Fish intake during pregnancy or infancy and allergic outcomes in children: A systematic review and meta-analysis

Maternal diet quality with child allergic and respiratory multimorbidity in the Elfe birth cohort

Evidence linking maternal diet during pregnancy to allergic or respiratory diseases in children remains sparse, and outcomes were mainly studied separately. We aim to investigate these associations by considering clusters of allergic and respiratory multimorbidity among 9679 mother-child pairs from the Elfe birth cohort. Maternal diet quality was evaluated using a food-based score (Diet Quality score), a nutrient-based score (PANDiet score) and food group intakes. Adjusted multinomial logistic regressions on allergic and respiratory multimorbidity clusters up to 5.5 years were performed. Child allergic and respiratory diseases were described through five clusters: "asymptomatic" (43%, reference), "early wheeze without asthma" (34%), "asthma only" (7%), "allergies without asthma" (7%), "multi-allergic" (9%). A higher PANDiet score and an increased legume consumption were associated with a reduced risk of belonging to the "early wheeze without asthma" cluster. A U-shaped relationship was observed between maternal fish consumption and the "allergies without asthma" cluster. To conclude, adequate nutrient intake during pregnancy was weakly associated with a lower risk of "early wheeze without asthma" in children. No association was found with food groups, considered jointly or separately, except for legumes and fish, suggesting that maternal adherence to nutritional guidelines might be beneficial for allergic and respiratory diseases prevention.

Infantile allergic diseases: a cohort study prenatal fish intake and mercury exposure context

BACKGROUND

Allergic diseases (ADs) have been increasingly reported in infants and children over the last decade. Diet, especially the inclusion of fish intake, may help to lower the risk of ADs. However, fish also, can bioaccumulate environmental contaminants such as mercury. Hence, our study aims to determine what effects the type and frequency of fish intake have on ADs in six-month-old infants, independently and jointly with mercury exposure.

METHODS

This study is part of the prospective birth cohort: Mothers and Children's Environmental Health (MOCEH) study in South Korea. Data was collected on prenatal fish intake, prenatal mercury concentration and ADs for infants aged six months for 590 eligible mother-infant pairs. Logistic regression analysis was conducted to evaluate the risk of prenatal fish intake and mercury concentration on ADs in infants. Finally, interaction between fish intake and mercury concentration affecting ADs in infants was evaluated. Hazard ratios of prenatal fish intake on ADs in 6 month old infants were calculated by prenatal mercury exposure.

RESULTS

Logistic regression analysis showed that white fish (OR: 0.53; 95% CI 0.30-0.94; P < 0.05) intake frequency, once a week significantly decreased the risk of ADs in infants. Stratification analysis showed that consuming white fish once a week significantly reduced the hazard of ADs (HR: 0.44; 95% CI 0.21-0.92; P < 0.05) in infants in the high-mercury (≥ 50th percentile) exposure group.

CONCLUSION

The result indicates that prenatal white fish intake at least once a week reduces the risk of ADs in infants, especially in the group with high prenatal mercury exposure.

Early-life risk factors for food allergy: Dietary and environmental factors revisited

There appears a steep increase in the prevalence of food allergy worldwide in the past few decades. It is believed that, rather than genetic factors, the recently altered dietary and environmental factors are the driving forces behind the rapid increase of this disease. Accumulating evidence has implied that external exposures that occurred in prenatal and postnatal periods could affect the development of oral tolerance in later life. Understanding the potential risk factors for food allergy would greatly benefit the progress of intervention and therapy. In this review, we present updated knowledge on the dietary and environmental risk factors in early life that have been shown to impact the development of food allergy. These predominantly include dietary habits, microbial exposures, allergen exposure routes, environmental pollutants, and so on. The key evidence, conflicts, and potential research topics of each theory are discussed, and associated interventional strategies to prevent the disease development and ameliorate treatment burden are included. Accumulating evidence has supported the causative role of certain dietary and environmental factors in the establishment of oral tolerance in early life, especially the time of introducing allergenic foods, skin barrier function, and microbial exposures. In addition to certain immunomodulatory factors, increasing interest is raised toward modern dietary patterns, where adequately powered studies are required to identify contributions of those modifiable risk factors. This review broadens our understanding of the connections between diet, environment, and early-life immunity, thus benefiting the progress of intervention and therapy of food allergy.

Environmental Risk Factors, Protective Factors, and Biomarkers for Allergic Rhinitis: A Systematic Umbrella Review of the Evidence

Many potential environmental risk factors, protective factors, and biomarkers of AR have been published, but so far, the strength and consistency of their evidence are unclear. We conducted a comprehensive review of environmental risk, protective factors, and biomarkers for AR to establish the evidence hierarchy. We systematically searched Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to December 31, 2022. We calculated summary effect estimate (odds ratio (OR), relative risk (RR), hazard ratio (HR), and standardized mean difference (SMD)), 95% confidence interval, random effects p value, I2 statistic, 95% prediction interval, small study effects, and excess significance biases, and stratification of the level of evidence. Methodological quality was assessed by AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). We retrieved 4478 articles, of which 43 met the inclusion criteria. The 43 eligible articles identified 31 potential environmental risk factors (10,806,206 total population, two study not reported), 11 potential environmental protective factors (823,883 total population), and 34 potential biomarkers (158,716 total population) for meta-analyses. The credibility of evidence was convincing (class I) for tic disorders (OR = 2.89, 95% CI 2.11-3.95); and highly suggestive (class II) for early-life antibiotic use (OR = 3.73, 95% CI 3.06-4.55), exposure to indoor dampness (OR = 1.49, 95% CI 1.27-1.75), acetaminophen exposure (OR = 1.54, 95% CI 1.41-1.69), childhood acid suppressant use (OR = 1.40, 95% CI 1.23-1.59), exposure to indoor mold (OR = 1.66, 95% CI 1.26-2.18), coronavirus disease 2019 (OR = 0.11, 95% CI 0.06-0.22), and prolonged breastfeeding (OR = 0.72, 95% CI 0.65-0.79). This study is registered in PROSPERO (CRD42022384320).

Vitamin D and Omega-3 (Fatty Acid) Supplementation in Pregnancy for the Primary Prevention of Food Allergy in Children-Literature Review

During the last decades the prevalence of food allergy (FA), an adverse immune response to a specific food antigen, has risen, with negative effects on the quality of life (QoL) of many children and their families. The pathogenesis of FA is complex, involving both genetic and environmental factors. SPINK5, STAT6, HLA and FOXP3 are some of the genes that are reported to be implicated in FA development. Regarding environmental factors, particular interest has been focused on modification of the dietary habits of pregnant women for the primary prevention of FA. Specifically, Vitamin D and omega-3 (Ω-3) fatty acid supplementation during pregnancy may influence the development of FA in the offspring. Vitamin D is a hormone with various actions, including mediation of the immune system, reducing the production of inflammatory cytokines and promoting tolerance. Vitamin D deficiency in pregnancy suppresses T-regulatory cells in the fetus, and Vitamin D supplementation might protect against FA development. Dietary Ω-3 fatty acids are found mainly in fish and vegetable oils. They are beneficial for human health, playing a role in the immune system as anti-inflammatory agents, and providing cell membrane stabilization with inhibition of antigen presentation. It is documented that maternal supplementation with Ω-3 during pregnancy may protect from allergic sensitization in the children. The aim of this literature review was to explore the potential preventive role of maternal supplementation during pregnancy with Vitamin D and Ω-3 in the development of FA in the offspring. With the prevalence of FA rising, all the possible protective mechanisms and measures for FA prevention need to be explored, starting with those that can be modified.

