What Is a2 Milk? Your Questions About a2 Milk Answered

Part 1 of a two-part series on a2 milk. For part 2 click here.

A Doctor (& Registered Dietitian) Examines the Evidence.

The myths and facts about a2 milk – details to help you decide if you should give it a go!

What is a2 milk?

Traditional cow’s milk has been blamed for a variety of symptoms ranging from digestive discomfort to inflammation. Supporters of a2 milk, a fairly new player on the market, claim it doesn’t have these same negative effects. But you may be wondering – is this true? And you might have more questions. Is it genetically modified? Can you drink it if you are lactose intolerant? How much does it cost?  Let’s get to answering these questions and others.

Milk contains two main proteins; casein and whey (1). Casein is the major protein in milk and has two forms, a1 and a2. Most milk currently found in markets contains predominantly the a1 form of the protein. A2 milk contains only the a2 protein.  It is derived from cows that are specifically bred to produce only a2 milk.

Thousands of years ago, cows only produced the a2 type of protein in their milk. When cows were domesticated about 8,000 years ago, they started to produce a1 protein (2). Cows now must be specifically bred to produce only a2 protein milk.

Some research suggests we may be able to better tolerate milk that contains the a2 protein. This is the same kind of milk protein found in goat’s milk and sheep’s milk, and is known for being better tolerated than regular cow’s milk (3).

A2 milk was first sold in Australia and New Zealand and has expanded to the US and Europe. A2 has been available in the US since 2015 and is most widely available in California (4).

The nutrients in milk include protein, fat, and carbohydrates. Milk is hydrating – it is nearly 90% water. It is a good source of calcium, as most people know, but it is also a good source of vitamin B12, riboflavin, phosphorus, and selenium (5).

The protein in milk is a complete protein. This means that it provides all of the essential amino acids that we are unable to make ourselves (6).

You may be able to tolerate a2 milk if you have lactose intolerance.

Lactose is the main sugar in milk. Our ability to digest lactose depends on our genetic potential as well as our gut health. If we are eating foods that damage our gut, we eliminate the lactase enzyme (and our ability to digest lactose), too.

Both “regular” a1 milk and a2 milk contain the same amount of lactose. If you don’t tolerate regular milk because of the lactose, you might not tolerate a2 milk either (7). However, if you are experiencing discomfort after consuming milk, it is possible that you’re experiencing an inflammatory response to the protein, not the milk sugar lactose. Some research suggests that folks who believe that they have a lactose intolerance actually do tolerate a2 milk better (8). This is because symptoms attributed to lactose may be due to inflammation and not lactose in some people.

A2 milk is not safe if you have a dairy allergy.

If you have a dairy allergy, A2 milk is not safe for you. Do not drink A2 milk or consume any products made with a2 milk if you have a milk allergy.

A2 milk may be better tolerated if you have a sensitivity/intolerance to regular cow’s milk, cheese or other dairy products. It is NOT meant to be consumed if you have a dairy allergy.

If you have a dairy sensitivity, it may be worth experimenting with a2 milk or lower-casein options, such as goat’s milk or sheep’s milk products. You may be pleasantly surprised that you can tolerate it. If you do not, you may feel better sticking with dairy-free alternatives and skipping milk altogether.

Note: a2 milk powder contains soy lecithin (10).

No, a2 milk is not genetically modified.

Cows producing a2 milk undergo selective breeding. This means that cows who are producing the a2 milk protein are bred together to produce more cows that make the a2 protein (9).

Yes. A2 milk is available worldwide and in the U.S. at many large chain grocery stores. Several U.S.- based options to purchase a2 milk are listed below. For other locations in the US or world, a quick search on the internet may locate products near you.

A2 cheese also exists as does a2 yogurt. More options for a2 milk products will be made available by the producers of a2 milk if consumer demand continues to increase. A2 ice-cream, cottage cheese, sour cream, and kefir may not be far off (11).

1. A2 Milk Company– On their site is a product locator. Their products are carried at Walmart, Target, Whole Foods, Lucky, Safeway and other chain markets
2. Bunker Hill– Online ordering
3. Azure Standard– A monthly food delivery cooperative service. Deliveries are across the U.S.
4. Millers Biodiversity Farm– A store or delivery locator is on their website

Yes- organic a2 milk is available.

The regulations around using the organic credential are based on how the cows are raised and what they eat. In order to have certified 100% organic milk, cows must eat 100% organic feed. If an a2 cow is fed organic feed, she will produce organic a2 milk (“12). Alexandre Family Farms makes delicious organic a2 milk products.

Yes, grass-fed a2 milk does exist, but it is harder to find currently (13).

Similar to the regulations around organic, a cow that is certified as grass-fed is allowed to only eat grasses and legumes, not grains (14).

The potential health benefit here is in the fatty acid profile of the milk she produces. Grass-fed cows produce milk that is higher in omega-3 fatty acids, lower in omega-6 fatty acids and higher in vitamin E (15). If you choose to prioritize grass-fed while grocery shopping, reach for the whole milk to maximize these benefits.

Cow’s milk allergy is the most common allergy in childhood and its prevalence is on the rise. The World Health Organization recommends exclusively breastfeeding infants until six months of age, but that is not feasible nor the goal for all mothers (16).

Introducing hydrolyzed dairy may lower the risk of developing a cow’s milk protein allergy. If your child is not tolerating a standard cow’s milk formula, an a2 milk formula is one alternative that you can try (17).

Always speak with your child’s pediatrician if you have questions about the best choices for feeding your child.

Yes – it costs about twice as much.

Non-organic a2 milk is about the same price as organic “regular” milk. The exact difference in pricing will depend on your local grocery store. 

If you already include dairy in your diet and will continue to do so, it might be worth a try.

The research is limited, but some studies suggest that a2 milk may have a lower risk of causing inflammation, cause less discomfort and have a lower the risk of having loose stool when compared to regular milk. (19, 20).

For some, dairy is inflammatory, no matter what kind it is or how it is processed. For others, there are moral or ethical reasons that guide them in their dietary decisions. The choice of whether or not to consume dairy of any form is a personal and health decision for each individual.

What you eat and drink is a powerful mediator of your health. You deserve to feel good!

*This information is not a substitute for medical advice. Please consult your health care provider for questions specific to your needs.

THIS ARTICLE IS COPYRIGHTED BY AMY BURKHART, MD, RD.