Does Organic Milk Contain A1 Protein? Uncovering the Truth

October 29, 2025 •

3 min read

The protein beta-casein, found in cow's milk, exists in different genetic variants, primarily A1 and A2. So, does organic milk contain A1 protein? The simple answer is that the "organic" label does not determine the protein type; it depends entirely on the cow's genetics, meaning organic milk can contain A1 protein just like conventional milk.

Quick Summary

The presence of A1 protein in milk is determined by the cow's breed, not by its organic certification. This means organic milk can contain both A1 and A2 beta-casein protein variants, unlike specialized A2 milk products.

Key Points

Organic Doesn't Mean A1-Free: An organic certification relates to farming practices, not the cow's genetics, so it can contain A1 protein.
Genetics are the Key: The presence of A1 protein is determined by the specific beta-casein genes of the cow, which vary by breed.
A1 vs. A2 Digestion: A1 protein releases a peptide (BCM-7) during digestion that can cause discomfort in some individuals, which does not happen with A2 protein.
Look for the 'A2' Label: To avoid A1 protein, consumers must purchase milk explicitly labeled as "A2 milk," which is sourced from genetically tested herds.
Organic A2 Milk Exists: Some brands combine organic farming methods with A2/A2 cow genetics, offering an organic, A1-free product.
Breed Matters: Breeds like Holstein are more likely to produce A1 protein, while older breeds such as Jersey and Guernsey are more likely to produce A2.
Potential Digestive Benefits: Some people who experience dairy-related digestive issues find relief by switching to A2 milk, as it may be easier to digest.

Understanding the A1 vs. A2 Beta-Casein Protein

To answer the question of whether organic milk contains A1 protein, it's crucial to first understand the nature of A1 and A2 proteins. Both are variants of beta-casein, which makes up about 30% of the total protein in cow's milk. The difference lies in a single amino acid at position 67 of the protein chain. A1 protein has a histidine amino acid at this position, while A2 has a proline. This seemingly small difference has a significant impact on how the protein is digested in the human body. When A1 protein is broken down, it releases a peptide called beta-casomorphin-7 (BCM-7), which some research suggests may cause digestive discomfort in some individuals. A2 protein, on the other hand, does not release this peptide during digestion.

The Role of Genetics, Not Farming Methods

This genetic difference is the key factor, not the farming practices. Organic milk comes from cows raised on organic feed with outdoor access and no artificial growth hormones or antibiotics. The organic certification governs the animal husbandry and feeding process, but it does not alter the cow's inherent genetic makeup. Therefore, an organic cow can have the genetics to produce milk with A1 protein, A2 protein, or a mixture of both. The A1 variant arose from a natural genetic mutation that spread through dairy herds over time, especially in breeds originating from northern Europe, like Holstein and Friesian cows.

Breeds and Protein Types

Different breeds of dairy cows have a higher probability of producing one protein type over the other. For instance, many modern breeds like Holsteins are more likely to have the A1 gene, while older, more traditional breeds, such as Jerseys, Guernseys, and certain Indian breeds (like Gir and Sahiwal), have a higher frequency of the A2 gene.

How to Ensure A1-Free Milk

For consumers seeking to avoid A1 protein, simply buying organic milk is not enough. The only way to ensure the milk is free of A1 protein is to purchase a product specifically labeled as "A2 milk". Brands producing A2 milk genetically test their cows and separate herds to ensure the milk contains only the A2 beta-casein protein.

Characteristics of A1 vs. A2 Milk

A1 Milk: Derived from cow breeds like Holstein and Friesian; releases BCM-7 peptide upon digestion; may cause digestive issues for some individuals.
A2 Milk: Derived from cows like Jersey, Guernsey, and native Indian breeds; does not release BCM-7; may be easier to digest for some.
Organic Milk: Farming method, not protein type; can contain A1 or A2 proteins depending on the cow's genetics.


Feature	Organic Milk (Generic)	A2 Milk (Organic or Conventional)
A1 Protein	Can contain A1 (depending on breed)	Does not contain A1 protein
A2 Protein	Can contain A2	Contains only A2 protein
Farming Method	Must adhere to organic standards	Can be either organic or conventional
Genetic Basis	Determined by the cow's genetics	Sourced from cows with specific A2/A2 genetics
Digestive Impact	Varies, can be difficult for some	May be easier on digestion for sensitive individuals

Making an Informed Choice

If you experience digestive discomfort after consuming regular dairy but are not clinically lactose intolerant, switching to A2 milk might be a viable option. Some people find relief from bloating and other symptoms by making this change. It's a common misconception that the organic label offers a solution for this particular protein sensitivity, but as we've explored, the issue is genetic, not related to the organic nature of the farming.

Conclusion

In conclusion, whether organic milk contain A1 protein depends on the genetic background of the cows that produced it, not the organic certification itself. While the organic label guarantees certain farming practices, it does not promise the absence of A1 beta-casein. Consumers who are concerned about A1 protein should actively seek out products specifically labeled as "A2 milk" to ensure they are buying milk from genetically selected herds that produce only the A2 beta-casein variant. This understanding empowers consumers to make an informed choice based on their individual digestive needs and preferences. For more information on the A1 vs A2 distinction, visit the a2 Milk Company website(https://a2milk.com.au/A1-protein-free-explained).

Frequently Asked Questions

A1 and A2 are different genetic variants of beta-casein, a protein found in milk. The primary difference is a single amino acid that affects how the protein is digested, with A1 potentially releasing a problematic peptide.

The term 'organic' refers to farming methods, such as feed and living conditions, not the cow's genetic makeup. The presence of A1 or A2 protein is determined by the specific breed of cow, regardless of whether it was raised organically or conventionally.

Older, heritage cow breeds like Jersey and Guernsey, as well as native Indian breeds such as Gir and Sahiwal, are more likely to naturally produce only A2 milk. Modern breeds like Holstein are more commonly associated with the A1 protein.

No, it is not possible to tell if milk is A1 or A2 by its taste, smell, or appearance. Determining the protein variant requires specialized lab testing or knowledge of the cow's genetics.

No, A2 milk contains lactose just like regular cow's milk. A2 milk addresses sensitivities related to the A1 beta-casein protein, which is separate from lactose intolerance.

Brands that sell A2 milk genetically test their dairy cows to identify those with the A2/A2 gene variant. These cows are then separated into dedicated herds to ensure that their milk contains only the A2 beta-casein protein.

If you experience digestive issues with regular milk, it may be worth trying A2 milk, especially if you are not clinically lactose intolerant. For some, switching to A1-free milk can help reduce symptoms of bloating and discomfort.