Assessing the Anti-Inflammatory Effects of an Orally Dosed Enzymatically Liberated Fish Oil in a House Dust Model of Allergic Asthma

Eosinophils are a major driver of inflammation in a number of human diseases, including asthma. Biologic therapies targeting IL-5 have enabled better control of severe eosinophilic asthma, but no such advances have been made for enhancing the control of moderate asthma. However, a number of moderate asthma sufferers remain troubled by unresolved symptoms, treatment side effects, or both. OmeGo, an enzymatically liberated fish oil, has demonstrated antioxidant and anti-inflammatory properties including the reduction of eosinophilia. A house dust mite model of induced asthma in mice was utilized in this study, and OmeGo showed a significant reduction in eosinophilic lung and systemic inflammation and reduced lung remodelling compared to cod liver oil. The CRTH2 antagonist fevipiprant showed an anti-inflammatory profile similar to that of OmeGo. OmeGo has the potential to be a pragmatic, cost-effective co-treatment for less severe forms of eosinophilic asthma. Proof-of-concept studies are planned.

Aquaculture omics: An update on the current status of research and data analysis

Aquaculture is the fast-growing agricultural sector and has the ability to meet the growing demand for protein nutritional security for future population. In future aquaculture is going to be the major source of fish proteins as capture fisheries reached at its maximum. However, several challenges need to overcome such as lack of genetically improved strains/varieties, lack of species-specific feed/functional feed, round the year availability of quality fish seed, pollution of ecosystems and increased frequencies of disease occurrence etc. In recent years, the continuous development of high throughput sequencing technology has revolutionized the biological sciences and provided necessary tools. Application of 'omics' in aquaculture research have been successfully used to resolve several productive and reproductive issues and thus ensure its sustainability and profitability. To date, high quality draft genomes of over fifty fish species have been generated and successfully used to develop large number of single nucleotide polymorphism markers (SNPs), marker panels and other genomic resources etc in several aquaculture species. Similarly, transcriptome profiling and miRNAs analysis have been used in aquaculture research to identify key transcripts and expression analysis of candidate genes/miRNAs involved in reproduction, immunity, growth, development, stress toxicology and disease. Metagenome analysis emerged as a promising scientific tool to analyze the complex genomes contained within microbial communities. Metagenomics has been successfully used in the aquaculture sector to identify novel and potential pathogens, antibiotic resistance genes, microbial roles in microcosms, microbial communities forming biofloc, probiotics etc. In the current review, we discussed application of high-throughput technologies (NGS) in the aquaculture sector.

Association of Maternal Erythrocyte PUFA during Pregnancy with Offspring Allergy in the Chinese Population

Findings on prenatal polyunsaturated fatty acids (PUFA) and offspring allergies have been inconsistent, and the majority of studies have focused on Western populations. This study aimed to investigate the associations between maternal erythrocyte PUFA and offspring allergies in the first 2 years in the Chinese population. We included 573 mother–infant pairs from a birth cohort. Based on the outpatient medical records, we identified the diagnosis and time of offspring allergic disease onset. We measured erythrocyte fatty acids by gas chromatography. Associations were examined using Cox regression. We found that higher maternal total PUFA levels (HR = 0.80; 95% CI: 0.68, 0.94), especially of arachidonic acid (AA) (HR = 0.79; 95% CI: 0.65, 0.97) and n-3 PUFA (HR = 0.77; 95% CI: 0.62, 0.97), were associated with reduced risk of offspring allergies. Similar results were found for eczema. Compared with children without a maternal allergy history, the associations of total PUFA (p = 0.028) and n-6 PUFA (p = 0.013) with offspring allergies were stronger in those with a maternal allergy history. Maternal erythrocyte total PUFA, especially AA, and n-3 PUFA were inversely associated with offspring allergies within 2 years of age. There was a significant interaction between maternal allergy history and maternal PUFA in offspring allergies.

Dietary strategies for the prevention of asthma in children

PURPOSE OF REVIEW

This review summarizes information relating to dietary intake during pregnancy, lactation and early life that may prevent childhood asthma. This review also summarizes how future studies may be improved.

RECENT FINDINGS

Recent findings from observational studies suggest that eating according to certain dietary patterns during pregnancy, such as the dietary inflammatory index, Mediterranean diet and Maternal diet index, may reduce asthma and or wheeze in the child. Vitamin D supplementation with higher doses than recommended during pregnancy may be associated with reduced early transient childhood wheezing in the offspring. Higher levels of omega-3 fatty acids in breast milk may be protective against childhood asthma. Breastfeeding infants has been shown to offer many benefits to mother and child but a direct relationship between breastfeeding and the development of asthma has not been established. During childhood, infants and children may need to reduce their intake of advanced glycation end products, increase their food intake according to the traditional Mediterranean diet and increase the diversity of foods eaten.

SUMMARY

Current evidence provides limited suggestions regarding dietary changes for preventing early transient childhood wheezing. In order to harmonize methods for future data collection and reporting, it is important to harmonize relevant definitions and other important factors. The aim of the considerations described here is to enable a better comparison of future studies and provide better guidance to patients and families.

Food Protein-Induced Allergic Proctocolitis: The Effect of Maternal Diet During Pregnancy and Breastfeeding in a Mediterranean Population

Background

The aim of the current investigation was to explore the association of food protein-induced allergic proctocolitis (FPIAP) with the maternal diet during pregnancy and breastfeeding in Greek infants.

Methods

A multicenter retrospective case-control study was conducted in 6 regions in Greece, with 96 mothers of infants with and 141 mothers of infants without a history of FPIAP. Maternal dietary habits during pregnancy and breastfeeding were evaluated with the following validated questionnaires: (a) The Mediterranean Diet Score and (b) The Mediterranean Oriented Culture-Specific Semi-Quantitative Food Frequency Questionnaire.

Results

FPIAP was associated with cow's milk (83.6%), egg (7.3%), wheat (6.4%), and beef (6.4%) in the maternal diet. Adherence to Mediterranean Diet was similar among the mothers. Mothers of FPIAP infants consumed more vegetables. Elastic net prediction models showed that, in this Mediterranean population, increased consumption during pregnancy and lactation of common allergens, whole grain products, homemade food, fish and shellfish, and fruits was associated with a decreased risk of FPIAP. Conversely, a high intake of vegetables, sugar and total fat, and non-stick/grilled cooking, were associated with increased risk of FPIAP, as was a high intake of salt and white flour during lactation only.

Conclusions

Components of a maternal Mediterranean Diet may protect against FPIAP when traditional cooking methods are adopted and fish, fruit, and whole wheat products are consumed frequently during pregnancy and breastfeeding.

Primary Prevention of Pediatric Asthma through Nutritional Interventions

Asthma is the most common chronic non-communicable disease in children, the pathogenesis of which involves several factors. The increasing burden of asthma worldwide has emphasized the need to identify the modifiable factors associated with the development of the disease. Recent research has focused on the relationship between dietary factors during the first 1000 days of life (including pregnancy)—when the immune system is particularly vulnerable to exogenous interferences—and allergic outcomes in children. Specific nutrients have been analyzed as potential targets for the prevention of childhood wheeze and asthma. Recent randomized controlled trials show that vitamin D supplementation during pregnancy, using higher doses than currently recommended, may be protective against early childhood wheezing but not school-age asthma. Omega-3 fatty acid supplementation during pregnancy and infancy may be associated with a reduced risk of childhood wheeze, although the evidence is conflicting. Data from observational studies suggest that some dietary patterns during pregnancy and infancy might also influence the risk of childhood asthma. However, the quality of the available evidence is insufficient to allow recommendations regarding dietary changes for the prevention of pediatric asthma. This review outlines the available high-quality evidence on the role of prenatal and perinatal nutritional interventions for the primary prevention of asthma in children and attempts to address unmet areas for future research in pediatric asthma prevention.

