Infant feeding patterns before and after changes to food allergy prevention guidelines in Australia

Epidemiology and the Growing Epidemic of Food Allergy in Children and Adults Across the Globe

PURPOSE OF REVIEW

Food allergies are immune-mediated, complex disorders, which are the source of increasing health concern worldwide. The goal of this review is to present an updated summary of the food allergy (FA) burden among children and adults across different populations, focusing on research from the past 5 years.

RECENT FINDINGS

FAs impact a growing number of global residents-particularly those residing in higher-income, industrialized regions. Moreover, growing epidemiologic evidence suggests that the population health burden of non-IgE-mediated FAs, such as food protein-induced enterocolitis syndrome, may also be higher than previously reported. FA is a complex trait that impacts infants, children, as well as adults across the globe. The population health burden of both IgE- and non-IgE-mediated FAs is likely to grow in the absence of rapid advances and widespread implementation of effective FA prevention and treatment interventions. Systematic epidemiological research initiatives are needed, both nationally and globally, to better understand and reduce the burden of these allergic diseases.

Revised Swedish infant feeding guidelines are associated with earlier introduction of allergenic foods

BACKGROUND

Randomized controlled trials have demonstrated that early introduction of allergenic foods, such as peanut and egg, can reduce food allergy in high-risk children. Many international guidelines recommend introduction of allergenic foods in the first year of life, and accordingly, the Swedish National Food agency released updated guidelines in June 2019.

OBJECTIVE

Our aim was to examine whether the age at introduction and consumption frequency of allergenic foods have changed since release of the revised national guidelines on the introduction of solid foods in Sweden.

METHODS

Children born between June 2016 and December 2018 (n = 1925) were compared with children born between June 2019 and April 2021 (n = 1761) by using data from the NorthPop Birth Cohort study. Data on food introduction, eczema, and food allergy were prospectively collected until age 18 months by using web-based questionnaires. IgE sensitization was assessed at 18 age months.

RESULTS

The proportion of participants who had been introduced to egg, legume, soy products, peanut, almond, and cashew nut during the first year of life increased after implementation of the revised national guidelines. The most significant changes were seen for legume (from 55.2% to 69.8% [adjusted odds ratio = 1.90 (95% CI = 1.62-2.24)]) and peanut (from 29.2% to 43.2% adjusted odds ratio = 1.87 (95% CI = 1.55-2.24)]); consumption frequency had also increased. No differences in the prevalence of eczema, food allergy, or sensitization to the foods of interest were found.

CONCLUSION

Since release of the revised guidelines, infants in the general population are introduced to and consume a variety of allergenic foods earlier and more frequently; however, early manifestations of allergic disease have remained unchanged.

Rural parents' adherence to infant feeding guidelines to prevent allergy: a cross sectional study in New South Wales

BACKGROUND

Responding to international research showing that early introduction of common food allergens can reduce the chance of developing allergies, in 2016 the Australasian Society of Clinical Immunology and Allergy (ASCIA) revised allergen introduction guidelines, recommending earlier introduction of allergens to infants in their first year. Australia has high food allergy rates, and limited understanding of adherence to allergen introduction guidelines, especially in rural areas. This project explored rural parent adherence to ASCIA guidelines.

METHODS

This was a mixed method cross sectional study using an online survey including multiple-choice and qualitative short answer responses. The sample were 336 women from two rural health districts in New South Wales. All were aged 18 or over, and either pregnant or had delivered a baby since July 2018. Descriptive statistics were used to measure behavioural alignment with the recommended guidelines, thematic analysis was used to analyse attitudes and explanations.

RESULTS

In 84.3% of children, feeding adhered to all four guidelines studied, including no elimination of allergens during pregnancy (98%), age of introduction of solids (97.7%), continuation of breast milk/cow's milk formula during introduction of solids (95%), and age of introduction of allergens (92.9%). Adherence was not significantly correlated with the education (X2 = 17.9, P = .056), prior history of allergy [neither mother (X2 = 0.945,P = .623) nor previous children (X2 = 0.401,P = .818)], or primary care received during pregnancy. More than 90% of participants agreed or strongly agreed that the guidelines are realistic, trustworthy, and important for the health of their child. However, thematic analysis revealed that parents' perceptions of a child's individual progress, and medical conditions or other circumstances, such as challenges with breastfeeding, will often take precedence over adherence to specific guideline recommendations.

CONCLUSIONS

High rates of adherence with ASCIA guidelines found here are comparable with findings from metropolitan studies and encouraging for future population health. Participant comments on the guidelines imply to rural policymakers that there are multiple influences on parent decisions about infant feeding, often including parents' own intuition and experiences. Further studies to improve understanding of the role of information, carers, and other influences on parent decision-making concerning feeding attitudes and behaviours will be necessary to optimise adherence in rural areas.

