Q: Is A2 milk healthier than regular milk?
A: That’s what the ads suggest about this milk, which was developed in New Zealand and is now being produced and sold in California and some other states. But any benefit is hypothetical, since almost all of the research has been done in animals or test tubes, and even that has been inconsistent.
Cow’s milk contains the protein beta-casein, of which there are variants, notably A1 and A2, which are genetically determined. Milk in Western countries usually contains both A1 and A2 proteins; the proportions vary among different breeds of cattle and by geographic location. According to the A2 Milk Company, its milk comes from selected cows whose milk is “certified” as containing only the A2 protein. The company holds patents for genetic testing to see whether cows produce A1, A2, or both.
Proponents of A2 milk claim that the A1 protein, which is more common, causes or contributes to everything from heart disease and diabetes to autism and various psychiatric conditions. The company can’t legally make such unsubstantiated health claims in its marketing material. Instead it makes vaguer claims—that A2 milk is better for people who “have discomfort” after drinking milk and who think they have lactose intolerance but actually have a sensitivity to the A1 protein. And that its milk “naturally supports digestive well-being”—whatever that means. The problem is, there are no independent published clinical trials comparing A2 milk to regular milk to support such claims.
This is an evolving field, and future research may confirm some of the gastrointestinal benefits of A2 milk. Meanwhile, if milk causes you discomfort and you don’t know whether you are lactose intolerant or not, you can see if A2 milk feels better to you. Just be prepared to pay a premium price.
Also see our slideshow 8 Key Facts About Milk.