Infant feeding practices and reported food allergies at 6 years of age

Breastfeeding and risk of food allergy and allergic rhinitis in offspring: a systematic review and meta-analysis of cohort studies

The association between breastfeeding and the occurrence of allergic rhinitis (AR) and food allergy (FA) in offspring remains inconclusive. This review aims to comprehensively explore the potential relationships between various patterns and durations of breastfeeding and allergic diseases in offspring. We systematically searched PubMed, EMBASE, Cochrane, WOS databases, and Google Scholar for observational studies published up to March 30, 2023, that investigated the link between breastfeeding and allergies in offspring. The quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS) and Joanna Briggs Institute (JBI). Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated employing an appropriate model based on the degree of heterogeneity. A total of 68 studies, encompassing 772,142 children, were ultimately included. The findings indicated that breastfeeding for more than 6 months was associated with a reduced risk of AR (OR = 0.88, 95% CI: 0.79 to 0.98) but posed a risk for FA (OR = 1.69, 95% CI: 1.27 to 2.25). Exclusive breastfeeding exhibited a protective effect against AR (OR = 0.94, 95% CI: 0.90 to 0.97), whereas non-breastfeeding was identified as a risk factor for AR (OR = 1.48; 95% CI: 1.03 to 2.12). No significant association was observed between breastfeeding patterns and FA.

CONCLUSION

Breastfeeding for more than 6 months proves to be an effective preventive measure against AR. However, large prospective high-quality studies are needed to investigate the potential risk of FA in children with prolonged breastfeeding.

WHAT IS KNOWN

• The impact of breastfeeding on allergic rhinitis and food allergy in offspring is controversial. • Previous meta-analyses fail to prove the effect of breastfeeding on food allergy in offspring of all ages.

WHAT IS NEW

• Breastfeeding for more than 6 months proves to be an effective preventive measure against AR. However, it potentially elevates the risk of FA in children. Non-breastfeeding is linked to an increased risk of AR in children, but there is no evidence of an association between breastfeeding patterns and FA in children. • The impact of breastfeeding on allergic rhinitis and food allergy in offspring may vary with the time and pattern of breastfeeding.

Effects of Early Diet on the Prevalence of Allergic Disease in Children: A Systematic Review and Meta-Analysis

Recent evidence suggests that the timing of introduction, types, and amounts of complementary foods/allergenic foods may influence the risk of allergic disease. However, the evidence has not been updated and comprehensively synthesized. The Cochrane Library, EMBASE, Web of Science, and PubMed databases were searched from the inception of each database up to 31 May 2023 (articles prior to 2000 were excluded manually). Statistical analyses were performed using RevMan 5. The GRADE approach was followed to rate the certainty of evidence. Compared with >6 mo, early introduction of eggs (≤6 mo of age) might reduce the risk of food allergies in preschoolers aged <6 y (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.53, 0.81), but had no effect on asthma or atopic dermatitis (AD). Consumption of fish at 6-12 mo might reduce the risk of asthma in children (aged 5-17 y) compared with late introduction after 12 mo (OR, 0.61; 95% CI: 0.52, 0.72). Introduction of allergenic foods for ≤6 mo of age, compared with >6 mos, was a protective factor for the future risk (children aged ≤10 y) of AD (OR, 0.93; 95% CI: 0.89, 0.97). Probiotic intervention for infants at high risk of allergic disease significantly reduced the risk of food allergy at ages 0-3 y (OR, 0.72; 95% CI: 0.56, 0.94), asthma at 6-12 y (OR, 0.61; 95% CI: 0.41, 0.90), and AD at aged <6 y (3-6 y: OR, 0.70; 95% CI: 0.52, 0.94; 0-3 y: OR, 0.73; 95% CI: 0.59, 0.91). Early introduction of complementary foods or the high-dose vitamin D supplementation in infancy was not associated with the risk of developing food allergies, asthma, or AD during childhood. Early introduction to potential allergen foods for normal infants or probiotics for infants at high risk of allergies may protect against development of allergic disease. This study was registered at PROSPERO as CRD42022379264.

Optimal timing of introduction of complementary feeding: a systematic review and meta-analysis

CONTEXT

The timing of introducing complementary feeding (CF) is crucial because premature or delayed CF can be associated with adverse health outcomes in childhood and adulthood.

OBJECTIVE

This systematic review aims to evaluate the impact of the timing of CF introduction on health, nutrition, and developmental outcomes among normal-term infants.

DATA SOURCES

Electronic databases and trial registries were searched, along with the reference lists of the included studies and relevant systematic reviews.

DATA EXTRACTION

Two investigators independently extracted data from the included studies on a standardized data-extraction form.

DATA ANALYSIS

Data were meta-analyzed separately for randomized controlled trials (RCTs) and observational studies on the basis of early introduction of CF (< 3 months, < 4 months, < 6 months of age) or late introduction of CF (> 6 months, > 8 months of age). Evidence was summarized according to GRADE criteria. In total, 268 documents were included in the review, of which 7 were RCTs (from 24 articles) and 217 were observational studies (from 244 articles). Evidence from RCTs did not suggest an impact of early introduction, while low-certainty evidence from observational studies suggested that early introduction of CF (< 6 months) might increase body mass index (BMI) z score and overweight/obesity. Early introduction at < 3 months might increase BMI and odds of lower respiratory tract infection (LRTI), and early introduction at < 4 months might increase height, LRTI, and systolic and diastolic blood pressure (BP). For late introduction of CF, there was a lack of evidence from RCTs, but low-certainty evidence from observational studies suggests that late introduction of CF (> 6 months) might decrease height, BMI, and systolic and diastolic BP and might increase odds of intestinal helminth infection, while late introduction of CF (> 8 months) might increase height-for-age z score.

