An organic jersey cow

You may have seen a label becoming more common on your dairy shelves: A2 milk. What is A2 milk, and why do some people claim that it solves gastrointestinal issues they otherwise get from dairy?

A2 isn’t really new. In fact, it’s been around for as long as humans have been drinking milk.

The difference in A2 milk comes down to its nutritional profile. There are two major types of protein in cows’ milk. Casein and whey account for approximately 82% and 18%, respectively, of the protein. Beta-casein is the second most abundant protein in cows’ milk, making up about a third of the caseins. A1 and A2 are two variants of beta-casein.

The genetic profile of individual cows determines the beta-casein. It’s believed that A1 is a natural genetic mutation that occurred in Europe around the time of domestication — prior to that, all milk was A2. The only way to know whether a cow produces A2 versus A1 milk is through genetic testing, although historical breeding practices have resulted in trends in various breeds.

Dairy products with A1 beta-casein are most prevalent in the US and Europe. Cattle in Africa, India, and other areas of Asia produce predominantly A2 beta-casein. In the US, certain breeds of cattle, including Jerseys and Guernseys, are more likely to produce A2 beta-casein milk. However, the predominant breed of cattle used in commercial milk production is the Holstein, which historically has not been selected for A2 genetics, leaving A1 in much of the domestic supply.

Human health considerations

Some individuals find that consuming A1 milk results in reactions that can resemble lactose intolerance, such as pain, bloating, and other discomfort. Those experiences are backed up by studies showing that A1 beta-casein may cause more gastrointestinal inflammation than A2 beta-casein.

A2 beta-casein may be easier to digest and more “familiar” to the general human population than A1, which came on the evolutionary scene relatively late and was generally a feature of European herds. While research is ongoing, studies show varying digestive effects of the two beta-caseins in different populations and dietary settings. Anecdotally, many dairy consumers find that consuming A2 dairy products improves digestive discomfort that they may have wrongfully attributed to lactose intolerance or allergy.

Those with a dairy allergy are less likely to benefit from A2 milk (and it is riskier to experiment). Unlike a sensitivity, response to inflammation, or inability to digest a compound, an allergy triggers an immune response to one of the compounds in milk. The most frequent symptoms with a cows’ milk protein allergy are also gastrointestinal, but can be varied and even life threatening.

Every individual has different health needs. Some people will tolerate A1 milk just fine, while others may find their bodies prefer A2 milk. Still others, whether sensitive or allergic, will not be able to tolerate dairy at all.

Good news for consumer choice

As awareness about A2 milk grows, the marketplace has responded. More and more farmers are genetically selecting for cattle that only produce the A2 beta-casein. While some commercial-scale A2 milk brands exist, many small dairies are slowly converting their breed to A2. Some of these producers are also certified organic, affording benefits beyond casein type.

As detailed in Cornucopia’s report, The Industrialization of Organic Dairy: Giant Livestock Factories and Family Farms Sharing the Same Organic Label, organic milk produced by community-scale farmers has a myriad of benefits. Use our Organic Dairy Scorecard to find brands you can trust, and choose local organic if you’re fortunate enough to have one of these operations in your region.

For a deeper dive into A2 milk, read our summary of the research.

Where to Find Organic A2

The following certified organic brands from Cornucopia’s Organic Dairy Scorecard sell A2 dairy products. To learn more and see the overall rating of each brand, visit our Organic Dairy Scorecard.

Alexandre Family Farms: milk, cream, eggnog (seasonal), yogurt
Chaseholm Farms: more information available on their website.
Dutch Meadows Farm: yogurt
Kirkland Signature: milk
Nature’s Promise: milk
Pavel’s Yogurt: yogurt
Pride and Joy Dairy: milk, cheese
Radiance Dairy: Currently converting to A2
Saint Benoit Creamery: milk
Spring Wood Organic: more information available on their website.
Trader’s Point Creamery: more information available on their website.
Trimona Yogurt: milk
Westby Coop Creamery: cheddar cheese (note: the specific product from this brand is not organic)
Working Cows Dairy: more information available on their website.

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