Milk introduction before the age of 6 months and the risk of milk allergy
Level of evidence: D
Milk introduction before 6 months of age may have little or no effect on the risk of milk allergy, but the evidence is very uncertain.
Due to low evidence certainty, it is difficult to estimate potential absolute benefits from early milk introduction. In a systematic review of early food introduction, half of the trials compared cow's milk formulas to milk-free formulas. By excluding the formula trials, pooled event rates were 6/1575 in the intervention group and 13/1602 in the control group, suggesting a small benefit, but event rates are very small «Scarpone R, Kimkool P, Ierodiakonou D, ym. Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis. JAMA Pediatr 2023;177(5):48»1. A meta-analysis of 11 studies suggested a small to no impact on study withdrawals, RR 1.05 (95% CI 0.61-1.82) «Scarpone R, Kimkool P, Ierodiakonou D, ym. Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis. JAMA Pediatr 2023;177(5):48»1.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| SR=systematic review; MA=meta-analysis | |||||
| «Scarpone R, Kimkool P, Ierodiakonou D, ym. Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis. JAMA Pediatr 2023;177(5):48»1 | SR and MA | Infants 3-6 months old. Both low and high risk populations. | Early milk introduction vs placebo, milk-free formula or no intervention (in control group milk was introduced at 8 months or later) | Milk allergy: double-blind, placebo-controlled food challenge; open food challenge; medical diagnosis at 6-36 months. | moderate |
| Reference | Comments |
|---|---|
| «Scarpone R, Kimkool P, Ierodiakonou D, ym. Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis. JAMA Pediatr 2023;177(5):48»1 | Of six trials, three compared milk formula vs milk-free formula. The remaining trials compare early cow's milk introduction at age of 3-4 months to introducing milk at six months of age (2 trials) or at 8 months (1 trial). One of the six trials had placebo control. Of the six trials, two were considered to be at low risk of bias by the review authors. |
Results
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (%) I | Absolute number of events (%) C | Relative risk (95% CI) |
|---|---|---|---|---|---|
| I= intervention; C=comparison; CI=confidence interval | |||||
| «Scarpone R, Kimkool P, Ierodiakonou D, ym. Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis. JAMA Pediatr 2023;177(5):48»1 | 6 | 6-36 months | 25/1944 | 25/1956 | 0.84 (0.38-1.87) |
| Level of evidence: very low The level of evidence was rated down for risk of bias, indirectness, and imprecision. | |||||
References
- Scarpone R, Kimkool P, Ierodiakonou D, ym. Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis. JAMA Pediatr 2023;177(5):489-497 «PMID: 36972063»PubMed