well as breastmilk composition. These include the diet of pregnant and breastfeeding women that influences intrauterine development as well as breastmilk composition, effects of food processing that may enhance allergenicity of foods, and effects via modulation of the intestinal microbiota and their metabolites. This editorial review provides a brief overview of recent developments related to nutrition and the development and management of allergic diseases.

Allergic diseases and asthma in pregnancy, a secondary publication

Every fifth pregnant woman is affected by allergies, especially rhinitis and asthma. Allergic symptoms existing before pregnancy may be either attenuated, or equally often promoted through pregnancy. Optimal allergy and asthma diagnosis and management during pregnancy is vital to ensure the welfare of mother and baby. For allergy diagnosis in pregnancy, preferentially anamnestic investigation as well as in vitro testing should be applied, whereas skin testing or provocation tests should be postponed until after birth. Pregnant women with confirmed allergy should avoid exposure to, or consumption of the offending allergen. Allergen immunotherapy should not be initiated during pregnancy. In patients on immunotherapy since before pregnancy, maintenance treatment may be continued, but the allergen dose should not be increased further. Applicable medications for asthma, rhinitis or skin symptoms in pregnancy are discussed and listed. In conclusion, i) allergies in pregnancy should preferentially be diagnosed in vitro; ii) AIT may be continued, but not started, and symptomatic medications must be carefully selected; iii) management of asthma and allergic diseases is important during pregnancy for welfare of mother and child.

Maternal Folic Acid Supplementation during Pregnancy and Childhood Allergic Disease Outcomes: A Question of Timing?

Since the early 1990s, maternal folic acid supplementation has been recommended prior to and during the first trimester of pregnancy, to reduce the risk of infant neural tube defects. In addition, many countries have also implemented the folic acid fortification of staple foods, in order to promote sufficient intakes amongst women of a childbearing age, based on concerns surrounding variable dietary and supplementation practices. As many women continue to take folic acid supplements beyond the recommended first trimester, there has been an overall increase in folate intakes, particularly in countries with mandatory fortification. This has raised questions on the consequences for the developing fetus, given that folic acid, a methyl donor, has the potential to epigenetically modify gene expression. In animal studies, folic acid has been shown to promote an allergic phenotype in the offspring, through changes in DNA methylation. Human population studies have also described associations between folate status in pregnancy and the risk of subsequent childhood allergic disease. In this review, we address the question of whether ongoing maternal folic acid supplementation after neural tube closure, could be contributing to the rise in early life allergic diseases.

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.

The role of gene-environment interactions in the development of food allergy

The rates of IgE-mediated food allergy have increased globally, particularly in developed countries. The rising incidence is occurring more rapidly than changes to the genome sequence would allow, suggesting that environmental exposures that alter the immune response play an important role. Genetic factors may also be used to predict an increased predisposition to these environmental risk factors, giving rise to the concept of gene-environment interactions, whereby differential risk of environmental exposures is mediated through the genome. Increasing evidence also suggests a role for epigenetic mechanisms, which are sensitive to environmental exposures, in the development of food allergy. This paper discusses the current state of knowledge regarding the environmental and genetic risk factors for food allergy and how environmental exposures may interact with immune genes to modify disease risk or outcome.

Maternal dietary folate, folic acid and vitamin D intakes during pregnancy and lactation and the risk of cows’ milk allergy in the offspring

Maternal nutrient intake during pregnancy and lactation potentially influences the development of allergic diseases. Cows’ milk allergy (CMA) is often the first manifestation of atopic diseases, but the impact of early nutritional influences on CMA has not been explored. The associations between maternal intakes of folate, folic acid and vitamin D during pregnancy and lactation were addressed in a prospective, population-based birth cohort within the Finnish Type 1 Diabetes Prediction and Prevention Study. Mothers of 4921 children during pregnancy and 2940 children during lactation provided information on maternal dietary intake during the 8th month of pregnancy and the 3rd month of lactation using a detailed, validated FFQ. Information on diagnosed CMA in the offspring was obtained from a medical registry as well as queried from the parents. The Finnish food composition database was used to calculate nutrient intake. Logistic regression was applied for statistical analyses. Folate intake and folic acid and vitamin D supplement use were associated with an increased risk of CMA in the offspring, whereas vitamin D intake from foods during pregnancy was associated with a decreased risk of CMA. Thus, maternal nutrient intake during pregnancy and lactation may affect the development of CMA in offspring. Supplementation with folic acid may not be beneficial in terms of CMA development, especially in children of allergic mothers. The association between dietary supplement use and CMA risk can at least partly be explained by increased health-seeking behaviour among more educated mothers who also use more dietary supplements.

