What is A2 Milk?

What is A2 Milk?  Is A2 Milk Better? Why is A2 Milk Better? A2 Milk Side Effects?  AGN Roots Grass-Fed Whey

Is A2 Milk Better?

Let's begin this discussion by building some perspective around the topic of milk production.

Did you know milk production worldwide now surpasses 532 million metric tons annually? Of that global production, the United States accounts for roughly 20% while Europe continues to dominate global supplies producing a whopping 30% [1]. In terms of the world leaders in production, here are the top 5 for 2020.

2020 Cow Milking Producing Countries Million Metric Tons
Europe (EU-28) 157.5
United States 101.1
India 93.8
China 33.0
Russia 31.65

Given the abundance of milk produced globally, it's not surprising to think of all milk not being equivalent. We know this to be accurate; some milk is better than others.

Consider that in the United States, over 96% of the milk produced is from factory farming operations. If being healthy and providing your family with the highest quality nutrition is the desired outcome, then sourcing, composition, and accreditation are priorities.

Although the beta-casein protein type has gained notoriety in the last decade, much more significant benefits to our digestion and nutrition reside within the sourcing efforts. Demanding a grass-fed accreditation to avoid the factory farm models taking over the west will have incredible quality benefits to your milk.

Most of our articles focus on sourcing as the origins of dairy in this day and age seem to have the most significant impact on quality; this article, however, dials in another topic, milk protein composition, with emphasis on the bovine breed. Do the science and the marketing of A2 Milk agree?

In this A2 Milk Explained guide, we'll review everything you need to know about A2 milk and provide the facts & fiction when it comes to answering these questions

  • What is A2 milk?
  • How is A2 Milk made?
  • Is A2 milk better than A1 milk?
  • What are the benefits of A2 milk?

Learn More: Heavy Metals in Factory Farms
Learn More: The Destruction of Milk Quality

The Composition of Milk

To answer the question "what is A2 milk," it helps to have a basic understanding of milk and it's protein composition.

There are two major proteins available in cow's milk. About 80% is casein while 20% is whey protein [Milk Infographic]. Both contain their own list of nutritional benefits[2]. On this site for obvious reasons we focus on whey protein which the general breakdown (whey protein fractions) that looks like the following -

  • α-Lactalbumin
  • β-lactoglobulin
  • Serum albumin
  • Immunoglobulins
  • Other Proteins (ex. Lactoferrin)

Learn More: Lactoferrin Explained

There are four types of casein differentiated by the number phosphate groups per mole of casein. These four casein types include:

  • Alpha - s1 Casein
  • Beta Casein (includes γ-casein)
  • Alpha - s2 Casein
  • Kappa Casein

In terms of abundance in bovine milk, α-s1 casein is the most prevalent while beta-casein comes in second.

Beta-casein exists in two main variants: A1 and A2 beta-casein. Which brings this article into focus with the question -

Is A2 Milk a Myth?

Yes and No -

No, A2 Milk is not a myth. It does exist, and its composition is "as-advertised" as milk that contains the A2 type of Beta-Casein protein primarily. A2 Milk may provide relief for some people; this is also true.

Yes, A2 milk may hinder efficient digestion and introduce other issues; there is strong scientific consensus that A2 Milk is not a digestive sensitivity panacea that allows individuals who otherwise have problems digesting milk the perfect solution. Indeed, the self-citing scientific studies paired with marketing claims made by A2 Milk enthusiasts are beyond hyperbole.

Here are a few facts to keep in mind:

  1. A2 Milk® is a registered word mark with the USPTO from a company called "The a2 Milk Company Limited" [11].
  2. Regardless of the milk's origin, only brands that have in place a trademark licensing agreement with the "The a2 Milk Company Limited" can place claim to branding their milk "A2 milk®". Although the word mark descriptor serves as an identifier, it offers very little value to individuals who have not pinpointed the specific source of their discomfort experienced with dairy consumption.
  3. When wrapped up into an overarching conclusion, all the scientific evidence overwhelmingly points to the digestive system. The person consuming the milk (their digestive tract) is the most significant factor in the sensitivity equation.
  4. All people are different; some people have a better experience when the A2 to A1 beta-casein ratio is high, while others are at ease when it's low.

