An animal study conducted at the Nestle Research Center in Lausanne, Switzerland, found that using modified protein fractions in infant formulas to mimic human milk does not improve protein uptake or mineral bioavailability. The findings were published in the Journal of Nutrition (135:1438-43, 2005).
Rats were divided into four groups and fed diets containing 10% protein as casein, beta-casein, a 40-to-60 casein-to-whey ratio, or a 40-to-60 beta-casein-to-alpha-lactalbumin ratio. Animals on whey-containing diets showed greater protein utilization and body weight gain compared to those on casein diets, but there were no differences between the two casein groups or the two whey groups. Similarly, whey diets enhanced the absorption of minerals such as calcium, iron, and zinc compared to casein diets, but no apparent benefits were observed from using casein or whey protein fractions.