Developmental origins of inflammatory and immune diseases

Epidemiological and experimental animal studies show that suboptimal environments in fetal and neonatal life exert a profound influence on physiological function and risk of diseases in adult life. The concepts of the 'developmental programming' and Developmental Origins of Health and Diseases (DOHaD) have become well accepted and have been applied across almost all fields of medicine. Adverse intrauterine environments may have programming effects on the crucial functions of the immune system during critical periods of fetal development, which can permanently alter the immune function of offspring. Immune dysfunction may in turn lead offspring to be susceptible to inflammatory and immune diseases in adulthood. These facts suggest that inflammatory and immune disorders might have developmental origins. In recent years, inflammatory and immune disorders have become a growing health problem worldwide. However, there is no systematic report in the literature on the developmental origins of inflammatory and immune diseases and the potential mechanisms involved. Here, we review the impacts of adverse intrauterine environments on the immune function in offspring. This review shows the results from human and different animal species and highlights the underlying mechanisms, including damaged development of cells in the thymus, helper T cell 1/helper T cell 2 balance disturbance, abnormal epigenetic modification, effects of maternal glucocorticoid overexposure on fetal lymphocytes and effects of the fetal hypothalamic-pituitary-adrenal axis on the immune system. Although the phenomena have already been clearly implicated in epidemiologic and experimental studies, new studies investigating the mechanisms of these effects may provide new avenues for exploiting these pathways for disease prevention.

Update on Early Nutrition and Food Allergy in Children

With growing evidence of an increase in the prevalence, food allergy has been emerged as a new public health problem. As treatment and management of food allergy remain challenging, more attention has been paid to the importance of prevention of food allergy. Although the exact mechanism of recent epidemic is not fully understood, it is suggested that nutritional exposure in early life may play an important role in food allergy development. The underlying hypothesis is that nutritional status or food exposure in the critical period of fetal development can affect the programming of immune system and modify the risk of immunologic reactions to foods in postnatal life. We review accumulating epidemiological studies to examine an association between nutritional exposure during pregnancy or early infancy and food allergy development in children. We also discuss recent advances in the studies of the genetic and epigenetic regulation of food allergy and evaluate the role of early nutrition in food allergy development to provide a new perspective on the prevention of food allergy.

Dietary n-3 long chain polyunsaturated fatty acids in allergy prevention and asthma treatment

The rise in non-communicable diseases, such as allergies, in westernized countries links to changes in lifestyle and diet. N-3 long chain polyunsaturated fatty acids (LCPUFA) present in marine oils facilitate a favorable milieu for immune maturation and may contribute to allergy prevention. N-3 LCPUFA can suppress innate and adaptive immune activation and induce epigenetic changes. Murine studies convincingly show protective effects of fish oil, a source of n-3 LCPUFA, in food allergy and asthma models. Observational studies in human indicate that high dietary intake of n-3 LCPUFA and low intake of n-6 PUFA may protect against the development of allergic disease early in life. High n-6 PUFA intake is also associated with an increased asthma risk while n-3 LCPUFA may be protective and reduce symptoms. The quality of the marine oil used has impact on efficacy of allergy prevention and several observations link in particular n-3 LCPUFA DHA to allergy suppression. Randomized controlled trials indicate that optimal timing, duration and dosage of n-3 LC-PUFA is required to exert an allergy protective effect. Supplementation during early pregnancy and lactation has shown promising results regarding allergy prevention. However these findings should be confirmed in a larger cohort. Although clinical trials in asthma patients reveal no consistent clinical benefits of n-3 LCPUFA supplementation on lung function, it can suppress airway inflammation. Future food-pharma approaches may reveal whether adjunct therapy with dietary n-3 LCPUFA can improve allergy prevention or immunotherapy via support of allergen specific oral tolerance induction or contribute to the efficacy of drug therapy for asthma patients.

