Which milk is better for you? Cow’s milk or soy milk?

Last updated 17/01/2024

Cow's milk offers many health benefits and contains a package of readily absorbed nutrients that are hard to replicate. Soy milk does not have the same body of evidence to support similar health benefits and some people don't like the "beany" flavour of soy milk.¹

Whilst soy milk has similar amounts of protein to cow's milk ², the type of protein in cow's milk is of a higher quality compared to soy milk, which means it contains all the essential amino acids that our bodies need. Soy milk on the other hand is lower in the amino acid leucine, which our bodies need to build muscle and prevent muscle breakdown.³ The protein in cow's milk has also been shown to be more bioavailable, which refers to how well it can be digested and absorbed in the body.⁴

Many soy milk varieties have added calcium to achieve similar amounts as naturally found in cow's milk. However, even with fortification, the body does not absorb the calcium in soy milk as well as it does the calcium in cow's milk.⁵ In addition, soy milk contains less phosphorus, riboflavin, vitamin A and zinc compared to cow's milk.²

Soy milk can be a suitable choice for people who have been diagnosed with a cow's milk allergy and advised by their health professional to switch to soy. However, for the general population, cow's milk offers more nutrition and greater health benefits compared to soy milks, especially when consumed everyday as part of a healthy, balanced diet.