CONCLUSION

Insufficient evidence does suggest increased adiposity with early introduction of CF. Hence, the current recommendation of introduction of CF should stand, though more robust studies, especially from low- and middle-income settings, are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020218517.

Food allergy and infant feeding practices: Are they related?

BACKGROUND

Immunoglobulin (Ig)E-mediated food allergy is a growing health problem affecting up to 10% of children. It is well-established that early introduction to peanuts and eggs from 4 months of age has a preventive effect. In contrast, there is no consensus about the effect of breastfeeding on food allergy development.

OBJECTIVE

To evaluate the effect of breastfeeding and cows' milk formula (CMF) feeding on the development of IgE-mediated food allergy.

METHODS

Infants in the Cow's Milk Early Exposure Trial were followed for 12 months. The cohort was divided according to parental feeding preferences for the first 2 months of life: group 1: exclusive breastfeeding (EBF); group 2: breastfeeding with at least 1 daily meal of CMF; and group 3: feeding with CMF only.

RESULTS

Among a total of 1989 infants, 1071 were on EBF (53.8%), 616 were breastfed with addition of CMF (31%), and 302 were fed with CMF only (15.2%), from birth. By 12 months, 43 infants developed an IgE-mediated food allergy (2.2%); 31 in the EBF group (2.9%), 12 in the breastfeeding and CMF combined group (1.9%), and none in the CMF feeding-only group (P = .002). Family atopic comorbidity did not affect the results.

CONCLUSION

In this prospective cohort, breastfed infants developed significantly higher rates of IgE-mediated food allergy during the first year of life. Perhaps the mechanism is related to compounds ingested by the mother and secreted in the breastmilk. Future larger cohorts should validate these results and offer the lactating mother recommendations.

TRIAL REGISTRATION

The COMEET study and its derivatives were approved by the Ethics Committee of Meir Medical Center, IRB number 011-16-MMC. It was registered at the National Institutes of Health Clinical Trials Registry: NCT02785679.

Complementary feeding practices are related to the risk of food allergy in the ELFE cohort

BACKGROUND

Conflicting results have been obtained when analyzing the relationship between complementary feeding (CF) practices and allergic diseases in childhood. This study aims to further explore the association between allergic diseases in early childhood (10.1016/j.jaci.2012.02.036) and the age at CF introduction (10.1016/S0140-6736(15)00149-X), food diversity in the first year of life (10.1016/j.ijporl.2019.109759) and the delayed introduction of major allergenic foods.

METHODS

This analysis focused on 6662 children from the French nationwide ELFE cohort. Data on feeding practices were collected monthly from 3 to 10 months old. Their age at CF introduction was calculated alongside a diversity score, and the number of major allergenic foods (out of eggs, fish, wheat, and dairy products) not introduced at 8 and 10 months. Their associations with parent-reported allergy-related health events between 1 and 5.5 years were assessed using logistic regressions adjusted for confounding factors. A sensitivity analysis excluding early allergic cases (occurring between 2 months and 1 or 2 years) was conducted.

RESULTS

Late CF (>6 months) was related to a higher risk of food allergy (OR [95% CI] = 1.35 [1.02; 1.78]), a low diversity score at 8 months to a higher risk of asthma (OR [95% CI] = 1.22 [1.01; 1.48]), and two allergenic foods or more not being introduced at 10 months to a higher risk of rhinoconjunctivitis (OR [95% CI] = 1.20 [1.00; 1.44]) and food allergy (OR [95% CI] = 2.46 [1.77; 3.42]). Only this last association remained significant after the exclusion of early cases.

CONCLUSION

The delayed introduction of major allergenic foods is related to a higher risk of food allergy, which supports the updated guidelines for allergy prevention.

Frequency of Infant Egg Consumption and Risk of Maternal-Reported Egg Allergy at 6 Years

BACKGROUND

Recent research suggests that early egg introduction during infancy may help to prevent egg allergy development. However, the infant egg consumption frequency that is sufficient to induce this immune tolerance remains uncertain.

OBJECTIVES

We examined the associations between the infant egg consumption frequency and maternal-reported child egg allergy at 6 y.

METHODS

We analyzed data of 1252 children from the Infant Feeding Practices Study II (2005-2012). Mothers reported the frequency of infant egg consumption at 2, 3, 4, 5, 6, 7, 9, 10, and 12 mo old. Mothers reported the status of their child's egg allergy at the 6-y follow-up. We used Fisher exact test, Cochran-Armitage Trend Test, and log Poisson regression models to compare 6-y egg allergy risk by the frequency of infant egg consumption.

RESULTS

The risk of maternal-reported egg allergy at 6 y significantly (P-trend = 0.004) decreased with infant egg consumption frequency at 12 mo: 2.05% (11/537) for infants not consuming eggs, 0.41% (1/244) for those consuming eggs <2 times per wk, and 0.21% (1/471) for those consuming eggs ≥2 times per wk. A similar but nonsignificant trend (P-trend=0.109) was observed for egg consumption at 10 mo (1.25%, 0.85%, and 0%, respectively). After adjusting for socioeconomic confounders, breastfeeding, complementary food introduction, and infant eczema, infants who consumed eggs ≥2 times per wk at 12 mo had a significantly lower RR of maternal-reported egg allergy at 6 y (confounder-adjusted RR: 0.11; 95% CI: 0.01, 0.88; P = 0.038), whereas those who consumed <2 times per wk (confounder-adjusted RR: 0.21; 95% CI: 0.03, 1.67; P = 0.141) did not have a significantly lower risk than those who did not consume eggs at all.

CONCLUSIONS

Consumption of eggs ≥2 times per wk in late infancy is associated with a reduced risk of developing egg allergy later in childhood.

