Are the whey and casein proteins in cow’s milk the same as in human milk?

While the whey to casein ratio of Baby’s Only® Organic Gentle Infant Formula and mature breast milk are similar at approximately 60:40, there are differences in the subunits that make up whey and casein proteins. For example, the amount of alpha-lactalbumin (a type of whey protein) in human milk makes up about 22% of the proteins whereas in cow’s milk only 3.5% of the proteins.(1)

Another difference in the proteins is the building blocks called amino acids. Amino acids are what make up proteins. The types and amounts of amino acids in human milk proteins are different than those found in cow’s milk.

Regardless of these differences, formulas made with cow’s milk have been researched for decades and have consistently been shown to support a child’s growth and development.


  1. Layman DK, Lönnerdal B, Fernstrom JD. Applications for α-lactalbumin in human nutrition. Nutr Rev. 2018;76(6):444-460. doi:10.1093/nutrit/nuy004
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