A1 vs. A2 Milk? What's the Difference? Is A2 "Healthier"?

Difference between A1 and A2 dairy. There are two main categories of milk protein —> casein & whey. Exploring casein —> think of this protein as a large family, consisting of several ‘types’ of relatives (different caseins), and each ‘relative’ has it’s own composition, genetic variation, and functional properties. This is the relationship between 🔶A1 and 🔷A2 protein —> they are two variants within the beta-casein family. View the image below for the main sources of A1 and A2.

Why the difference? —> Some 5000 years ago, a mutation occurred on the 67th amino acid converting it from proline to histidine. Cows🐄 that have this mutated beta-casein are called A1 cows, which include most ‘newer’ Western breeds. Most bovine milk contains both A1 & A2 at different concentrations, while sheep 🐑goat🐐 & buffalo are A2. Note: total milk protein content and amino acid composition varies with cow breed & individual animal genetics, so while most cow milk we see today is A1, it can be A2. Now that we understand where the difference between A1 and A2 comes from on a basic level, what does this mean for us? Let's explore why some people claim A2 is ‘healthier’.


So what’s the beef with A1? Do the studies support that A2 is healthier? View the image below for adverse health effects linked with consumption of A1 dairy. However, the studies that link A1 with adverse health effects in humans are largely epidemiological. While conclusive statements are not typically made from observational data, we shouldn’t completely ignore the data. But, more clinical trials with human subjects should be performed to further investigate the relationship between A1 & human health.


Just like raw versus pasteurized milk, some people with allergies find they can tolerate A2 dairy and not A1, so A2 could be worth a try if you struggle with *raw* A1 dairy. But this makes us even more curious about the difference in health risks between *raw* A1 & processed A1 dairy. Would we see the same link? Whether A1 or A2, more on choosing a quality raw milk farmer here.


Below, you’ll find more posts in the dairy series. Read about…

The evolution of dairy & dairy intolerance

Difference between raw, pasteurized, & homogenized dairy

Why drink raw milk: benefits of & nutrients

Origins of pasteurization & the war against raw milk

Safety of Raw Milk?

A1 vs. A2 milk? Is A2 healthier?

Raw dairy farmers: how to find raw dairy & what to ask your farmer

Should you eat raw dairy on carnivore? How to test for dairy intolerance


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