Early peanut introduction: To test or not to test?

OBJECTIVE

To review recent evidence and international guidelines on early peanut introduction for preventing peanut allergy and provide an update on the status of the debate around testing before early peanut introduction.

DATA SOURCES

Review of published literature documenting: infant feeding guidelines; impact of early peanut introduction on peanut allergy; risk factors for peanut allergy; and impact of early peanut introduction guidelines on infant feeding practices and allergy.

STUDY SELECTION

We used a narrative approach and present both pro and con arguments for testing before peanut introduction. Data from randomized controlled trials and post-hoc analyses of these trials and observational studies were included.

RESULTS

Allergy prevention guidelines around the world now consistently recommend introducing peanut into an infant's diet before 12 months of age for countries with high peanut allergy prevalence. In the US, guidelines recently shifted away from recommending allergy testing before introduction for those at risk of peanut allergy. There is evidence primarily from Australia that recommending early introduction without prior testing is safe and effective in increasing early peanut introduction for both high and low-risk infants, although the subsequent reduction in peanut allergy prevalence at the population level was less than expected.

CONCLUSION

Current evidence supports recommending early peanut introduction without routinely testing for peanut allergy. If testing is offered, this should be based on shared decision making between families and practitioners and only be undertaken where there is provision for rapid access to definitive diagnosis including oral food challenges.

Complementary and Allergenic Food Introduction in Infants: An Umbrella Review

BACKGROUND

Multiple systematic reviews examine the introduction of foods in relation to individual health outcomes, but the balance of harms and benefits has not been overviewed systematically.

OBJECTIVES

We aimed to perform an overview of systematic reviews on age of introduction of complementary and allergenic foods to the infant diet and long and short-term health outcomes.

DATA SOURCES

We searched Medline, Embase, Cochrane, and PubMed (July 25, 2022).

STUDY SELECTION

Included systematic reviews examining the introduction of complementary or allergenic foods before age 1. Outcomes included allergic, autoimmune, and inflammatory diseases, neurodevelopment, nutrition, and weight.

DATA EXTRACTION

Extraction and quality assessment were performed in duplicate (A Measurement Tool to Assess Systematic Reviews) and strength of evidence was assessed.

RESULTS

We screened 4015 articles and included 32 systematic reviews. There was moderate evidence that peanut and egg should be introduced from 4 to 11 months to prevent food allergy (6 of 10 reviews). Complementary food introduction was not associated with food allergy. Moderate certainty evidence suggested age of complementary food introduction was not associated with eczema. Age at introduction of gluten was not associated with celiac disease (high certainty evidence; 3 of 4 reviews). Low certainty evidence indicated that introducing solids before 4 months may increase the risk of childhood obesity, but not growth. There was insufficient evidence regarding an association between any food introduction and bone health, gastrointestinal diseases, autoimmune disorders, asthma, or allergic rhinitis.

LIMITATIONS

Gray literature was not included.

CONCLUSIONS

Current evidence supports introducing complementary foods around 6 months and allergenic foods before 11 months.

Food allergen introduction patterns in the first year of life: A US nationwide survey

BACKGROUND

Prevention guidelines have changed over the past decade and now recommend the earlier introduction of peanut and egg without delaying the introduction of other food allergens. This paper explored caregiver practices regarding the introduction of food allergens during infancy.

METHODS

A survey was administered (2021) to a US population-based sample of 3062 caregivers (children 7 months - 3.5 years). Demographics and feeding practices were collected. Weighted frequencies and proportions were calculated using the svyr package in R 4.1. Survey-weighted chi-square statistics and covariate-adjusted, survey-weighted logistic regression models were used for statistical inference.

RESULTS

Cow's milk, wheat, and soy were the top three allergens introduced. Peanut and egg were introduced by 17.2% and 15.5% of caregivers before 7 months and 58.8% and 66.4% before 1 year, respectively. The age of peanut and egg introduction differed significantly by race/ethnicity (p < .001) and caregiver age (p < .001). Peanut and egg introduction before 7 months was significantly associated with the increased introduction of other allergenic foods before 1 year (p = <.001; peanut and p = < .001; egg). Caregivers who introduced peanut and egg before 7 months infant age fed an additional mean of 5.4 and 4.5 food allergens, respectively, before 1 year. Few caregivers (0.9%) reported feeding an "early food allergen introduction product" ≥ 3 times, which was significantly associated with parental food allergy (OR = 2.2) and previously seen an allergist (OR = 6.7).

CONCLUSION

More than half of the caregivers are not introducing peanut by age of one year and one-third are not introducing egg, though an observed shift toward earlier peanut and egg introduction was seen in the past 5 years. Peanut and egg introduction seem to co-occur and are associated with increased intake of other food allergens.