Learn More: Protein Fractions Defined

Whey Protein Fractions Within A Milk Composition Wheel - AGN Roots Grass-Fed Whey

A2 Beta-Casein Type Protein History

The A2-Milk Theory:

As the internet would have us all believe, over 8,000 years, a single genetic mutation impacted the protein composition within the infamous Holstein breed. As the Holstein became very popular for its' ability to outproduce other bovine breeds in terms of milk quantity, the breeding and cross-breeding of Holsteins became popular, allowing this mutation to flourish.

Learn More Here: Why did the Holstein Become So Popular?

The A2 Milk Facts:

If we shy away from the assumption that our ancestors were capable of mapping milk protein composition or genetic mutations as it relates to dairy cattle over 8,000 years ago, we can then cover the facts we know to be true today.

It is a fact that beta-casein protein composition seems to be highly dependent on the breed of animal from which the milk comes.

For example -

  • Over 50% of the Jersey breed cows produce A2 beta-casein milk. 
  • Over 90% of the Guernsey breed produces A2 milk.

Previously, people believed cows only produced the A2 beta-casein milk. Over time, however, it became evident that both A1 and A2 beta-caseins are present in just about all milk available on the market today.

    What is A2 Milk Exactly?

    "A2 Milk" is cow's milk that mostly contains the A2 type of beta-casein protein from intentionally breeding out the A1 beta-casein type protein.

    Does A2 Milk Contain A1 Beta-Casein Protein?

    Yes, "A2 Milk" is not the absence of A1 beta-casein but instead carries a more substantial ratio of A2 versus A1.

    Is A2 Milk More Yellow than Regular Milk? 

    A2 milk often gets marketed as having a rich golden look; however, there is zero chance of making an educated distinction between A1 and A2 milk by appearance alone.

    The reason why a dairy product like milk, cheese, or butter would have a more golden hue is solely due to the beta-carotene contained in the milk.

    Beta-carotene is a phytonutrient that passes through into the milk directly from the lactating cow's diet. The higher percentage of fresh grasses that make up the animal's diet, the greater the likelihood of the milk taking on deeper shades of cream.

    Learn More Here: Why is Grass-Fed Dairy Slightly Yellow?

    What Cows Produce A1 Milk?

    • Holstein-Friesian
    • Ayrshire
    • Red Cattle

    What Cows Produce A2 Milk?

    • Guernsey
    • Jersey Cattle

    A1 vs. A2 Milk

    The global A2 milk market was valued at $1,129.7 million in 2019 [3]. It's projected to reach $3,699.2 million by 2027. Why are people obsessing over A2 milk?

    It helps to understand how A1 and A2 milk differ.

    Beta-casein in cow's milk can be composed of both A2 and A1 beta-casein in varying concentrations depending on the animal. The only structural difference is recognized in the secondary structure of the protein.

    Learn More Here: Protein Structures Explained

    In the secondary structures of the Beta-Casein protein the 67th amino acid is the distinguishing factor. 

    • A1 beta-caseins have Histidine in position 67
    • A2 beta-caseins have Proline in position 67

    Why do People think A1 Milk is Bad?

    The answer is manipulation and marketing from Dairy corporations desperate to make A2 Milk a health trend. It is harder to produce sufficient evidence supporting the benefits of A2 Milk in humans than it is to support conjecture as to why A1 Milk may not be great for us.

    The scientific theory, goes something like this -

    Proline has a strong bond with a small protein called beta-casomorphin-7 (BMC-7). In A2 Milk, this bond between Proline and BMC-7 prevents the BMC-7 from being released into the bloodstream.

    Histidine has a much weaker bond with BMC-7 than Proline; when our digestive tracts come across this pairing, the fragile bond can fail, which then releases beta-casomorphin-7 into the blood. So why is that bad?

