GASTROINTESTINAL (GI) TOLERANCE OF ALPHA-LACTALBUMIN ENRICHED FORMULA SIMILAR TO THAT OF HUMAN MILK

A new study¹, published in July in the European Journal of Clinical Nutrition, gives new insights into the optimal concentration of proteins in infant formula. The study found that the GI tolerance profile of infants fed with an alpha-lactalbumin-enriched infant formula is similar to that of infants fed with breast milk. In addition, the study found that this higher quality, lower protein concentration formula meets all essential amino acid and protein requirements for infants. 

The study was conducted to evaluate the efficacy and safety of an alpha-lactalbumin-enriched formula with a protein profile and total protein concentration closer to that of breast milk. 216 term infants were enrolled and 166 completed the study. Essential amino acid levels were determined after eight weeks and study events were assessed every two weeks.

At 8 weeks, all mean plasma essential amino-acid levels in the alpha-lactalbumin-enriched formula group (EF) were as high as the standard formula (SF) and breast /human milk groups (HM). The incidence of feeding-related GI events, including constipation and regurgitation, varied significantly (P=0.025) across the groups: SF (31.3%), EF (17.2%) and HM (13.6%), with SF being significantly higher than HM (P=0.015). Study withdrawals due to feeding-related GI events were significantly different (P=0.001) across groups: SF (12.5%), EF (4.7%), and HM (0%).

The study investigators concluded that feeding a higher quality, lower protein concentration formula (alpha-lactalbumin-enriched) met all essential amino acid and protein requirements for infants. At the same time, the GI tolerance profile of infants receiving the EF was similar to HM-fed infants.

Commenting on the study paper, Nutritionist and SMA Nutrition Communications Manager Yvonne McCallum said, “Here at SMA we’re dedicated to research into infant formula, with the goal of designing formulas that mimic breast milk composition and physiologic effects as far as possible. Traditionally, infant formulas contained a higher protein concentration than breast milk to provide formula-fed infants with sufficient quantities of essential amino acids. Numerous studies have evaluated formulas with lower protein / energy ratios, but the results showed lower plasma tryptophan levels, and thus unsuitability for infants. We’re therefore really excited about the present study, where sufficient essential amino acids such as tryptophan was provided in a lower protein formula (EF) via enrichment with the protein a-lactalbumin.”

In addition to lowering the protein concentration of EF closer to that of HM, the enrichment of infant formula with the whey protein a-lactalbumin results in a whey protein composition closer to that of HM (alpha-lactalbumin is the dominant whey protein found in breast milk whilst beta-lactoglobulin, which is not normally found in breast milk, is the dominant whey protein in cows’ milk). HM whey proteins play an important role in many physiologic activities that benefit the infant such as immune function and nutrient absorption.

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For further information contact the Red Consultancy:
• Katherine Murphy, Katherine.murphy@redconsultancy.com
020 7025 6547
References
1. Davis AM et al. a-Lactalbumin-rich Infant formula fed to healthy term Infants in a Multicenter Study: Plasma Essential Amino Acids and Gastrointestinal Tolerance. European Journal of Clinical Nutrition, Advance online publication 25th July 2007.
http://www.nature.com/ejcn/journal/vaop/ncurrent/full/1602848a.html#bib31  
Last accessed March 2008.