The causal association of polyunsaturated fatty acids with allergic disease: A two-sample Mendelian randomization study

Objectives

Previous studies have reported a potential association of polyunsaturated fatty acids (PUFAs) levels with allergic disease risk and the possible benefit of PUFAs supplementation on allergic disease prevention. This study was performed to estimate the genetic association between PUFAs and allergic diseases using the method of both univariable and multivariable two-sample Mendelian randomization (MR).

Methods

As indicators of the PUFAs levels, we included the omega-3, omega-6, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), linoleic acid (LA), and the ratio of omega-6 to omega-3 (omega-6:3). Summarized statistics of genome-wide association studies (GWASs) for these PUFAs were obtained from the United Kingdom Biobank and the Twins United Kingdom cohort. Genetic data relating to allergic diseases, including atopic dermatitis (AD), allergic rhinitis (AR), allergic conjunctivitis (AC), allergic urticaria (AU) and asthma, were accessed from the FinnGen biobank analysis. Odds ratios and 95% CIs were used to express the impact.

Results

The MR results denoted a genetic association between the genetically determined increase in omega-3 levels and the decreased risk of some allergic diseases including AD (OR: 0.863; 95% CI: 0.785 to 0.949; p = 3.86E-03), AC (OR:0.720; 95% CI: 0.547 to 0.947; p = 1.87E-02) and AU (OR:0.821; 95% CI: 0.684 to 0.985; p = 3.42E-02), while omega-6 and DHA level was only found to have negatively correlation with risk of AC with ORs of 0.655 (95% CI: 0.445 to 0.964; p = 3.18E-02) and 0.671 (95% CI 0.490 to 0.918; p = 1.25E-02), respectively. Omega-6:3 were causally significantly associated with the increased risk of AD (OR:1.171; 95% CI: 1.045 to 1.312; p = 6.46E-03) and AC (IVW: OR:1.341; 95% CI: 1.032 to 1.743; p = 2.83E-02). After adjustment of age, economic level, BMI, smoking and alcohol behaviors in the multivariable MR analysis, a direct causal protective effect of omega-3 on AD and AC, as well as a direct causal association between DHA and AD were observed. Omega-6:3 was also found to be directly associated with an increased risk of AD and AC. No association was found of EPA or LA with allergic diseases.

Conclusion

Higher PUFA concentrations (omega-3, omega-6, DHA) and lower omega-6:3 ratios were genetically associated with a lower risk of some allergic diseases.

Influence of Maternal Fish Oil Supplementation on the Risk of Asthma or Wheeze in Children: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous studies evaluating the influences of maternal fish oil supplementation on the risk of asthma or wheeze in children showed inconsistent results. We performed a meta-analysis or randomized controlled trials (RCTs) to systematically evaluate the efficacy of maternal fish oil supplementation for asthma or wheeze.

METHODS

Relevant RCTs were obtained by search of PubMed, Embase, and Cochrane's Library databases. A random-effects model incorporating the potential publication bias was used to pool the results.

RESULTS

Ten RCTs with 3,676 infants were included. Compared to control, maternal supplementation with fish oil was not associated with a reduced risk of asthma or wheeze [odds ratio (OR): 0.91, 95% confidence interval (CI): 0.72-1.14, P = 0.40] with mild heterogeneity (I ² = 28%). Subgroup analyses showed that maternal fish oil supplementation significantly reduced the risk of asthma (OR: 0.56, 95% CI: 0.35-0.91, P = 0.02; I ² = 0%), but not the risk of wheeze (OR: 1.12, 95% CI: 0.90-1.41, P = 0.32; I ² = 0%). In addition, maternal fish oil supplementation was associated with reduced risk of asthma or wheeze in high-dose studies (≥1,200 mg/d, OR: 0.65, 95% CI: 0.48-0.87, P = 0.003; I ² = 0%), but not in low-dose studies (<1,200 mg/d, OR: 1.10, 95% CI: 0.88-1.38, P = 0.39; I ² = 0%, P for subgroup difference = 0.005). Study characteristics such as the risk of the infants, timing of supplementation, and follow-up duration did not significantly affect the results.

CONCLUSIONS

Maternal fish oil supplementation may reduce the risk of clinically diagnosed asthma in children, particularly with high-dose fish oil.

Potential Role of Omega-3 Polyunsaturated Fatty Acids in Pediatric Food Allergy

Polyunsaturated fatty acids (PUFAs) are involved both in immune system regulation and inflammation. In particular, within the PUFAs category, omega-3 (ω-3) may reduce inflammation, whereas omega-6 (ω-6) PUFAs are generally considered to have a proinflammatory effect. Recent evidence highlights an imbalance in the ω-3:ω-6 ratio with an increased intake of ω-6, as a consequence of the shift towards a westernized diet. In critical age groups such as infants, toddlers and young children, as well as pregnant and lactating women or fish allergic patients, ω-3 intake may be inadequate. This review aims to discuss the potential beneficial effects of PUFAs on pediatric food allergy prevention and treatment, both at prenatal and postnatal ages. Data from preclinical studies with PUFAs supplementation show encouraging effects in suppressing allergic response. Clinical studies results are still conflicting about the best timing and dosages of supplementation and which individuals are most likely to benefit; therefore, it is still not possible to draw firm conclusions. With regard to food-allergic children, it is still debated whether PUFAs could slow disease progression or not, since consistent data are lacking. In conclusion, more data on the effects of ω-3 PUFAs supplementation alone or in combination with other nutrients are warranted, both in the general and food allergic population.

What are the highest yielding search strategy terms for systematic reviews in atopic dermatitis? A systematic review

The impact of search strategies on systematic reviews (SR) of atopic dermatitis (AD) is unknown. The purpose of this review was to evaluate search strategies used in SR of AD and their impact on the frequency of manuscripts identified. MEDLINE and EMBASE were searched for SR related to AD. Simulations were performed by running combinations of search terms in MEDLINE and EMBASE. Overall, 250 SR met inclusion criteria, of which 225 specified search strategies. SR using 5-6 terms (20.0% to 12.1%) or ≥ 7 (40.0% to 18.8%) terms decreased, whereas SR using 3-4 terms numerically increased (18.8% to 30.2%) and 1-2 terms remained similar (37.5% to 38.9%) from 1999-2009 to 2015-2019. The most commonly searched terms were "atopic dermatitis" (n = 166), followed by "eczema" (n = 156), "dermatitis atopic'" (n = 81), "atopic eczema" (n = 74), "neurodermatitis" (n = 59), "Besniers prurigo" (n = 29), "infantile eczema" (n = 27), and "childhood eczema" (n = 19). Simulations revealed that "eczema" and "atopic dermatitis" yielded the most hits. The number of search terms that maximized hits in MEDLINE and EMBASE was 5 and 4, respectively. Search strategies for AD were heterogeneous, with high proportions of search strategies providing few search hits. Future studies should use standardized and optimized search terms.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

Intake of n-3 polyunsaturated fatty acids in childhood, FADS genotype and incident asthma

