We’re sometimes asked whether our whey protein comes from A2 cows. While it’s a common query, when it comes to whey protein, the distinction between A1 and A2 cows – to our knowledge – isn’t actually relevant.

In this guide, we wanted to break down the facts behind A1 and A2 milk proteins, focusing on what’s relevant when choosing the right protein powder to suit your health goals and dietary requirements.

Casein forms 80% of the protein content in milk, with whey making up the remaining 20%. There are several different types of casein in cow’s milk, but beta-casein is the second most prevalent. (1) 

A1 and A2 are two types of beta-casein proteins found in cow’s milk. A1 and A2 beta-casein are both naturally occurring forms, but they differ in their amino acid composition. (2)

Most commercial cow’s milk – in the UK, this is generally A1 milk – contains a mix of both A1 and A2 beta-casein. A2 milk, on the other hand, is sourced from specific cow breeds such as Jersey, Guernsey, and some other heritage breeds which produce A2 milk and milk proteins exclusively.

What’s the difference between A1 and A2 milk proteins?

The distinction between A1 and A2 proteins lies in a small structural difference in their amino acid chains. Where A1 beta-casein has histidine, A2 beta-casein has proline. (3)

A1 protein may release a peptide called beta-casomorphin-7 (BCM-7) during digestion (4), which some researchers believe could contribute to digestive discomfort in certain individuals. (5) This has led to the belief that the proteins from A2 milk may be easier to digest for some people, particularly those with dairy sensitivities. However, it’s a hypothesis that’s still under review.

While these studies are ongoing, A2 milk has gained popularity as a potentially gentler option. However, it’s important to note that these differences apply to casein, not to whey protein.

While A1 proteins have been in the spotlight due to their potential impact in areas such as digestion (6,7), type 1 diabetes, (8) and heart disease (9) amongst others, it is only casein that is categorised as either A1 and A2 protein, not whey protein, which remains unaffected whichever form of casein is present in the milk.

From what we have found, when choosing your whey protein powder, the structure and digestibility of the whey protein remain the same whether it’s from A1 or A2 cow’s milk. So, while A2 milk may appeal to those seeking a more digestible dairy option, the quality of whey protein should be evaluated based on its purity, sourcing, and processing over the type of milk it’s derived from.

When choosing the best quality whey protein powder, we’d recommend looking beyond A1 and A2 distinctions. Whey protein concentrate contains very little lactose, and whey protein isolates even less, so they are often suitable for those who suffer from lactose sensitivities.

For those unable to tolerate casein protein, the other major milk allergen, whey protein powder is normally free from anything more than trace levels. This means whey protein powder is generally well tolerated among people who might ordinarily have a negative reaction to dairy products. Whey protein is a much less common allergen than either lactose or casein.

Some of the quality markers you can keep an eye out for in your whey protein include:

• Organic sourcing: Organic whey protein comes from dairy cows which aren’t exposed to pesticides, routine antibiotics, or growth hormones, ensuring a cleaner protein source.
• Grass-fed cows: Organic, grass-fed cows are also raised on natural pastures as far as the weather allows. This means the milk they produce – and the whey derived from it – contains more beneficial nutrients like omega-3 fatty acids and CLA (conjugated linoleic acid). (10) CLA is a fatty acid found in meat and dairy, thought to offer various health benefits. (11)
• Gentle filtering: Choosing a whey protein that’s ‘cold-pressed’ and free from artificial ingredients or unnecessary additives supports your health without exposing your body to additives or fillers.

While the A1/A2 distinction is potentially important when it comes to casein protein, it doesn’t impact whey protein. Whether sourced from A1 or A2 cows, whey protein remains structurally the same and equally effective in supporting your nutritional goals.

When choosing a whey protein powder to complement a balanced, whole foods diet and increase your protein intake, it’s more important to focus on quality, sourcing, even taste and texture. This will ensure you enjoy using it and enjoy all the benefits a high-quality whey protein powder can provide.