What Foods Have A1 Beta-Casein Protein?

December 31, 2025 •

4 min read

Approximately 80% of the protein in cow's milk is casein, and the A1 beta-casein variant is found in milk from many common Western cow breeds, meaning many everyday dairy products are foods that have A1. This protein is a subject of growing interest for those with digestive sensitivities, prompting questions about its presence in our diet.

Quick Summary

This article explores which dairy products contain A1 beta-casein protein, derived from specific cow breeds. It also clarifies the difference between A1 and A2 milk, details common food sources, and provides information on potential alternatives.

Key Points

Source of A1 Protein: A1 beta-casein protein is primarily found in the milk of specific cow breeds, including Holstein, Friesian, and Ayrshire, which are common in Western dairy farming.
Widespread in Dairy: Most conventional dairy products available in supermarkets, such as milk, cheese, and yogurt, contain A1 protein due to common farming practices.
Digestive Impact: The A1 protein can release a peptide called BCM-7 during digestion, which may cause digestive discomfort in some sensitive individuals.
A2 Alternatives: A2 milk, sourced from specific cows (e.g., Jersey, Guernsey) or other animals like goats and buffalo, contains only the A2 protein and does not form the BCM-7 peptide.
Clear Labeling: To avoid A1 protein, look for products clearly labeled as 'A2 milk' or choose dairy from goat, sheep, or buffalo milk sources.
Not Lactose Intolerance: Sensitivity to A1 protein is distinct from lactose intolerance, which is the inability to digest milk sugar.

Understanding the A1 vs. A2 Protein Difference

To understand what foods have A1, one must first grasp the distinction between A1 and A2 beta-casein proteins. Beta-casein is a major protein in milk, but its composition varies depending on the breed of cow. The A1 beta-casein protein has a different amino acid at position 67 (histidine) compared to the A2 protein (proline), which influences how it is digested. Milk from breeds of Northern European origin, such as Holstein and Friesian, generally contains a mix of A1 and A2 proteins, often with a significant proportion of A1. A2 milk, from breeds like Jersey, Guernsey, and native Indian cows, contains only the A2 protein.

During the digestion of A1 protein, the enzyme cleavage releases a peptide called beta-casomorphin-7 (BCM-7). Some individuals may experience digestive discomfort, such as bloating and stomach pain, due to this peptide. In contrast, the proline in A2 protein inhibits the formation of BCM-7, making it easier for some people to digest. This distinction is crucial for those seeking to manage potential milk sensitivities that are not related to lactose intolerance.

Common Foods Containing A1 Protein

Since most conventional dairy cows in Western countries produce milk with both A1 and A2 proteins, the majority of standard dairy products found in supermarkets will contain A1 beta-casein. This includes both branded and generic products, as commercial dairies typically pool milk from multiple herds that contain A1-producing breeds.

List of Common A1 Dairy Products

Standard Cow's Milk: All varieties—whole, 2%, 1%, and skim milk—that are not specifically labeled as A2 milk.
Cheese: A vast majority of cheese, including cheddar, mozzarella, and cottage cheese, is made from standard cow's milk and will contain A1 protein.
Yogurt: Most regular yogurts, including Greek yogurt, are derived from standard cow's milk and therefore contain A1 beta-casein.
Ice Cream: This frozen dessert is a key product containing A1 protein, as it relies heavily on standard cow's milk and cream.
Butter and Cream: While primarily fat, butter and cream still contain small amounts of casein protein and will likely have A1 protein if sourced from standard milk.
Protein Powders: Whey and casein protein powders derived from conventional cow's milk can be a concentrated source of A1 protein.

How to Identify and Choose Alternatives

For those sensitive to A1 protein, identifying alternatives requires careful product selection. The most direct approach is to seek out products specifically labeled as 'A2 milk' or 'A2 beta-casein'. These are sourced from cows that have been genetically tested to ensure they only produce the A2 protein.

Alternatively, considering dairy from other species can provide a natural A2 source. Milk from goats, sheep, and water buffalo is known to contain predominantly A2-like beta-casein.