Longitudinal evidence on the relation between dietary intake of n-3 (ω-3) very-long-chain polyunsaturated fatty acids, i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in mid-childhood and asthma risk is scarce. We aimed to investigate whether a higher intake of EPA and DHA from fish in childhood is associated with a lower risk of incident asthma.In the Avon Longitudinal Study of Parents and Children, dietary intakes of EPA and DHA from fish were estimated by food frequency questionnaire at 7 years of age. We used logistic regression, controlling for confounders, to analyse associations between intake of EPA and DHA (quartiles) and incidence of doctor-diagnosed asthma at age 11 or 14 years, and explored potential effect modification by a fatty acid desaturase (FADS) polymorphism (rs1535). Replication was sought in the Swedish BAMSE birth cohort.There was no evidence of association between intake of EPA plus DHA from fish and incident asthma overall (n=4543). However, when stratified by FADS genotype, the odds ratio comparing the top versus bottom quartile among the 2025 minor G allele carriers was 0.49 (95% CI 0.31-0.79; ptrend=0.006), but no inverse association was observed in the homozygous major A allele group (OR 1.43, 95% CI 0.83-2.46; ptrend=0.19) (pinteraction=0.006). This gene-nutrient interaction on incident asthma was replicated in BAMSE.In children with a common FADS variant, higher intake of EPA and DHA from fish in childhood was strongly associated with a lower risk of incident asthma up to mid-adolescence.

The evidence for interventions in early childhood allergy prevention - towards a living systematic review: protocol

Background: Research in early childhood allergy prevention (ECAP) is flourishing and new intervention strategies have proven to be promising. Due to the dynamic nature of ECAP, gaps between what is known and how guidelines inform practice are likely. A living systematic review (LSR) can narrow this gap by incorporating new evidence as it becomes available. No efficacy comparisons across various ECAP interventions for similar outcomes have been carried out. Networks of randomised clinical trials can be evaluated in the context of a network meta-analysis (NMA). We aim to establish a LSR on the efficacy and safety of any intervention investigated in randomised controlled trials (RCT) to prevent the occurrence of allergic sensitisation (AS), symptoms or diagnoses of allergic diseases in infancy and early childhood (0-3 years). Methods: A baseline SR will synthesise the evidence from existing SRs of RCTs as well as RCTs not yet considered in these. After completion of the baseline SR we propose to conduct a LSR. Using this methodology, we aim to undertake constant evidence surveillance, three-monthly search updates, and review updates every three months, should new evidence emerge. Conclusions: The ECAP evidence landscape has undergone dramatic transformations and this process is likely to continue. As a response to this, a LSR offers the potential to allow more timely synthesis of new evidence as it emerges. Long gaps between updates of SRs makes it harder for guidelines and recommendations to be up to date. Users of information, such as parents, may be confused if they encounter new evidence that is not part of a trusted guideline. A LSR approach allows us to continuously search the literature and update the evidence-base of existing ECAP interventions resulting in a decreased timespan from evidence accrual to informing clinical practice.

Lipid Nutrition in Asthma

Asthma is a heterogeneous pulmonary disease that has constantly increased in prevalence over the past several decades. Primary symptoms include airway constriction, airway hyperresponsiveness, and airway remodeling with additional symptoms such as shortness of breath, wheezing, and difficulty breathing. Allergic asthma involves chronic inflammation of the lungs, and the rise in its yearly diagnosis is potentially associated with the increased global consumption of foods similar to the western diet. Thus, there is growing interest into the link between diet and asthma symptoms, with mounting evidence for an important modulatory role for dietary lipids. Lipids can act as biological mediators in both a proinflammatory and proresolution capacity. Fatty acids play key roles in signaling and in the production of mediators in the allergic and inflammatory pathways. The western diet leads to a disproportionate ω-6:ω-3 ratio, with drastically increased ω-6 levels. To counteract this, consumption of fish and fish oil and the use of dietary oils with anti-inflammatory properties such as olive and sesame oil can increase ω-3 and decrease ω-6 levels. Increasing vitamin intake, lowering LDL cholesterol levels, and limiting consumption of oxidized lipids can help reduce the risk of asthma and the exacerbation of asthmatic symptoms. These dietary changes can be achieved by increasing intake of fruits, vegetables, nuts, oily fish, seeds, animal-related foods (eggs, liver), cheeses, grains, oats, and seeds, and decreasing consumption of fried foods (especially fried in reused oils), fast foods, and heavily processed foods.

Fish consumption during pregnancy and risk of allergic diseases in the offspring: A systematic review and meta-analysis

Although several studies have reported the beneficial effects of maternal fish consumption on allergy diseases in the offspring, the findings are conflicting. We summarized earlier data on the association between maternal fish intake and risk of allergy diseases in the offspring through a meta-analysis. A systematic literature search of relevant reports published in Medline/PubMed, ISI web of Science, EMBASE, SCOPUS and Google Scholar prior to February 2020 was conducted. All observational studies (cross-sectional, case-control or cohort) that examined the relationship between intake of maternal fish and risk of allergy diseases in the offspring were considered. Duplicate and non-related studies were excluded. In total, 31 studies on maternal fish consumption and risk of allergic diseases in the offspring were included. Greater maternal fish intake was associated with a reduced risk of wheeze (Pooled effect size: 0.97; 95% CI: 0.96-0.99) and food allergy (0.75; 95% CI: 0.64-0.88). Maternal fish consumption was not associated with risk of asthma (pooled effect size: 0.99; 95% CI: 0.89, 1.11), eczema (pooled effect size: 0.93; 95% CI: 0.84, 1.03), allergic rhinitis (pooled effect size: 0.91; 95% CI: 0.75, 1.09), and inhalant allergy (pooled effect size: 0.86; 95% CI: 0.66, 1.13). In non-linear dose-response meta-analysis, increased intake of fish during pregnancy (at the level of 50 to 200 grams per week) was associated with a reduced risk of eczema (P non-linearity = 0.042). Meta-regression of included studies revealed an inverse linear association between maternal fish intake and risk of eczema; such that every additional 30-gram per week consumption of fish during pregnancy was associated with a 4% reduced risk of eczema. We found that fish intake during pregnancy was associated with a lower risk of wheeze, eczema and food allergy in children. No significant association was seen between maternal fish consumption and risk of offspring's asthma, allergic rhinitis, and inhalant allergy.

Maternal Dietary Protein Patterns During Pregnancy and the Risk of Infant Eczema: A Cohort Study

Background: Previous studies have suggested that maternal dietary protein was associated with allergic diseases in offspring, but few studies have evaluated the influence of dietary protein patterns. This study aimed to explore the prospective association between maternal dietary protein patterns during pregnancy and the risk of infant eczema.

Methods: A total of 713 mother-child pairs from a prospective cohort in Guangzhou, China were recruited. Maternal dietary protein was estimated using a validated face-to-face food frequency questionnaire at 20–28 weeks' gestation from 2017 to 2018. Dietary protein patterns were calculated based on the sources of protein. The data of infant eczema was assessed at 6 months of age using the symptom questionnaire of eczema. Logistic regression was carried out to examine the associations between maternal dietary protein patterns and infant eczema.