Timing of Cow's Milk or Cow's Milk Formula Introduction to the Infant Diet and Atopic Risk in Children: a Systematic Review and Meta-analysis

Infant feeding is an important early-life exposure that may influence the development of atopic disease. The optimal timing of introduction of food allergens, including cow's milk (CM), is not known. This study aims to systematically review the evidence describing the effects of timing of CM or cow's milk formula (CMF) introduction to the infant diet on the development of atopic diseases during childhood. Pubmed, Embase, CINAHL, Cochrane CENTRAL, and CNKI were searched through May 30, 2019. Study screening and data extraction by two reviewers followed the PRISMA statement. Data were extracted independently in duplicate, and meta-analyses were performed by pooling unadjusted and adjusted odds ratio (OR) separately. Heterogeneity was explored using I² and publication bias by funnel plots and Begg's tests. In total, 45 studies from 20 countries were included. Meta-analyses using adjusted data showed that no associations were observed between early introduction of CM or CMF and the risk of asthma (< 4 vs. ≥ 4 months: OR 1.16, 95% confidence interval (CI) 0.89, 1.51), wheeze (< 6 vs. ≥ 6 months: OR 1.15, 95% CI 0.85, 1.56), and eczema or atopic dermatitis (< 6 vs. ≥ 6 months: OR 0.96, 95% CI 0.65, 1.41). Overall, quite little high-quality evidence was identified to allow for definitive conclusions on the association between early CM or CMF introduction and risk of allergic diseases. Our meta-analysis on this topic highlights the specific gaps in information for public recommendations regarding CM or CMF feeding practice in an early stage of life, particularly before 3 months of age.

A Consensus Approach to the Primary Prevention of Food Allergy Through Nutrition: Guidance from the American Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; and the Canadian Society for Allergy and Clinical Immunology

Recently published data from high-impact randomized controlled trials indicate the strong potential of strategies to prevent the development of food allergy in high-risk individuals, but guidance in the United States at present is limited to a policy for only the prevention of peanut allergy, despite other data being available and several other countries advocating early egg and peanut introduction. Eczema is considered the highest risk factor for developing IgE-mediated food allergy, but children without risk factors still develop food allergy. To prevent peanut and/or egg allergy, both peanut and egg should be introduced around 6 months of life, but not before 4 months. Screening before introduction is not required, but may be preferred by some families. Other allergens should be introduced around this time as well. Upon introducing complementary foods, infants should be fed a diverse diet, because this may help foster prevention of food allergy. There is no protective benefit from the use of hydrolyzed formula in the first year of life against food allergy or food sensitization. Maternal exclusion of common allergens during pregnancy and/or lactation as a means to prevent food allergy is not recommended. Although exclusive breast-feeding is universally recommended for all mothers, there is no specific association between exclusive breast-feeding and the primary prevention of any specific food allergy.

Do Human Milk Oligosaccharides Protect Against Infant Atopic Disorders and Food Allergy?

Atopic disorders (AD), often coexistent with food allergy (FA), start developing in early life and have lifelong health consequences. Breastfeeding is thought to be protective against AD and FA, but the data are controversial, and mechanisms are not well understood. Human milk oligosaccharides (HMOs) are complex carbohydrates that are abundant in human milk. These are thought to contribute to the development of the infant immune system by (i) promoting healthy microbiome, (ii) inhibiting pathogen binding to gut mucosa and (iii) modulating the immune system. Differences in microbiome composition between allergic and healthy infants have been observed, regardless of breastfeeding history. To date, limited studies have examined the preventive effects of HMOs on AD and FA in infants and current data relies on observation studies as trials of varying HMO intake through randomising individuals to breastfeeding are unethical. There is evidence for beneficial effects of breastfeeding on lowering the risks of FA, eczema and asthma but there are inconsistencies amongst studies in the duration of breastfeeding, diagnostic criteria for AD and the age at which the outcome was assessed. Furthermore, current analytical methods primarily used today only allow detection of 16-20 major HMOs while more than 100 types have been identified. More large-scale longitudinal studies are required to investigate the role of HMO composition and the impact of changes over the lactation period in preventing AD and FA later in life.

Breastfeeding and risk of food allergy: A nationwide birth cohort in Japan

BACKGROUND

Although breastfeeding has been well-established as the preferred method for infant nutrition, its prophylactic effects on food allergy remain controversial. Infantile eczema has been linked to food allergy via percutaneous sensitization; however, this relationship has not been considered in previous studies. We aimed to uncover the prophylactic effects of breastfeeding on food allergy, focusing on eczema-mediated percutaneous sensitization.

METHODS

This retrospective cohort study was based on 46,616 children from the Longitudinal Survey of Newborns in the 21st Century in Japan, begun in 2001. We classified participants into three groups based on infant feeding practices (exclusive breastfeeding, partial breastfeeding including only colostrum, and formula feeding only) and used information from at least one outpatient visit for food allergy during two observation periods (age 6-18 months and age 6-66 months) as health outcomes. We performed log-binomial regression analysis adjusted for potential confounders and stratified analysis according to infantile eczema status.

RESULTS

Compared with formula feeding, partial breastfeeding including only colostrum reduced the risk of food allergy only in children with infantile eczema, (RR = 0.66, 95% CI: 0.46, 0.96 for age 6-66 months), whereas exclusive breastfeeding increased this risk in those without infantile eczema (RR = 2.41, 95% CI: 1.40, 4.15, age 6-66 months). The prophylactic effects of breastfeeding on food allergy in the infantile eczema group increased with shorter breastfeeding duration.

