Adequacy and safety of α-lactalbumin-enriched low-protein infant formula: A randomized controlled trial.

Objectives: The aim of this study was to demonstrate suitability and safety of an infant formula enriched with α-lactalbumin with a reduced protein content of 1.89 g protein/100 kcal.

Methods: This was a randomized, double-blind controlled trial with 80 healthy newborn infants who were assigned to receive either an isocaloric low- or high-protein content formula (1.89 versus 2.1 g/100 kcal). The low-protein content formula was enriched with α-lactalbumin. A breast-fed reference group of 40 infants was studied concurrently. Anthropometric measures were taken at inclusion, after 6 and 12 wk as well as after 6 and 12 mo of follow-up. Primary outcome was weight gain in g/d between study inclusion to 12 wk. Secondary outcomes included anthropometric measures expressed in Z-scores, mean formula consumption, and caloric intake as well as food tolerance.

Results: Fifty-two infants in the formula group (low protein: 26, high protein: 26) and 32 in the breast-fed reference group completed the 3-mo intervention period. There was no difference in weight gain among feeding groups at the end of the intervention period. Mean weight gain in g/d was 32 in the low-protein, 31 in the high-protein, and 33 in the breast-fed reference group. No significant difference was found between study groups in Z-scores for weight, length, head circumference, weight-for-length, or body mass index nor for fat percentage at end of intervention and after follow-up.

Conclusion: α-lactalbumin-enriched formula with a protein content of 1.89 g protein/100 kcal is safe and supports adequate growth.