Results: The cumulative incidence of infant eczema at 6 months of age was 51.19%. Mothers of infants with eczema consumed more protein from poultry source during pregnancy than mothers of infants without eczema, while no statistical differences were observed in maternal intakes of protein from cereals and tubers, vegetables, fruits, red meat, fish and seafood, eggs, dairy, soybean, and nuts and seeds. Four dietary protein patterns were identified and termed poultry, plant, dairy and eggs, and red meat and fish. The cumulative incidence of eczema was 61.2, 45.8, 48.0, 51.4% for these four patterns, respectively. Compared to the poultry dietary pattern, the plant pattern and the dairy and eggs pattern were associated with a reduced risk of infant eczema, and the adjusted odds ratios (95% confidence interval) were 0.572 (0.330–0.992), 0.478 (0.274–0.837), respectively. No such association was observed for the red meat and fish dietary protein pattern.

Conclusion: This is the first study that focused on the association between maternal dietary protein during pregnancy from a whole-diet perspective and infant eczema. Compared with the poultry dietary protein pattern, the maternal plant pattern and the dairy and eggs pattern during pregnancy were associated with a reduced risk of infant eczema.

Hydrolysed formula, delayed food introduction and fatty acids for atopic dermatitis prevention in infancy

AIM

The role of nutrition in preventing atopic diseases including atopic dermatitis has recently gained interest in the medical community. Caregivers of infants and children at an increased risk for developing atopic dermatitis often employ exclusion diets or other measures in hopes of preventing the development of this burdensome disease. This paper reviews the current literature in regard to the role of preventative dietary measures in the context of atopic dermatitis, with a special focus on the topics of hydrolysed formula, early vs. delayed introduction of certain foods and fatty acid supplementation.

METHODS

Literature pertaining to preventative dietary measures for infants at risk for atopic dermatitis was reviewed.

RESULTS

Analysis of the literature suggests that hydrolysed formula should not be routinely offered to infants for prevention of atopic dermatitis. Formulas utilised should contain concentrations of polyunsaturated fatty acids similar to that in breast milk. Finally, infant caregivers should not delay or restrict introduction of food, which can be more harmful than helpful to the patient.

CONCLUSION

Recommendations to caretakers providing for infants at risk for atopic dermatitis should include infant consumption of breast milk and avoid delayed introduction of foods.

[Diet and asthma: Better eating for better breathing?]

Inhaled therapies are the cornerstone of asthma treatment. However, according to national and international guidelines, non-pharmacological interventions should not be neglected in asthma. It has been demonstrated that a healthy diet is beneficial to general health. Recently, the effect of diet on asthma has been highlighted in many studies. Two diets have been particularly studied: the Mediterranean diet (high in fruits and vegetables and low in fat) and the Western diet (high in saturated fat and low in fruits and vegetables). A beneficial effect of the Mediterranean diet and deleterious effect of the Western diet on the development or control of asthma has been shown in some studies even after adjustment for overweight. Study findings have not been unanimous, probably related to the complexity of conducting studies on a diet that may change from day to day for any individual subject. In addition, the effect of physical exercise, which is known to be beneficial in asthma, is rarely taken into account in these studies. However, studies on diet are becoming more complex with the use of specific dietary indices, which should bring interesting data in the future.

Allergy Prevention: An Overview of Current Evidence

Background: There has been a rapid rise in allergic disorders across the globe. This has increased research into the determinants of allergy development, to identify factors that may be manipulated to mitigate risk. An opportune window in immunological development appears to exist in early life whereby certain exposures may promote or prevent the development of an allergic disposition. Furthermore, factors that affect the composition and diversity of the microbiome in early life have been explored. In this review, we discuss current literature and recommendations relating to exposures that may prevent allergy development or promote tolerance. Risk factors and recommendations: Delivery by caesarean section, omission of breastfeeding, vitamin D insufficiency, and environmental exposures, such as cigarette smoke exposure, all increase the risk of an allergic predisposition. Dietary diversity during pregnancy, lactation, and in infancy is protective. Breastfeeding for at least 4 months reduces the risk of eczema. Recommendations for food-allergen exposure has shifted from delayed introduction to early introduction as a tolerance-inducing strategy. Supplements such as probiotics and vitamins during pregnancy and infancy have yet to produce conclusive results for allergy prevention. Emollient use in infancy has not been shown to be protective against eczema or food allergy.

Sensitization to Local Seafood Allergens in Adult Patients with Atopic Dermatitis in Malaysia

BACKGROUND

Seafood is an important source of nutrition in Asia. However, it was believed to cause or aggravate atopic dermatitis (AD).

OBJECTIVES

We aim to determine relevant seafood sensitization among adults with AD and investigate cross-sensitization to aeroallergens.

METHODS

One hundred thirty-two adults with AD who were subjected to skin prick test (SPT) with 7 common local seafood allergens (anchovy, tuna, mackerel, squid, giant freshwater prawn, shrimp, and crab), house dust mites (HDMs), and cockroach were analyzed retrospectively.

RESULTS

The median age of the study subjects was 32 years (range 17-77 years) with a male to female ratio of 1:3. The mean duration of AD was 16 years. Eighty-two patients (62.2%) had other atopic conditions. Using SCORAD, 44.7% had mild, 42.4% moderate, and 12.9% severe disease. Eighty-six patients (65.2%) self-reported to have seafood allergy, with the main symptoms of transient pruritus and erythema within 2 h of ingestion. SPT revealed 51.5% of the patients were sensitized to at least 1 of the 7 seafood allergens. The relevant sensitization rate was 45.1%. Interestingly, 46% of those without a history of seafood allergy developed at least 1 positive reaction in the SPT. Prawn, shrimp, and crab were the 3 most frequently sensitized allergens. Nearly all patients (98.3%) who were sensitized to crustaceans were also sensitized to HDMs and/or cockroach. There was no significant correlation between a positive SPT to seafood with age, age of onset of AD, duration, and severity of AD, and the presence of other atopic diatheses.

CONCLUSION

The relevant sensitization rate of local seafood among adults with AD was 45.1%.

Effect of maternal sleep, physical activity and screen time during pregnancy on the risk of childhood respiratory allergies: a sex-specific study

BACKGROUND

Early life exposure in the uterus had a long-term effect on children's health. As the prevalence of allergies is increasing with a remarkable sex difference, very few studies have traced back to their early origins. We sought to investigate if maternal behavioral exposure, herein sleep, physical activity, and screen time during pregnancy is associated with childhood respiratory allergies. The sex difference would be examined.

METHODS

Six thousand two hundred thirty-six mother-child pairs from Shanghai Children Allergy Study (SCAS) were enrolled, The International Study of Asthma and Allergies in Childhood questionnaire was adopted to evaluate respiratory allergic diseases.

RESULTS

14.6, 16.2, and 21.0% of children had asthma, wheeze, and allergic rhinitis, respectively. Maternal short sleep duration, lack of physical activity, and too much screen exposure during pregnancy could increase the risk of childhood respiratory allergies, however, the significance was found only in males. Moreover, a dose-response trend was clearly shown, any two of the three combined could increase the risk (OR,1.921; 95% CI,1.217-3.033), and the coexistence of all three further amplified the risk (OR,2.412; 95% CI,1.489-3.906). The findings can be verified in allergen test subgroup and each single type of respiratory allergies in most cases.

CONCLUSIONS

Maternal unhealthy behaviors during pregnancy could increase the risk of childhood respiratory allergies with a dose-response pattern. Males were more susceptible to the association. The identification of modifiable maternal risk behaviors lies in the emphasis of intervention in early life to face up increasing childhood allergies.