CONCLUSIONS

Our results showed that breastfeeding, especially colostrum, had prophylactic effects on food allergy only among high-risk children with infantile eczema whereas prolonged breastfeeding increased the risk of food allergy.

Appropriate age range for introduction of complementary feeding into an infant's diet

Following a request from the European Commission, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) revised its 2009 Opinion on the appropriate age for introduction of complementary feeding of infants. This age has been evaluated considering the effects on health outcomes, nutritional aspects and infant development, and depends on the individual's characteristics and development. As long as foods have an age-appropriate texture, are nutritionally appropriate and prepared following good hygiene practices, there is no convincing evidence that at any age investigated in the included studies (< 1 to < 6 months), the introduction of complementary foods (CFs) is associated with adverse health effects or benefits (except for infants at risk of iron depletion). For nutritional reasons, the majority of infants need CFs from around 6 months of age. Infants at risk of iron depletion (exclusively breastfed infants born to mothers with low iron status, or with early umbilical cord clamping (< 1 min after birth), or born preterm, or born small-for-gestational age or with high growth velocity) may benefit from earlier introduction of CFs that are a source of iron. The earliest developmental skills relevant for consuming pureed CFs can be observed between 3 and 4 months of age. Skills for consuming finger foods can be observed in some infants at 4 months, but more commonly at 5-7 months. The fact that an infant may be ready from a neurodevelopmental perspective to progress to a more diversified diet before 6 months of age does not imply that there is a need to introduce CFs. There is no reason to postpone the introduction of potentially allergenic foods (egg, cereals, fish and peanut) to a later age than that of other CFs as far as the risk of developing atopic diseases is concerned. Regarding the risk of coeliac disease, gluten can be introduced with other CFs.

The Effect of Paid Family Leave on Infant and Parental Health in the United States

California's paid family leave (PFL) policy improved mothers' labor market outcomes, however, the health impacts of this program are less studied. I compare child and parental health of likely eligible households to a series of control groups before and after California's PFL program was implemented. I find improvements in parent-reported overall child health and suggestive improvements in maternal mental health status. Findings also suggest a reduction in asthma and a greater likelihood that parents feel they are coping well with the day-to-day demands of parenting. There are no significant effects on respiratory or food allergies, or father's mental health status. The results are robust to multiple control groups and placebo tests.

Prevention of allergy with diverse and healthy microbiota: an update

PURPOSE OF REVIEW

Microbiota consist of symbiotic microscopic neighbors that interact on and within our bodies in diverse and incompletely understood ways throughout our lifetime. Though various associations with allergic disease have been described, clear effective therapeutic interventions to prevent allergy have been elusive.

RECENT FINDINGS

The human microbiome is influenced by multiple factors, including: mode of infant delivery (vaginal vs. cesarean section), breastfeeding, diet, presence of siblings and pets, exposure to antibiotics and other medications (particularly antacids), lifestyle, and developmental context. Microbial species promoting atopic responses and tolerance have been described. Specific microbiota likely act through distinct metabolic pathways to promote the health of their human hosts, optimally directing the developing immune system away from pro-allergic, Th2-dominated responses to more T-regulatory-influenced behaviors.

SUMMARY

Evidence suggests that specific healthy infant microbiome signatures may influence development of some components of the allergic march of childhood by decreasing atopic dermatitis, asthma, and food allergy. Further understanding of factors that influence healthy microbiota may lead to specific strategies tailored for early intervention and disease prevention.

Age at introduction to complementary solid food and food allergy and sensitization: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

An infant's age at introduction of complementary solids may contribute to food allergy. We aimed to synthesize the literature on the association between age at introduction of complementary solids, excluding milk products, and food allergy and sensitization.

DESIGN

We searched the electronic databases PubMed and EMBASE (January 1946-February 2017) using solid food, allergy and sensitization terms.

METHODS

Two authors selected papers according to inclusion criteria, identifying 16 cohort studies, 1 case-control study and 8 randomized controlled trials (RCTs). Pooled effects across studies were estimated using random-effects meta-analysis.

RESULTS

Cohort studies-Introducing complementary solids at age ≥ 4 months vs <4 months was not associated with food allergy (OR 1.22; 95% CI, 0.76-1.96) but was associated with food sensitization (OR 1.93; 95% CI 1.57-2.38). First exposure from age 4 to 6 months vs <4 months was not associated with food allergy (OR 1.01; 95% CI, 0.64-1.60) but was associated with food sensitization (OR 2.46; 95% CI 1.55-3.86). Randomized controlled trials-Egg exposure from age 4 months was associated with reduced egg allergy (OR 0.63, 95% CI, 0.44-0.90) and sensitization (OR 0.76, 95% CI, 0.51-0.95). Peanut exposure from age 4 months compared to delayed exposure was associated with reduced peanut allergy (OR 0.28, 95% CI 0.14-0.57).

CONCLUSIONS

We found no evidence from observational studies that introducing solids before 4 months protected against food allergy, but there was evidence for protection against food sensitization. From RCTs, introducing egg from 4 to 6 months and peanut from 4 to 11 months reduced the risk of egg allergy, peanut allergy and egg sensitization. PROSPERO systematic review registry (CRD42016033473).

Complementary feeding and food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis: a systematic review

BACKGROUND

Nutrition during infancy and toddlerhood may influence health and disease prevention across the life span. Complementary feeding (CF) starts when human milk or infant formula is complemented by other foods and beverages, beginning during infancy and continuing to age 24 mo.

OBJECTIVES

The aim of this study was to describe systematic reviews conducted for the USDA and the Department of Health and Human Services Pregnancy and Birth to 24 Months Project to answer the following question: What is the relationship between the timing of the introduction of complementary foods and beverages (CFBs), or types and amounts of CFBs consumed, and the development of food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis?