Alternatives to A1-Dominant Dairy

A2 Milk: Specifically labeled A2 cow's milk and products are the most direct substitute.
Goat's Milk: Provides a naturally A2-like casein profile.
Sheep's Milk: Another naturally A2-like option, often available in cheeses and yogurts.
Water Buffalo Milk: Traditionally used for cheese like mozzarella, it is also exclusively A2.
Ghee: Clarified butter contains very little protein, so both A1 and A2 ghee are well-tolerated by many with sensitivities.
Plant-Based Alternatives: For a complete dairy-free option, plant milks (almond, soy, oat) do not contain casein at all.

The Difference Between A1 and A2 Dairy Sources

This table outlines the key differences in protein types and common sources for A1 and A2 dairy products, which can help guide dietary choices.


Feature	A1 Milk Sources	A2 Milk Sources
Primary Cow Breeds	Holstein, Friesian, Ayrshire	Guernsey, Jersey, Indian native breeds (Gir, Sahiwal)
Other Animal Sources	Primarily specific European cow breeds	Goats, sheep, water buffalo
Beta-Casein Protein	Contains A1 beta-casein, which can form BCM-7 peptide	Contains only A2 beta-casein, does not form BCM-7
Potential Digestive Impact	May cause discomfort in sensitive individuals	Considered easier to digest for those with milk protein sensitivities
Labeling	Not explicitly labeled, includes most conventional dairy	Often clearly labeled as 'A2 milk' or 'A2 certified'

Understanding Your Sensitivity

It is important to differentiate between A1 protein sensitivity and lactose intolerance. Lactose intolerance is an inability to digest the sugar in milk, while A1 sensitivity relates to the protein component. If you experience digestive symptoms after consuming dairy but a lactose intolerance test is negative, exploring A1 sensitivity by switching to A2 milk or other alternatives may be a useful step. Consulting with a healthcare professional or a registered dietitian is recommended to determine the best course of action for your individual needs. Many individuals have found that switching from conventional milk to A2 milk products or non-bovine dairy provides relief from gastrointestinal issues.

Conclusion

The question of "what foods have A1?" points directly to conventional cow's milk and the vast range of dairy products derived from it. The A1 beta-casein protein, prevalent in milk from certain Western cow breeds, is linked to digestive discomfort for some individuals. By understanding the difference between A1 and A2 proteins and knowing which food sources contain which, consumers can make informed choices. Options like A2-certified products, goat or buffalo milk, or clarified butter offer viable alternatives for those sensitive to A1 protein, without completely eliminating dairy from their diet. For further information on the A1 vs A2 debate and research, the National Food Institute provides valuable insight into milk production and its complexities.

Frequently Asked Questions

A1 and A2 refer to two types of beta-casein protein found in milk. The main difference lies in one amino acid at position 67, which changes how the protein is digested. A1 milk can release a digestive peptide (BCM-7) that A2 milk does not.

Breeds of cows that originated in northern Europe are typically high in A1 protein, and include Holstein, Friesian, and Ayrshire.

Yes, most conventional cheeses and yogurts are made from standard cow's milk that contains a mix of A1 and A2 proteins. To avoid A1, look for products made from A2-certified milk or other animal milk.

No, A1 sensitivity is related to the beta-casein protein, while lactose intolerance is the inability to digest the milk sugar (lactose). Some people with dairy sensitivities who are not lactose intolerant may still experience discomfort from A1 protein.

Good alternatives include A2-certified cow's milk, milk from goats, sheep, or water buffalo, and clarified butter (ghee).

No. While most cows in conventional Western dairy herds produce milk with both A1 and A2 proteins, some breeds, such as Guernsey, Jersey, and indigenous Indian breeds, primarily produce milk with only the A2 protein.

There is no simple home test to differentiate between A1 and A2 milk. Products that contain only A2 protein are generally specifically labeled as 'A2 milk' or 'A2 certified' due to genetic testing of the cows.

It depends on the source. Ghee can be made from either A1 or A2 milk. However, because ghee is clarified butter (primarily fat), it contains very little protein, so even if it's made from A1 milk, it's often well-tolerated by those with A1 sensitivity.