Nutritional Issues in Food Allergy

Diet and nutrition play an important role in the development and management of food allergy. The diet of expectant mothers can have an effect on their offspring in terms of allergic outcomes. A host of confounding factors may influence this, with a maternal diet rich in fruits and vegetables, fish, vitamin D-rich foods associated with a lower risk of allergic disease in their children. More surprisingly, the consumption of milk and butter has also been shown to have a protective effect, especially in a farm environment. Similarly, the diet of the infant can also be important, not only in terms of breast feeding, but also the timing of the introduction of complementary foods, the diversity of the diet and the effect of individual foods on the development of allergy. One factor which has clearly been shown not to influence the development of food allergy is allergen avoidance by expectant mothers. In the infant diet, the manipulation of the gut microbiome to prevent the development of atopic disease is clearly an area which promises much, although studies have yet to provide a breakthrough in the prevention of atopic dermatitis. More concrete evidence of the value of diet in prevention has come from studies evaluating infant eating patterns which may protect gut health, through the consumption of large amounts of home-processed fruits and vegetables. The consumption of fish during the first year of life has also been shown to be protective. The importance of nutritional issues in children and adults who have a food allergy has become much more accepted in recent years. The primary allergenic foods in infancy and childhood, milk, egg, wheat and soy are also ones which are present in many foods and thus their avoidance can be problematic from a nutritional perspective. Thus, children with a food allergy can have their growth compromised through avoidance, especially pre-diagnosis, when foods may be excluded without any expert nutritional input. The management of a food allergy largely remains the exclusion of the offending food(s), but it is now clear that in doing so, children in particular can be at nutritional risk if insufficient attention is paid to the rest of the diet. Adults with food allergy are often thought not to need nutritional counselling; however, many will exclude a wide range of foods due to anxiety about trace exposure, or similar foods causing reactions. The avoidance of staple foods such as milk and wheat are common, but substitute foods very often do not have comparable nutritional profiles. Adults may also be more susceptible to on-line promotion of extreme nutritional regimes which can be extremely harmful. All food allergic individuals, whatever their age, should have a nutrition review to ensure they are consuming a healthy, balanced diet, and are not avoiding food groups unnecessarily.

Interactions between dietary habits and home environmental exposures on respiratory symptoms in Romanian school children: an analysis of data from the SINPHONIE project

In this study, we investigated the interactions between household pollutants and dietary habits on children's respiratory health. Our cross-sectional study collected self-reported information including health symptoms (allergy-like, asthma-like, and flu-like symptoms), home characteristics, dietary habits, and demographic information from questionnaires administered to parents of 280 school children in Romania. Unconditional logistic regression and stratified analyses were used to assess the interactions between dietary factors and environmental exposures on health symptoms among children, controlling for sociodemographic characteristics and co-exposures. We found that frequency of fruit consumption had significant interaction with residing near heavy traffic on allergy-like symptoms among children (p = 0.036). However, no association was observed by frequency of fruit consumption. Although no significant interaction was observed, we found that students with infrequent fruit consumption and residing near heavy traffic roads had elevated odds of asthma-like (POR 6.37; 95% CI 1.22, 33.29) and flu-like symptoms (POR 3.75; 95% CI 1.12, 11.86) than those who frequently consumed fruits. Likewise, low vegetable consumption was associated with increased asthma-like symptoms (POR 2.93; 95% CI 1.04, 8.24). Increased odds of asthma-like symptoms were observed among school children that resided near heavy traffic roads and frequently consumed milk (POR 2.80; 95% CI 1.24, 6.31) and yoghurt (POR 2.86; 95% CI 1.05, 7.75) compared to those that infrequently consumed dairy. Our findings suggest that frequent fruit and vegetable consumption may mitigate the negative effects of exposure to heavy traffic near dwelling on respiratory symptoms in Romanian children.

Synthesis of anti-allergic drugs

Histamine is formed by the decarboxylation of histidine catalyzed by enzymes. It is an endogenous biologically active substance involved in multiple complex physiological processes as an important chemical transmitter. Histamine receptors have four subtypes, H₁, H₂, H₃ and H₄, all of which are G protein coupling receptors (GPCRs) with different physiological functions. Histamine plays an important role in the pathophysiological mechanism of allergic diseases, and the antagonistic effect of histamine has become an important way to study anti-allergic drugs, wherein the anti-allergic drugs used in clinical practice are mainly H₁ receptor antagonists. Currently, there are many varieties of H₁ receptor antagonists in clinical applications, which can be divided into ethylenediamine antagonists, amino ether antagonists, propylamine antagonists, tricyclic antagonists, piperazine antagonists and piperidine antagonists depending on their chemical structures. This article mainly reviews the research progress of allergic reactions with histamine H₁ receptor antagonists and expounds the important aspects of the design and synthesis of various new compounds.

Histamine is formed by the decarboxylation of histidine catalyzed by enzymes. It is an endogenous biologically active substance involved in multiple complex physiological processes as an important chemical transmitter.

Current Insights on Early Life Nutrition and Prevention of Allergy

The incidence of allergic diseases in childhood appears to have significantly increased over the last decades. Since environmental factors, including diet, have been thought to play a significant role in the development of these diseases, there is great interest in identifying prevention strategies related to early nutritional interventions. Breastfeeding is critical for the immune development of newborns and infants through immune-modulating properties and it impacts the establishment of a healthy gut microbiota. However, the evidence for a protective role of breastfeeding against the development of food allergy in childhood is controversial, and there is little evidence to support the benefits of an antigen avoidance diet during lactation. Although it is not possible to draw a definitive conclusion about the protective role of breast milk against allergic diseases, exclusive breastfeeding is still recommended throughout the first 6 months of life due to associated health benefits. Furthermore, recommendations regarding complementary feeding in infancy have been significantly modified over the last few decades. Several studies have shown that delayed exposure to allergenic foods does not have a role in allergy prevention and recent guidelines recommend against delaying the introduction of complementary foods after 6 months of age, both in high- and low-risk infants. However, trials investigating this dietary approach have reported equivocal results so far. This review summarizes the available high-quality evidence regarding the efficacy of the principal dietary interventions proposed in early life to prevent allergic diseases in children.

Design, synthesis and biological activity of a novel ethylenediamine derivatives as H1 receptor antagonists

In this study, a series of novel ethylenediamine compounds were obtained by structural modification of the lead compounds with thonzylamine, and using the principle of modifying by bioisostere formation and modification with alkyl groups. In vitro assay, the biological activities showed that the target compounds have good properties in inhibiting mast cell degranulation and releasing histamine and β-aminohexidase, such as the compounds 5c, 5g, 5k, 5l and 5o, especially of compound 5k to mast cell degranulation is IC₅₀ = 0.0106 ± 0.001 μmol⋅L^-1, histamine release was IC₅₀ = 0.0192 ± 0.005 μmol⋅L^-1 and β-hexosaminidase release was IC₅₀ = 0.0455 ± 0.002 μmol⋅L^-1in vitro. At the same time, in vivo biological activities assay results showed that have a good Histamie induce bronchospasm effect with relatively long duration and good protective effect in vivo, among which the protective effect of compound 5k was 79.74 ± 0.30%, compounds 5c, 5g, 5k, 5l and 5o could inhibit the capillary permeability of increasing which were caused by histamine.

Dietary Fatty Acids and Host-Microbial Crosstalk in Neonatal Enteric Infection

Human milk is the best nutritional choice for infants. However, in instances where breastfeeding is not possible, infant formulas are used as alternatives. While formula manufacturers attempt to mimic the performance of human breast milk, formula-fed babies consistently have higher incidences of infection from diarrheal diseases than those breastfed. Differences in disease susceptibility, progression and severity can be attributed, in part, to nutritional fatty acid differences between breast milk and formula. Despite advances in our understanding of breast milk properties, formulas still present major differences in their fatty acid composition when compared to human breast milk. In this review, we highlight the role of distinct types of dietary fatty acids in modulating host inflammation, both directly and through the microbiome-immune nexus. We present evidence that dietary fatty acids influence enteric disease susceptibility and therefore, altering the fatty acid composition in formula may be a potential strategy to improve infectious outcomes in formula-fed infants.