METHODS

The literature was searched using 4 databases (CINAHL, Cochrane, Embase, PubMed) to identify articles published from January 1980 to February 2017 that met predetermined inclusion criteria. For each study, data were extracted and risk of bias was assessed. The evidence was qualitatively synthesized to develop a conclusion statement, and the strength of the evidence was graded.

RESULTS

Thirty-one included articles addressed the timing of CFB introduction, and 47 articles addressed the types and amounts of CFBs consumed.

CONCLUSIONS

Moderate evidence suggests that there is no relationship between the age at which CF first begins and the risk of developing food allergy, atopic dermatitis/eczema, or childhood asthma. Limited to strong evidence, depending on the specific food, suggests that introducing allergenic foods in the first year of life (after 4 mo) does not increase the risk of food allergy and atopic dermatitis/eczema but may prevent peanut and egg allergy. There is not enough evidence to determine a relationship between diet diversity or dietary patterns and atopic disease. Research is needed to address gaps and limitations in the evidence on CF and atopic disease, including research that uses valid and reliable diagnostic measures and accounts for key confounders and potential reverse causality.

Wheeze and Food Allergies in Children Born via Cesarean Delivery: The Upstate KIDS Study

We examined whether cesarean delivery (CD) increased the risk of wheeze or food allergy in early childhood compared with vaginal delivery and whether these associations were mediated by breastfeeding. The study population was the Upstate KIDS cohort (2008-2010) of mothers and infants from the State of New York (excluding New York City). Infant's wheeze was reported by questionnaire every 4-6 months until 3 years of age, as were food allergies beginning at 8 months. Modified Poisson regression was used to compare risks of the outcomes according to mode of delivery (MOD). Potential confounders were identified a priori using directed acyclic graphs. Emergency CD (n = 1,356) was associated with elevated risk of wheeze, adjusting for pregnancy complications, maternal atopy, gestational age, birth weight, and smoking during pregnancy (risk ratio = 2.47, 95% confidence interval: 1.31, 4.66), and an increased risk of food allergy, adjusting for maternal atopy, prepregnancy body mass index, smoking during pregnancy, and parity (risk ratio = 3.02, 95% confidence interval: 1.26, 7.25). Neither outcome was significantly associated with planned CD (n = 1,565 infants). Breastfeeding mediated the association between MOD and wheeze but not food allergy. Other factors not associated with early-life microbial transfer, but relating to the development of the outcomes, might contribute to the association between MOD and wheeze/food allergy.

Human Breast Milk NMR Metabolomic Profile across Specific Geographical Locations and Its Association with the Milk Microbiota

The composition of human breast milk is highly variable, and it can be influenced by genetics, diet, lifestyle, and other environmental factors. This study aimed to investigate the impact of geographical location and mode of delivery on the nuclear magnetic resonance spectroscopy (NMR) metabolic profile of breast milk and its relationship with the milk microbiome. Human milk metabolic and microbiota profiles were determined using NMR and 16S rRNA gene sequencing, respectively, in 79 healthy women from Finland, Spain, South Africa, and China. Up to 68 metabolites, including amino acids, oligosaccharides, and fatty acid-associated metabolites, were identified in the milk NMR spectra. The metabolite profiles showed significant differences between geographical locations, with significant differences (p < 0.05) in the levels of galactose, lacto-N-fucopentaose III, lacto-N-fucopentaose I and 2-fucosyllactose, 3-fucosyllactose, lacto-N-difucohexaose II, lacto-N-fucopentaose III, 2-hydroxybutyrate, 3-hydroxybutyrate, proline, N-acetyl lysine, methyl-histidine, dimethylamine, kynurenine, urea, creatine and creatine phosphate, formate, lactate, acetate, phosphocholine, acetylcholine, LDL, VLDL, ethanolamine, riboflavin, hippurate, spermidine, spermine and uridine. Additionally, the effect of caesarean section on milk metabolome was dependent on the geographical region. Specific interrelations between human milk metabolites and microbiota were also identified. Proteobacteria, Actinobacteria, and Bacilli were most significantly associated with the milk metabolites, being either positively or negatively correlated depending on the metabolite. Our results reveal specific milk metabolomic profiles across geographical locations and also highlight the potential interactions between human milk’s metabolites and microbes.

Retrospective observational cohort study regarding the effect of breastfeeding on challenge-proven food allergy

BACKGROUND/OBJECTIVES

Human breast milk is generally regarded as the best nutrition for infants in their first months of life. Whether breastfeeding has a protective effect on food allergy is a point of debate and the subject of this study.

SUBJECTS/METHODS

This retrospective study was conducted in 649 children who underwent a double-blind placebo-controlled food challenge (DBPCFC) as part of routine care in a tertiary care clinic. Food allergy was defined as having at least one positive DBPCFC to any food. The association between both "any" breastfeeding (yes/no) and its duration in months with food allergy was studied by logistic regression analysis with correction for confounding variables.

RESULTS

The prevalence of food allergy was 58.9% (n = 382). Of all subjects, 75.8% (n = 492) was breastfed and 24.2% (n = 157) bottle-fed. There was no significant association between food allergy and breastfeeding versus bottle-feeding after correction for the confounding effect of increased breastfeeding by atopic parents and a history of asthma in the child (OR = 1.24, 95% CI = 0.85-1.79, p = 0.27). However, in breastfed children, every additional month of breastfeeding lowered the risk for food allergy by ~4% (OR = 0.96, 95% CI = 0.93-0.99, p = 0.02). No confounders were identified in this association.

CONCLUSION

These results show for the first time that in children investigated for possible food allergy, every additional month of breastfeeding is associated with a lower risk of developing clinical food allergy as diagnosed by DBPCFC. However, overall, there was no association between the prevalence of food allergy and breastfeeding versus bottle-feeding in this tertiary care population.

