Hydrolyzed formulas (HF) are used presently primarily in infants that cannot be exclusively breastfed, those with cow’s milk allergy, and in some countries for primary prevention of allergic disease, but HFs are increasingly being used worldwide, begging the question if they may be recommended as the optimal choice for all standard-risk, full-term, non-exclusively breastfed infants.
Data regarding the nutritional adequacy of modern-day HFs are scarce and lack long-term data suggesting that growth in infants fed HF versus an intact protein formula is different. While human breast milk is the optimal source of nutrition for multiple reasons, a 2006 systematic review determined there were no comparable long-term studies regarding prolonged use of HFs versus breastfeeding. Meta-analyses of formula consumption and risk of atopic dermatitis (AD) have been conflicting; some have found that infants fed partially HF compared to IPF had a lower risk of AD, but there are significant limitations to these studies, making conclusions about the general use of HFs problematic.
Because of the paucity of data, more studies are needed to investigate routine use of HF as an equivalent to option to breastfeeding and the feasibility of HF as a routine feeding option for healthy, standard-risk infants. Despite the issues raised here, the desire to provide concrete recommendations of widespread HF use need to be balanced carefully in order to not overstate claims of benefit.