Fish Consumption at One Year of Age Reduces the Risk of Eczema, Asthma and Wheeze at Six Years of Age

Background: The role of dietary fish and n-3 polyunsaturated fatty acids (n-PUFAs) in the primary prevention of allergic diseases remains uncertain. The aim of this study was to investigate associations between the consumption of fish and cod liver oil (rich in n-PUFAs) from pregnancy to the first two years of life, and parental reported allergic diseases at six years of age. Methods: We used data from the Prevention of Allergy among Children in Trondheim study and included mother-infant pairs who had submitted questionnaires detailing both maternal or infant diet and allergic disease at six years of age. Results: Eating fish at least once a week at one year of age was associated with a 28%, 40% and 34% reduction in the odds of current eczema, asthma, and wheeze at six years of age, respectively. Cod liver oil consumption at least four times per week at one year of age tended to be associated with a lower risk of allergy-related outcomes at six years. We found no consistent associations between allergy-related outcomes and fish or cod liver oil consumption by mothers. Conclusion: The preventive effect of fish consumption is best achieved by increasing dietary fish in the first year of life.

Role of dietary lipids in food allergy

The prevalence of food allergy is raising in industrialized countries, but the mechanisms behind this increased incidence are not fully understood. Environmental factors are believed to play a role in allergic diseases, including lifestyle influences, such as diet. There is a close relationship between allergens and lipids, with many allergenic proteins having the ability to bind lipids. Dietary lipids exert pro-inflammatory or anti-inflammatory functions on cells of the innate immunity and influence antigen presentation to cells of the adaptive immunity. In addition to modifying the immunostimulating properties of proteins, lipids also alter their digestibility and intestinal absorption, changing allergen bioavailability. This study provides an overview of the role of dietary lipids in food allergy, taking into account epidemiological information, as well as results of mechanistic investigations using in vivo, ex vivo and in vitro models. The emerging link among high-fat diets, obesity, and allergy is also discussed.

Relationship between Serum Omega-3 Fatty Acid and Asthma Endpoints

Recent studies have highlighted the potential protective role of omega-3 polyunsaturated fatty acids (n-3 PUFA) in asthma. This study aimed at determining the association between seafood intake, serum PUFA composition and clinical endpoints of asthma in adults. A cross-sectional study of 642 subjects used the European Committee Respiratory Health Survey (ECRHS) questionnaire, skin prick tests, spirometry and methacholine challenge tests following ATS guidelines. Sera was analysed for n-3 and n-6 PUFA composition. Subjects had a mean age of 34 years, were largely female (65%) and 51% were current smokers. While 99% reported fish consumption, rock lobster, mussels, squid and abalone were also consumed less frequently. The prevalence of asthma symptoms was 11%, current asthma (ECRHS definition) was 8% and non-specific bronchial hyperresponsiveness (NSBH) was much higher (26%) In adjusted models the n-3 PUFAs 20:5 (EPA) and 22:5 (DPA) were significantly associated with a decreased risk of having NSBH. Total n-3 PUFA composition was associated with decreased NSBH risk (OR = 0.92), while high n-6 PUFA composition was associated with an increased risk (OR = 1.14).

Highlights and recent developments in airway diseases in EAACI journals (2017)

The European Academy of Allergy and Clinical Immunology (EAACI) owns three journals: Allergy, Pediatric Allergy and Immunology and Clinical and Translational Allergy. One of the major goals of EAACI is to support health promotion in which prevention of allergy and asthma plays a critical role and to disseminate the knowledge of allergy to all stakeholders including the EAACI junior members. There was substantial progress in 2017 in the identification of basic mechanisms of allergic and respiratory disease and the translation of these mechanisms into clinics. Better understanding of molecular and cellular mechanisms, efforts for the development of biomarkers for disease prediction, novel prevention and intervention studies, elucidation of mechanisms of multimorbidies, entrance of new drugs in the clinics as well as recently completed phase three clinical studies and publication of a large number of allergen immunotherapy studies and metaanalyses have been the highlights of the last year.

Dietary intake of fish and ω-3 polyunsaturated fatty acids and physician-diagnosed allergy in Japanese population: The Japan Environment and Children's Study

OBJECTIVE

Emerging evidence from epidemiologic studies and clinical trials indicates that ω-3 polyunsaturated fatty acids (PUFAs) may have a preventive or therapeutic effect on allergy, although the results remain controversial. The aim of this study was to investigate the association between intake of fish and ω-3 PUFAs with risk for lifetime prevalence of physician-diagnosed allergy in a Japanese population.

METHODS

Study participants were 78 621 pregnant women and 42 831 male partners from The Japan Environment and Children's Study. History of physician-diagnosed allergy (asthma, allergic rhinitis/pollinosis, allergic conjunctivitis, or atopic dermatitis) was determined by self-administered questionnaire survey. Dietary intake of fish and ω-3 PUFAs was estimated using a food frequency questionnaire.

RESULTS

Contrary to our hypothesis, an increased risk for allergy was found by multivariable logistic regression in females, especially in allergic rhinitis/pollinosis, allergic conjunctivitis, or atopic dermatitis for fish intake and in allergic rhinitis/pollinosis or allergic conjunctivitis for ω-3 PUFAs. As for male partners, risk for allergic rhinitis/pollinosis or atopic dermatitis was increased for both fish and ω-3 PUFA intake. No statistically significant results were observed for the risk for asthma in either women or men.

CONCLUSION

Fish and ω-3 PUFA intake were associated with increased risk for some allergic diseases. Further research is warranted to confirm these findings in individuals with high fish consumption.

Food consumption and the risk of childhood allergy

Background

The prevalence of allergic conditions is increasing in most countries. One possible explanation may be childhood nutrition.

Objective

The aim of the study was to investigate the relationship between consumption of pre-specified types of food in school-aged children and presence of respiratory and allergic symptoms.

Methods

A total of 191 students aged 9-11 years were recruited from 5 schools to geographically cover all of Malta. Data was collected between October 2011 and February 2012. This was part of a bigger study which included clinical and environmental tests besides standardized health questionnaires. For the purposes of this part of the study only the health questionnaires were used. These standardized health questionnaires based on the International Study of Asthma and Allergies in Childhood (ISAAC) were used to identify the presence of respiratory and allergic symptoms and to identify the types of foods and the frequency of consumption of various types of foods.

Results

We found that milk, meat, butter, olive oil, and yoghurt consumption had a negative association with allergic symptoms in children, whilst fish consumption had a detrimental effect. These relationships remained significant after correction for paternal level of education.

Conclusion

The study highlights the fact that nutrition in early childhood may have a significant effect on the risk of allergic conditions. Our results, taken together with data in the literature, suggest that different types of fish might have had different effects. This is probably related to their different fatty acid constitution thus warranting further studies.

The role of fish intake on asthma in children: A meta-analysis of observational studies

BACKGROUND

The evidence is mixed on the use of long chain Omega-3 fatty acids in the prevention and management of childhood asthma.

METHODS

We conducted a systematic search and meta-analysis investigating the role of fish intake, the main dietary source of long chain omega-3 fatty acids, on asthma in children.

