Allergy prevention: Exclusive breastfeeding advisable, hydrolyzed formulas may be considered
Exclusive breastfeeding for 6 months is advisable for allergy prevention, while hydrolyzed formulas (HFs) with reduced allergenicity may be considered for mothers who are unable or choose not to breastfeed, an expert recommended.
“There has been a lot of interest in the role of human milk oligosaccharides [HMOs] in allergy prevention,” said Professor Hania Szajewska of the Department of Paediatrics, Medical University of Warsaw, Poland. “While evidence for the role of breastfeeding in allergy prevention has been inconsistent due to issues with study design and inter-individual variability in HMO composition, the European Food Safety Authority and US FDA have confirmed the safety of two HMOs, added alone or in combination, to infant, follow-on or young-child formulas.”
The latest evidence supporting the role of HMOs in allergy prevention came from a study in 421 mother-infant pairs from the CHILD (Canadian Healthy Infant Longitudinal Development) cohort. “Overall, 14 percent of infants displayed food sensitization at 1 year of age,” said Szajewska. “No significant associations were found for the 19 individual HMOs or total HMOs with food sensitization. However, overall HMO profiles differed significantly between infants with and without food sensitization. A specific profile of HMOs was found to be associated with a lower rate of food sensitization.” [Allergy 2018, doi: 10.1111/all.13476]
“The findings indicate a possible role for HMOs in allergy prevention, especially since certain HMOs can now be added to infant formulas,” she suggested. “While further studies are needed, it would be desirable to advise exclusive breastfeeding in all infants for about 6 months.”
For mothers who cannot or choose not to breastfeed, HFs with proven reduction in allergenicity may be considered, Szajewska advised.
“A meta-analysis in 2016 found no consistent evidence to support the use of HFs for prevention of allergic diseases, because various types of partially HFs [pHFs] and extensively HFs [eHFs] and studies with different designs were pooled together,” she noted. [BMJ 2016;352:i974]
“Not all HFs provide the same degree of protective benefit. Factors such as the protein source and method and degree of hydrolysis contribute to differences among hydrolysates. As such, the efficacy and safety should be established for each HF,” she emphasized. [Pediatrics 2008;121:183-191]
In a more recent meta-analysis, Szajewska and colleagues evaluated the effect of a 100 percent whey pHF vs cow’s milk in reducing the risk of allergic diseases. Results showed a significantly reduced risk of eczema at some time points. [World Allergy Organ J 2017;10:27]
“While discussion on the role of HFs in allergy prevention continues, the use of pHFs is shown to be cost-effective for prevention of atopic dermatitis or eczema,” said Szajewska. [Ann Nutr Metab 2011;59(Suppl 1):44-52; Pediatr Allergy Immunol 2012;23:597-604; J Med Econ 2012;15:1064-1077]
“Based on evidence from recent randomized controlled trials, the European Society for Paediatric Gastroenterology Hepatology and Nutrition recommended that allergenic foods may be introduced when complementary feeding is commenced any time after 4 months of age. Infants at high risk of peanut allergy should have peanuts introduced at 4–11 months of age following evaluation by an appropriately trained specialist,” she added. [J Pediatr Gastroenterol Nutr 2017;64:119-132]