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.

Infant feeding patterns and eczema in children in the first 6 years of life

BACKGROUND

Modes of infant feeding such as direct and indirect breastfeeding, and formula feeding, and their combinations may play a role in child health.

OBJECTIVE

The aim was to investigate which feeding patterns in the first 6 months pose risks of eczema/skin allergy in children up to 6 years compared to direct breastfeeding for at least 3 months.

METHODS

The Infant Feeding Practices Study II in the United States and its 6-year follow-up provided data on feeding modes in infancy and doctor's diagnosed eczema/skin allergy in the first 6 years of life (1387 infants), based on parental reports. Different feeding patterns were identified. Log-linear models were used to estimate prevalence ratios (PRs) of feeding patterns for doctor's diagnosed eczema/skin allergy in the first 6 years of life, adjusting for confounders.

RESULTS

Compared to "direct breastfeeding for at least 3 months" (DBF3m), the combination of "direct feeding at the breast (DBF), pumping and feeding breast milk (BM), and formula (FF) in the first months" (DBF/BM/FF) showed a statistically significant higher risk of eczema/skin allergy in the first 6 years of life (PR = 1.46), adjusting for confounders. DBF combined with BM for the first 3 months followed by mixed feeding also had an increased risk (PR = 1.26), although not statistically significant. Formula feeding introduced since birth had no effect on eczema. Among the confounders, paternal eczema and race/ethnicity (Hispanic vs White) were associated with a higher risk of eczema/skin allergy.

CONCLUSIONS & CLINICAL RELEVANCE

Mixed infant feeding may carry a higher risk of eczema/skin allergy compared to direct feeding at the breast. The recent epidemic of pumping and feeding in the United States and the use of mixed infant feeding modes requires additional studies to provide appropriate and renewed assessments of the risks of feeding modes for the future development of allergies.

Introducing Allergenic Food into Infants' Diets: Systematic Review

PURPOSE

The purpose of this systematic review was to explore the association between timing of introduction of potentially allergenic foods to infants and development of food allergies.

METHODS

CINAHL, Medline, PubMed, Science Direct, and Web of Science were searched using the terms solid food, complementary food, or infant feeding combined with allergy or hypersensitivity for articles published in English in 2000 or later. Inclusion criteria were 1) primary research articles with 2) a focus on association between introduction of complementary foods including potentially allergenic foods into diets of infants less than 12 months of age and development of food allergies. Articles were excluded if they were 1) not primary research, 2) about complementary foods only (without specificity of allergenic foods), or 3) on allergic conditions other than food allergy (such as asthma or eczema).

RESULTS

The initial literature search yielded 533 articles; 14 articles met inclusion criteria. Level of evidence of each study was determined with the SORT criteria. Results found that delayed introduction of solid foods in general and allergenic foods in particular was not associated with decreased risk for allergic diseases among high and low-risk infants. Later introduction was associated with increased risk for allergy development.

CLINICAL IMPLICATIONS

For infants at low risk for development of food allergies, providers should advise caregivers to introduce potentially allergenic foods with other solid foods between 4 and 6 months of age when children show an interest in eating solids. Infants at high risk for peanut allergy, should be evaluated by an allergy specialist prior to introduction of peanuts and work with providers to create an individualized plan for introduction of peanuts and other allergenic foods as needed.

LEAPing through the looking glass: secondary analysis of the effect of skin test size and age of introduction on peanut tolerance after early peanut introduction

BACKGROUND

In the Learning Early About Peanut Allergy (LEAP) study, early peanut introduction in high-risk 4- to 11-month-olds was associated with a significantly decreased risk of developing peanut allergy. However, the influences of key baseline high-risk factors on peanut tolerance are poorly understood.

METHODS

Secondary analysis was conducted on the publically available LEAP dataset, exploring relationships between peanut tolerance, baseline peanut/egg sensitization, eczema severity/duration, age of introduction, gender, and race.

RESULTS

A multiple logistic regression model predicting odds of successful oral food challenge (OFC) at 60 months noted higher odds with early introduction (OR 9.2, P < 0.001, 95% CI 4.2-20.3), white race (OR 2.1, P = 0.04, 95% CI 1.1-3.9), and advancing age (OR 4.8, P = 0.04, 95% CI 1.1-20.8). Odds of peanut tolerance were lower with increasing peanut wheal size (OR 0.58, P < 0.001, 95% CI 0.46-0.74), increased baseline SCORAD score (OR 0.98, P = 0.04, 95% CI 0.97-1), and increased kU_A /l of egg serum IgE (sIgE) (OR 0.99, P = 0.04, 95% CI 0.98-1). The probability of peanut tolerance in the early introduction group was 83% vs 43% in the avoidance group with SPT wheal of <4 mm. The probability of a successful OFC was significantly higher with peanut introduction between 6 and 11 months than at 4-6 months. Increasing eczema severity had limited impact on the probability of peanut tolerance in the early introduction arm.

CONCLUSION

Increasing peanut wheal size predicted peanut tolerance only in the avoidance arm. Peanut introduction between 6 and 11 months of age was associated with the highest rates of peanut tolerance, questioning the 'urgency' of introduction before 6 months.