RESULTS

A total of 1119 publications were identified. Twenty-three studies on fish intake in association with childhood asthma were included in the final review. In 15 of 23 studies, early introduction of fish (6-9 months) and regular consumption (at least once a week) improved asthma symptoms and reduced risk in children 0-14 years as compared to no fish consumption; 6 of 23 showed no effect and 2 of 23 studies suggest adverse effects. Meta-analysis revealed an overall "beneficial effect" for "all fish" intake on "current asthma" [OR: 0.75; 95%CI: 0.60-0.95] and "current wheeze" [OR: 0.62; 95%CI: 0.48-0.80] in children up to 4.5 years old. An overall protective effect of "fatty fish" intake as compared to "no fish" intake in children 8-14 years old was also observed [OR: 0.35; 95%CI: 0.18-0.67].

CONCLUSION

This meta-analysis suggests that introduction of fish early in life (6-9 months) and regular consumption of all fish (at least once a week) reduces asthma and wheeze in children up to 4.5 years old, while fatty fish intake may be beneficial in older children. Future well-designed clinical trials are recommended to confirm the promising findings documented in this literature analysis.

As You Eat It: Effects of Prenatal Nutrition on Asthma

Asthma most frequently develops early in life, and increased recognition of the role of lifestyle and environmental factors in asthma susceptibility raises the possibility that dietary exposures during pregnancy may influence the risk of asthma in offspring. This review discusses the latest evidence with regard to the effect of diet during pregnancy on childhood asthma risk, including potential mechanisms, outcomes of randomized clinical trials, and results from observational studies. Vitamin D and polyunsaturated fatty acid intake during pregnancy are highlighted as areas with large and growing bodies of literature to support a potential role in prenatal modulation of subsequent asthma risk. Several other nutritional interventions are under active investigation, and recommendations regarding dietary modifications during pregnancy will likely need to be personalized based on factors such as maternal smoking and genetic variants. Although nutrition during pregnancy is uniquely challenging to investigate, and definitive recommendations cannot be made without additional high-quality evidence and knowledge regarding long-term effects of interventions, the modifiable nature of the diet and sizeable potential reduction of morbidity supports ongoing research to determine how to optimize nutrition during pregnancy to prevent asthma in offspring.

Respiratory Health Symptoms among Schoolchildren in Relation to Possible Food-Related Risk and Protective Factors

Respiratory health outcomes are among the top five causes of child morbidity and mortality around the world. We aimed to investigate possible food-related risk and protective factors for respiratory health outcomes in children. Structured questionnaires completed by primary caregivers of 10-year old children were used to collect information on demographics, socio-economic status, house characteristics and child respiratory health status. Upper (URIs) and Lower (LRIs) respiratory illnesses comprised hay fever, and wheezing, asthma and bronchitis, respectively. Eight hundred questionnaires were distributed, 648 retrieved and 420 completed in full (52.5% response rate). The hay fever 6-month prevalence was 22.4% and wheezing had the highest 6-month prevalence among the LRIs (13.8%). The majority of children ate vegetables (75.5%), fruit (69.3%) and chicken or fish (81.7%) regularly. Nearly half of the children (45.5%) regularly ate processed food. Eating processed food regularly was statistical significantly associated with wheeze (Adjusted Odds Ratio (OR) = 2.65; 95% CI: 1.38–5.08), hay fever (OR = 1.62; 95% CI: 1.09–2.64) and bronchitis (OR = 1.27; 95% CI: 1.06–2.56). The study found an association between regular consumption of processed foods and wheeze, hay fever and bronchitis among 10 year old children. The regular consumption of processed food plays a role in adverse respiratory health effects among children and healthy eating is emphasized.

Diet during pregnancy and infancy and risk of allergic or autoimmune disease: A systematic review and meta-analysis

BACKGROUND

There is uncertainty about the influence of diet during pregnancy and infancy on a child's immune development. We assessed whether variations in maternal or infant diet can influence risk of allergic or autoimmune disease.

METHODS AND FINDINGS

Two authors selected studies, extracted data, and assessed risk of bias. Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess certainty of findings. We searched Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Web of Science, Central Register of Controlled Trials (CENTRAL), and Literatura Latino Americana em Ciências da Saúde (LILACS) between January 1946 and July 2013 for observational studies and until December 2017 for intervention studies that evaluated the relationship between diet during pregnancy, lactation, or the first year of life and future risk of allergic or autoimmune disease. We identified 260 original studies (964,143 participants) of milk feeding, including 1 intervention trial of breastfeeding promotion, and 173 original studies (542,672 participants) of other maternal or infant dietary exposures, including 80 trials of maternal (n = 26), infant (n = 32), or combined (n = 22) interventions. Risk of bias was high in 125 (48%) milk feeding studies and 44 (25%) studies of other dietary exposures. Evidence from 19 intervention trials suggests that oral supplementation with nonpathogenic micro-organisms (probiotics) during late pregnancy and lactation may reduce risk of eczema (Risk Ratio [RR] 0.78; 95% CI 0.68-0.90; I2 = 61%; Absolute Risk Reduction 44 cases per 1,000; 95% CI 20-64), and 6 trials suggest that fish oil supplementation during pregnancy and lactation may reduce risk of allergic sensitisation to egg (RR 0.69, 95% CI 0.53-0.90; I2 = 15%; Absolute Risk Reduction 31 cases per 1,000; 95% CI 10-47). GRADE certainty of these findings was moderate. We found weaker support for the hypotheses that breastfeeding promotion reduces risk of eczema during infancy (1 intervention trial), that longer exclusive breastfeeding is associated with reduced type 1 diabetes mellitus (28 observational studies), and that probiotics reduce risk of allergic sensitisation to cow's milk (9 intervention trials), where GRADE certainty of findings was low. We did not find that other dietary exposures-including prebiotic supplements, maternal allergenic food avoidance, and vitamin, mineral, fruit, and vegetable intake-influence risk of allergic or autoimmune disease. For many dietary exposures, data were inconclusive or inconsistent, such that we were unable to exclude the possibility of important beneficial or harmful effects. In this comprehensive systematic review, we were not able to include more recent observational studies or verify data via direct contact with authors, and we did not evaluate measures of food diversity during infancy.

CONCLUSIONS

Our findings support a relationship between maternal diet and risk of immune-mediated diseases in the child. Maternal probiotic and fish oil supplementation may reduce risk of eczema and allergic sensitisation to food, respectively.

Dietary intervention for preventing food allergy in children

PURPOSE OF REVIEW

In the past decade, food allergy has been increasingly recognized as an important public health issue. The role of maternal and infant diet in the development of food allergy has been a major focus of research throughout this period. Recently, research in this area has moved from observational studies to intervention trials, and the findings from these trials have started to influence infant feeding guidelines. In this article, we review recent studies of dietary interventions for preventing food allergy, summarize current knowledge and discuss future research directions.

RECENT FINDINGS

The latest result from an intervention trial shows that introduction of peanut in the first year of life reduces the risk of peanut allergy in high-risk infants. A systematic review and meta-analysis of intervention trials also suggests a protective effect of egg introduction from around 4 to 6 months of age for reducing the risk of egg allergy, with most studies conducted in high-risk infants. Despite several intervention trials involving modifications to the maternal diet, the effect of maternal diet during pregnancy and lactation in preventing food allergy remains unclear.

SUMMARY

Earlier introduction of allergenic foods is a promising intervention to reduce the risk of some food allergies in high-risk infants. Further work is needed to improve knowledge of how to prevent food allergy in the general population.