The new study findings were presented at NUTRITION 2026, the annual meeting of the American Society for Nutrition, adding to its research program focused on naturally occurring beta-casein variants and their potential effects on digestion and health.
According to Bethany Opfer, senior manager of medical marketing at The a2 Milk Company, the findings serve two purposes, including product registration in the US.
“First, these studies were conducted specifically in line with the US FDA’s New Infant Formula Notification (NIFN) registration, which requires infant formula manufacturers to demonstrate that a new formula is non-inferior to commercially available formulas with regard to safety, weight gain and normal physical growth,” she told NutraIngredients.
The a2 Milk Company first launched its infant formula products in the US in 2022 under an expedited process by the US government to address product shortages caused by Abbott’s closure of its Michigan facility, following reports of infant illnesses.
The new study findings also serve to drive future research.
“Second, the findings give us a strong foundation to inform future research, beyond just our US market, particularly the exploratory results on growth, protein efficiency, and gastrointestinal (GI) biomarkers. We see this as a starting point rather than an endpoint, and we’re excited about future opportunities for additional research in infant nutrition,” said Opfer.
In fact, the US market has become a key growth driver, on top of its strong presence in China and Australia.
“Following a year of double-digit growth, The a2 Milk Company is now ranked as the 10th liquid milk brand in the market,” she said. “We’re seeing strong and growing consumer demand for A2-type protein-based dairy in the US, and that momentum is shaping our innovation pipeline as we look at new ways to bring the benefits of a2 Milk to more American households.”
The findings
The Growth Monitoring Study (GMS) is a randomized, controlled, double-blind clinical trial conducted in the US, whereby healthy full-term infants younger than 14 days of age were randomized to receive either A1PF or a conventional formula for 16 weeks.
The primary objective was to determine whether A1PF formula performed comparably to conventional formula in supporting weight gain over the study period.
Between baseline and week 16, infants fed A1PF formula had a mean daily weight gain of 31.94g, compared to 30.15g among infants fed conventional formula. The difference of 1.79g per day exceeded the FDA’s predefined non-inferiority criteria of -3g per day.
Additionally, infants fed A1PF formula remained within the World Health Organization (WHO)-defined healthy growth standards throughout the study.
There were no significant differences between groups for adverse events.
Together, these results indicated that A1PF formula supported appropriate growth and safety within FDA guidelines. Exploratory analyses also pointed to significantly greater average weight (+6%) and length gain (+6.6%) compared to conventional formula.
Furthermore, the preclinical Protein Efficiency Ratio (PER) study examined the protein quality of A1PF formula using an AOAC Official Method, and found favorable results on protein efficiency, antioxidant status and GI biomarkers.
Specifically, infants fed A1PF formula had approximately 11% higher protein-to-growth ratios for weight, compared to infants fed conventional formula.
These findings suggest that the A1PF formula may support more beneficial protein conversion efficiency and represent one of the most rigorous evaluations to date of an infant formula made with A1PF.
Building on two decades of research
Beta-casein is one of the main proteins found in cow’s milk. It naturally exists in two main forms, classified as A1- or A2-type beta-casein. The two differ by a single amino acid, which affects how the proteins are broken down during digestion.
Most infant formulas on the market today for healthy term infants without cow’s milk protein allergy (CMPA) are made with conventional cow’s milk, which contains both A1- and A2-type beta-casein.
Research has shown that milk free from A1-type beta-casein is associated with improved digestive comfort, reduced gastrointestinal symptoms, lower inflammatory markers and higher antioxidant levels, especially in individuals with lactose intolerance. There are also emerging benefits for cognition and quality of life in older adults.
The a2 Milk Company’s A1 Protein Free (A1PF) formula is made with milk containing only A2-type beta-casein and no A1-type beta-casein.
“For more than two decades, the company has invested significantly in in vitro, pre-clinical and clinical studies to bring us to the level of understanding we now have,” said Dr Andrew Clarke, chief scientific advisor at The a2 Milk Company.
Opfer said that as consumer awareness of the differences between A1 and A2 beta-casein continued to grow, infant formula made with A1PF provided another choice for families, including those seeking to incorporate A1PF products in their diet.
