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.
BACKGROUND & OBJECTIVE: It has been suggested that prenatal vitamin D plays a role in the development of childhood asthma and wheeze. Several systematic reviews have been conducted, but the results are inconsistent, and the methodological quality has not been studied. Therefore, the objective of this umbrella review was to assess the internal validity of the evidence base and the evidence for an association between prenatal vitamin D and asthma or wheezing in the offspring.
METHODS: We searched the electronic databases Embase, PubMed, and Cochrane Library for studies on prenatal vitamin D using search words such as vitamin D, 25-hydroxyvitamin D, calcidiol, fetal, and neonatal. The search was conducted in June 2020, and the databases were searched from their date of establishment. We included systematic reviews and/or meta-analyses of experimental and observational studies assessing the association between prenatal vitamin D or asthma and wheeze. We excluded narrative reviews, commentaries, and other umbrella reviews. The methodological quality of systematic reviews was assessed using AMSTAR 2 tool. PROSPERO reg. no. CRD42020151329.
RESULTS: We identified 22 eligible systematic reviews (17 on asthma and 20 on wheeze). Using the AMSTAR 2 quality assessment tool, the methodological quality was rated as critically low in 21 out of 22 systematic reviews, suggesting that previous reviews and meta-analyses did not provide accurate and comprehensive summaries of the included studies and that conclusions reached were potentially flawed. The majority of the included reviews reported that prenatal vitamin D reduces the risk of wheeze in the offspring.
CONCLUSION: Prior to informing public guidelines, high-quality systematic reviews of the current evidence are greatly warranted.
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.