A Limited Survey of Dark Chocolate Bars Obtained in the United States for Undeclared Milk and Peanut Allergens

Undeclared allergens in chocolate products have been responsible for numerous allergen-related recalls in the United States. A survey was conducted to determine the prevalence of undeclared milk and peanut in 88 and 78 dark chocolate bars, respectively. Concentrations of milk (as nonfat dry milk) or peanut in three samples of each chocolate product were determined with two milk- or peanut-specific enzyme-linked immunosorbent assay kits. In 75% of the chocolate bar products with a milk advisory statement, milk concentrations were above the limit of quantitation (2.5 μg/g [ppm]), with the majority having concentrations >1,000 ppm. An additional 67% of chocolate bars with a "traces of milk" statement contained 3 to 6,700 ppm of milk. Fifteen percent of chocolates labeled dairy free or lactose free and 25% labeled vegan were positive for milk, all with concentrations >1,000 ppm. Even for chocolates with no reference to milk on the label, 33% of these products contained 60 to 3,400 ppm of milk. The survey of chocolate products for peanuts revealed that 8% of products with an advisory statement contained peanut, with the highest concentration of 550 ppm. All nine chocolates bearing the peanut-free or allergen-free statement were negative for peanut, but 17% of chocolates with no label statement for peanut were positive for peanut at concentrations of 9 to 170 ppm. Evaluation of multiple lots of four chocolate products revealed that milk was consistently present or absent for the products investigated, but mixed results were obtained when multiple lots were tested for peanut. This study indicates that a large proportion of dark chocolate bars contain undeclared milk. The type of advisory statement or the absence of a milk advisory statement on products did not predict the amount or absence of milk protein. In contrast, a lower proportion of chocolates containing undeclared peanut was found. Consumers with food allergies should be cautious when purchasing dark chocolate products, particularly those that have an advisory label statement.

Modifying the infant's diet to prevent food allergy

Recommendations and guidelines on the prevention of food allergy have changed in recent decades. The aim of this review of the current evidence and ongoing studies is to provide a comprehensive and up to date picture of prevention of food allergy for healthcare professionals. The review was undertaken as part of the European Union funded Integrated Approaches to Food Allergy and Allergen Management (iFAAM) study. This is a wide ranging project bringing together expertise across the breadth of food allergy research. Specifically, the review discusses dietary manipulation in food allergy prevention, and covers the possible preventive strategies of allergen avoidance, early allergen introduction, general nutrition and supplements, as well as other strategies, such as prebiotics and probiotics. The review concludes that despite agreement that allergen avoidance strategies should not be undertaken for allergy prevention, there is currently no consensus regarding what actions should be recommended beyond exclusive breastfeeding for the first 4-6 months of life. Recent and upcoming trial results, which are detailed in this review, should help inform the debate and add clarity to the topic.

Food-Related Symptoms and Food Allergy in Swedish Children from Early Life to Adolescence

Background

Risk factors for persistence of food-related symptoms (FRS) and food allergy (FA) from early life to adolescence are incompletely understood. The aim of this study was to identify risk factors for FRS and FA in adolescence amongst children with FRS or FA in the first four years of life (early life).

Methods

In children enrolled in a Swedish birth cohort and followed to 16 years (n = 2572), we defined children with early life FRS in the absence of FA, and FA. Corresponding phenotypes were defined at 16 years. Associations between potential risk factors at 4 years and FRS and FA at 16 years were investigated using logistic regression.

Results

Early life FRS and FA prevalences were 12.2% and 6.8%, respectively. Amongst children with early life FRS, 35.7% had FRS or FA at 16 years, whereas 74.3% of the children with early life FA had FA at 16 years. For each of the early life phenotypes, parental allergy, early life allergic multimorbidity, early life reactions to peanuts/tree nuts and IgE reactivity at 4 years were statistically significantly associated with FRS or FA at 16 years. In contrast, male sex was associated with an increased risk of FA at 16 years among children with early life FA only.

Conclusions

In early life, food-related symptoms are twice as common as food allergy. Unlike food allergy, food-related symptoms often remit by adolescence. Yet, these phenotypes have many common risk factors for persistence to adolescence.

Household environment, lifestyle behaviors, and dietary habits in relation to childhood atopic eczema in Shanghai, China

PURPOSES

We aim to investigate associations of the child's individual characteristics, building characteristics, home environmental exposures, family lifestyle behaviors, and dietary habits on childhood eczema during lifetime-ever and in the last year before the survey.

METHODS

During April 2011-April 2012, we conducted a cross-sectional study and collected 13,335 parents-reported questionnaires of 4-6-year-old children from 72 kindergartens in Shanghai, China. Logistic regression model was used to investigate associations.

RESULTS

After adjusted for sex, age, family history of atopy, and questionnaire reporter, the factors which were strongly associated (increased odds >30% and p value <0.05) with lifetime-ever eczema included mother employed during pregnancy (adjusted OR 1.33), residence renovated during pregnancy (1.49) and in the child's first year of life (1.31), using laminate (1.58) and solid (1.42) wood as material of floor covering (compared to using cement), residence located in urban district (1.38), and dampness-related exposures in the early residence (mold spots/stains: 1.41; mold odor: 1.41) and in the current residence (water damage: 1.33; damp stains: 1.34; mold spots: 1.32; and windows pane condensation: 1.31). Parental smoking, pet-keeping, and incense-burning had no significant associations with childhood eczema. Similar associations were found for eczema in the last year before the survey. Families with sick children likely changed lifestyle behaviors and dietary habits.

CONCLUSIONS

Childhood eczema could be influenced by many household environmental and non-environmental factors. Exposures during early lifetime likely have greater impact on childhood eczema than current exposures. Associations of lifestyle behaviors and dietary habits with childhood eczema could be modified by family avoidance behaviors.

Balancing Tolerance or Allergy to Food Proteins

Dietary proteins usually induce immune tolerance, but may trigger life-threatening immune responses in the case of food allergy. The associated type 2 immunity, linked with specific IgE production and the activation of mast cells and basophils, is well understood but the mechanisms related to preventing food allergy are still being deciphered. Recent insights into the mechanisms that regulate oral tolerance and dietary antigen sampling have revealed unique regulatory events that occur during early life and into adulthood. Drawing from both recent clinical and experimental discoveries, this article focuses on current evidence for how several key stages of life present mechanistic points that might participate in tipping the balance between food protein tolerance and allergy.

