What is A1 Free Dairy? Understanding A2 Milk for Better Digestion

December 19, 2025 •

2 min read

A genetic mutation that occurred thousands of years ago in dairy cattle caused a change in milk protein, leading to the creation of both A1 and A2 beta-casein. A1 free dairy, often called A2 milk, is milk that exclusively contains the ancestral A2 protein.

Quick Summary

A1 free dairy, commonly known as A2 milk, is milk containing only the A2 beta-casein protein from specially selected cows, offering a gentler digestion for some individuals.

Key Points

Protein Difference: A1 free dairy, or A2 milk, contains only the A2 beta-casein protein, whereas conventional milk has both A1 and A2 variants.
Easier Digestion: For some individuals with milk sensitivity, A2 milk is easier to digest because it doesn't release the potentially inflammatory peptide BCM-7.
Genetic Origin: A2 is the original milk protein, while the A1 variant appeared as a natural genetic mutation over time in some European cow breeds.
Not for Allergies: A1 free dairy is not a solution for true lactose intolerance or a diagnosed milk allergy, as it still contains lactose and milk proteins.
Purity Assured: A1 free milk is produced through genetic testing and selective breeding of A2-only cows, with milk batches tested to confirm purity.
Ongoing Research: The scientific community continues to investigate the long-term health implications and benefits of A2 milk versus A1 milk.

The Difference Between A1 and A2 Beta-Casein Protein

The key difference between A1 and A2 dairy lies in a slight variation in the beta-casein protein, which makes up about 30% of milk's total protein. A2 beta-casein has proline at position 67 of its amino acid chain, while A1 beta-casein has histidine.

This small change affects digestion. When A1 protein is digested, it can release beta-casomorphin-7 (BCM-7), a peptide linked to potential gastrointestinal discomfort often mistaken for lactose intolerance. A2 milk's structure with proline at position 67 prevents the release of this peptide, potentially leading to easier digestion for some.

The Origins of A1 and A2 Milk

Originally, all cows produced milk with only A2 beta-casein, similar to other mammals. The A1 variant is thought to be a mutation that spread in European dairy breeds like Holstein and Friesian. Many modern herds produce milk with both proteins, while ancient breeds like Guernsey and Jersey tend to produce milk high in A2.

The Production of A1 Free (A2) Milk

A1 free dairy is produced by selecting cows that naturally produce only the A2 protein. This involves genetic testing to confirm cows carry the A2 gene, selective breeding, herd separation, and milk testing to ensure the final product is only A2.

Potential Benefits and Individual Tolerance

For individuals with digestive discomfort after drinking conventional milk, A1 free (A2) milk may help. Some research suggests it can reduce gastrointestinal issues and inflammation possibly due to less BCM-7 production.

It is important to understand that A1 free dairy does not treat lactose intolerance or milk allergies. Lactose intolerance is about sugar digestion, and milk allergies are an immune response to proteins. A2 milk still contains lactose and other proteins. Trying A2 milk to see if symptoms improve is one way individuals can assess if A1 protein sensitivity is an issue.

A1 vs. A2 Milk: A Side-by-Side Comparison


Feature	A1 Milk	A2 Milk (A1 Free)
Beta-Casein Protein	Contains A1 and A2 protein variants	Contains only the A2 protein variant
Origin	Predominantly from modern European cow breeds (Holstein, Friesian)	From ancient cow breeds (Jersey, Guernsey, Indian breeds)
Digestion	Can release BCM-7 peptide, potentially causing discomfort	Releases little to no BCM-7 peptide
Potential Effects	Linked to digestive issues and inflammation in sensitive individuals	Generally considered easier on the digestive system
Protein Structure	Histidine at position 67	Proline at position 67

Conclusion: Making the Right Dairy Choice

A1 free dairy is gaining recognition as a potential option for those with milk protein sensitivities. While research continues, trying A2 milk may help individuals enjoy dairy without discomfort. It is always recommended to consult a healthcare provider for any digestive concerns or suspected food intolerances or allergies.

Frequently Asked Questions

No. A1 free dairy addresses sensitivity to the A1 beta-casein protein, not lactose. It contains the same amount of lactose as conventional milk and is not suitable for those with diagnosed lactose intolerance.

BCM-7 is a peptide released during the digestion of A1 beta-casein. Some research suggests it can cause digestive discomfort, inflammation, and other issues in certain sensitive individuals, unlike the digestion of A2 beta-casein.

A1 free milk is produced by genetically testing dairy cows to identify those that naturally produce only the A2 protein. These cows are then kept in separate herds, and their milk is collected and processed separately.

While many ancient breeds and indigenous cattle, such as Jersey, Guernsey, and Indian breeds like Gir, are naturally high in A2 protein, modern A1 free dairy comes from genetically tested cows of any breed.

No. A2 milk will not cure lactose intolerance. However, if your symptoms are related to sensitivity to the A1 protein rather than lactose, you may find A2 milk easier to digest.

Current studies have not highlighted any specific risks associated with consuming A2 milk. However, it is not suitable for individuals with a milk allergy.

The only way to know for sure is through a proper medical diagnosis. However, many people try switching to A2 milk to see if their symptoms improve, which can help determine if A1 protein sensitivity is the cause.