Formula with long-chain polyunsaturated fatty acids reduces incidence of allergy in early childhood

BACKGROUND

Allergy has sharply increased in affluent Western countries in the last 30 years. N-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs) may protect the immune system against development of allergy.

METHODS

We prospectively categorized illnesses by body system in a subset of 91 children from the Kansas City cohort of the DIAMOND (DHA Intake and Measurement of Neural Development) study who had yearly medical records through 4 years of age. As infants, they were fed either a control formula without LCPUFA (n = 19) or one of three formulas with LCPUFA from docosahexaenoic acid (DHA) and arachidonic acid (ARA) (n = 72).

RESULTS

Allergic illnesses in the first year were lower in the combined LCPUFA group compared to the control. LCPUFAs significantly delayed time to first allergic illness (p = 0.04) and skin allergic illness (p = 0.03) and resulted in a trend to reduced wheeze/asthma (p = 0.1). If the mother had no allergies, LCPUFAs reduced the risk of any allergic diseases (HR = 0.24, 95% CI = 0.1, 0.56, p = 0.0.001) and skin allergic diseases (HR = 0.35, 95% CI = 0.13, 0.93, p = 0.04). In contrast, if the mother had allergies, LCPUFAs reduced wheezing/asthma (HR = 0.26, 95% CI = 0.07, 0.9, p = 0.02).

CONCLUSIONS

LCPUFA supplementation during infancy reduced the risk of skin and respiratory allergic diseases in childhood with effects influenced by maternal allergies.

Maternal nutrition during pregnancy and risk of asthma, wheeze, and atopic diseases during childhood: a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies suggest a relationship between maternal nutrition during pregnancy and the occurrence of asthma and atopic conditions during childhood. However, individual study results are conflicting. The objective of this meta-analysis was to critically examine the current evidence for an association between nutrition (dietary patterns, food groups, vitamins, or oligo-elements) ingestion during pregnancy and asthma, wheeze, or atopic conditions in childhood.

METHODS

The inclusion criteria were as follows: (i) systematic recording of diet during the gestational period and (ii) documentation of asthma, wheezing, eczema, or other atopic disease in the offspring. The primary outcomes were prevalence of asthma or wheeze among the offspring during childhood; and secondary outcomes were prevalence of eczema, allergic rhinitis, or other atopic conditions.

RESULTS

We found 120 titles, abstracts, and citations, and 32 studies (29 cohorts) were included in this analysis. Data on vitamins, oligo-elements, food groups, and dietary patterns during pregnancy were collected. A meta-analysis revealed that higher maternal intake of vitamin D [odds ratio (OR) = 0.58, 95% confidence interval (CI) = 0.38-0.88], vitamin E (OR = 0.6, 95% CI = 0.46-0.78), and zinc (OR = 0.62, 95% CI = 0.40-0.97) was associated with lower odds of wheeze during childhood. However, none of these or other nutrients was consistently associated with asthma per se or other atopic conditions.

CONCLUSIONS

Current evidence suggests a protective effect of maternal intake of each of three vitamins or nutrients (vitamin D, vitamin E, and zinc) against childhood wheeze but is inconclusive for an effect on asthma or other atopic conditions.

Food Allergy in childhood: phenotypes, prevention and treatment

The prevalence of food allergy in childhood increased in the last decades, especially in Westernized countries where this phenomenon has been indicated as a second wave of the allergic epidemic. In parallel, scientific interest also increased with the effort to explain the reasons of this sudden rise and to identify potential protective and risk factors. A great attention has been focused on early exposures to allergenic foods, as well as on other nutritional factors or supplements that may influence the immune system in a positive direction. Both interventions on maternal diet before birth or during breastfeeding and then directly on infant nutrition have been investigated. Furthermore, the natural history of food allergy also seems to be changing over time; IgE-mediated cow's milk allergy and egg allergy seem to be more frequently a persistent rather than a transient disease in childhood, as described in the last years. Food avoidance and the emergency drugs in case of an adverse event, such as epinephrine self-injector, are currently the first-line treatment in patients with food allergies, with a resulting impairment in the quality of life and social behaviour. During the last decade, oral immunotherapy emerged as an optional treatment with remarkable results, offering a novel perspective in the treatment for and management of food allergy.