Gut Microbiome and the Development of Food Allergy and Allergic Disease

The impact of gut microbiome on human development, nutritional needs, and disease has become evident with advances in the ability to study these complex communities of microorganisms, and there is growing appreciation for the role of the microbiome in immune regulation. Several studies have examined associations between changes in the commensal microbiota and the development of asthma, allergic rhinitis, and asthma, but far less have evaluated the impact of the microbiome on the development of food allergy. This article reviews the human gastrointestinal microbiome, focusing on the theory and evidence for its role in the development of IgE-mediated food allergy and other allergic diseases.

Breastfeeding and asthma and allergies: a systematic review and meta-analysis

AIM

To systematically review the association between breastfeeding and childhood allergic disease.

METHODS

Predetermined inclusion/exclusion criteria identified 89 articles from PubMed, CINAHL and EMBASE databases. Meta-analyses performed for categories of breastfeeding and allergic outcomes. Meta-regression explored heterogeneity.

RESULTS

More vs. less breastfeeding (duration) was associated with reduced risk of asthma for children (5-18 years), particularly in medium-/low-income countries and with reduced risk of allergic rhinitis ≤5 years, but this estimate had high heterogeneity and low quality. Exclusive breastfeeding for 3-4 months was associated with reduced risk of eczema ≤2 years (estimate principally from cross-sectional studies of low methodological quality). No association found between breastfeeding and food allergy (estimate had high heterogeneity and low quality). Meta-regression found differences between study outcomes may be attributable to length of breastfeeding recall, study design, country income and date of study inception. Some of the protective effect of breastfeeding for asthma may be related to recall bias in studies of lesser methodological quality.

CONCLUSION

There is some evidence that breastfeeding is protective for asthma (5-18 years). There is weaker evidence for a protective effect for eczema ≤2 years and allergic rhinitis ≤5 years of age, with greater protection for asthma and eczema in low-income countries.

Prevalence of self-reported food allergy in U.S. adults: 2001, 2006, and 2010

BACKGROUND

Epidemiologic evidence indicates that food allergies are increasing in the population. Information on a change in self-reported food allergy (srFA) in adults over time is lacking.

OBJECTIVE

To report the prevalence of srFA and compare differences at three time points over a decade.

METHODS

We analyzed srFA and reported physician-diagnosed food allergy in >4000 U.S. adults who participated in the 2010 U.S. Food and Drug Administration Food Safety Survey. Information on causative food(s), reaction severity characteristics, and various diagnostic factors was also analyzed. We compared 2010 Food Safety Survey data with 2006 and 2001 data, and highlighted relevant differences.

RESULTS

SrFA prevalence increased significantly, to 13% in 2010 and 14.9% in 2006 compared with 9.1% in 2001 (p < 0.001). Physician diagnosed food allergy was 6.5% in 2010, which was not significantly different compared with 7.6% in 2006 and 5.3% in 2001. SrFA increased in both men and women, non-Hispanic white and black adults, 50-59 year olds, and in adults with a high school or lower education. In 2010, milk, shellfish, and fruits were the most commonly reported food allergens, similar to 2001. Also, in 2010, 15% of reactions reportedly required a hospital visit and 8.4% were treated with epinephrine. Minor differences in reaction severity characteristics were noted among the surveys.

CONCLUSIONS

Analysis of survey results indicates that the prevalence of srFA increased among U.S. adults from 2001 to 2010 and that adults are increasingly self-reporting FAs without obtaining medical diagnosis. Improved education about food allergies is needed for this risk group.

Time trends in Australian hospital anaphylaxis admissions in 1998-1999 to 2011-2012

BACKGROUND

Studies from the United Kingdom, the United States, and Australia have reported increased childhood food allergy and anaphylaxis prevalence in the 15 years after 1990.

OBJECTIVE

We sought to examine whether childhood food allergy/anaphylaxis prevalence has increased further since 2004-2005.

METHODS

We examined hospital anaphylaxis admission rates between 2005-2006 and 2011-2012 and compared findings with those from 1998-1999 to 2004-2005.

RESULTS

Overall population food-related anaphylaxis admission rates (per 10(5) population per year) increased from 5.6 in 2005-2006 to 8.2 in 2011-2012 (a 1.5-fold increase over 7 years). The highest rates occurred in children aged 0 to 4 years (21.7 in 2005-2006 and 30.3 in 2011-2012, a 1.4-fold increase), but the greatest proportionate increase occurred in those aged 5 to 14 years (5.8-12.1/10(5) population/y, respectively, a 2.1-fold increase) compared with those aged 15 to 29 years and 30 years or older (a 1.5- and 1.3-fold increase, respectively). Not only did absolute food-related anaphylaxis admissions increase, but the modeled year-on-year rate of increase in overall food-related anaphylaxis admissions also increased over time from an additional 0.35 per 10(5) population/y in 1998-1999 (all ages) to 0.49 in 2004-2005 and 0.63 in 2011-2012 (P < .001).

CONCLUSIONS

Food-related anaphylaxis has increased further in all age groups since 2004-2005. Although the major burden falls on those aged 0 to 4 years, there is preliminary evidence for a recent acceleration in incidence rates in those aged 5 to 14 years. This contrasts with the previous decade in which the greatest proportionate increase was in those aged 0 to 4 years. These findings suggest a possible increasing burden of disease among adolescents and adults who carry the highest risk for fatal anaphylaxis.