    Is Beta-Casomorphin-7 (BCM-7) Bad?

    When BCM-7 enters the blood, μ-opioid receptors become active throughout the gastrointestinal tract. Up until this point the science is fairly certain. The real debate continues to swirl in the dairy industry as to whether our stomach ache can be attributed to these active μ-opioid receptors and thus A1-beta casein protein.

    The issues is that the publication that connects this expression of BCM-7 in the digestive system to sensitivities in the gut is inherently flawed by a conflict of interest. Disclosures at the tail end of this publication state clearly that the source of funding for the study comes from the A2 Milk Company [10].

    Other under-sampled experiments commonly cited tend to be funded by parties with skin in the game and by all measures represent a massive conflict of interest. 100% of the independent studies all conclude the same thing, the need for more extensive research.

    To date, the only scientific consensus is that milk containing a small or large ratio of A1 beta-casein compared to A2 beta-casein protein can have undesirable gastrointestinal responses dependent solely on the user.

    Is A2 milk better than A1?

    A2 Milk is better than any milk that comparatively triggers or increases digestive sensitives. The same is true for A1 Milk. Therefore, A1 Milk and A2 Milk are the same for some and not for others.

    Studies conducted independently from the Australian and New Zealand Food regulators have concluded that after extensive examination, there is no convincing or even probable evidence that the A1 beta-casein of cow milk has any adverse effect in humans.

    Pairing this with the national regulators mentioned above that have previously stated there to be no connection between A1 or A2 Milk and diabetes or any other diseases creates a decent case to dismiss the hype. [13].

    The next portion of this article focusses more on the marketing claims and business motives behind A2 Milk.  When it comes to business, this entire topic is ingenious.  Explained at a high level in six steps - 

    Company "A" -

    1. Produces milk in NZ with native cows
    2. Recognizes differences in the protein composition 
    3. Exhausts every resource to build a scientific bed rock as to how the beta-casein difference can become a competitive advantage
    4. Fails at building science backed evidence that supports the advantages of the protein composition
    5. Course corrects and targets low hanging fruit in terms of conjecture and hypothesis as to why the rest of the Industry's milk protein composition is bad
    6. Sells million and millions of ultra high temp pasteurized milk and charges a premium

    What Is the Science Behind Marketing A2 Milk?

    Everything is possible and requires further evaluation is the summary of almost all the publications. If you google this topic, you are likely to find audacious articles that kick-off with a hypothesis followed by content based on the premise of a scientifically proven view via nothing but the reader's pragmatic inference.

    Is it possible that BCM-7 can affect opioid receptors in the nervous, immune, and endocrine systems[4]? 

    At AGN Roots, we don't need to pretend we are analytical chemists by trade, so we are able to answer this this question with confidence, "sure, it is possible."

    It's also possible that beta-casein, type A1 or A2 Milk can increase your risk of:

    • Type-1 diabetes
    • Coronary heart disease
    • Arteriosclerosis
    • Sudden infant death syndrome
    • Autism
    • Schizophrenia

    Some studies have indicated that milk in general might cause health issues like:

    • Loose stool
    • Bowel inflammation
    • Discomfort
    • Constipation

    We only have broad range of studies and animal trials to work from, though.  

    Is A2 Milk Lactose Free?

    It's important to understand that the nuances between milk branded as "A2 Milk" and others have nothing to do with the amount of lactose (milk sugar) in the product. This article focused on protein sensitivities, while lactose is a sugar (disaccharides).

    As we learn more about our bodies and our nutrition, we've begun to understand that our bodies can react to many factors. Our bodies can respond to the beta-casein composition or the lactose concentration, yielding the same symptoms. How can you tell if you are lactose intolerant?

    Learn More: Lactose Intolerance vs Dairy Allergy Quiz

    Lactose intolerance is widespread; most people are sensitive to lactose to a varying degree. Lactose intolerance is a condition where the body fails to produce the enzyme lactase.

    Lactase is the enzyme that breaks down lactose and a popular supplement to help people with probiotic issues. Common symptoms include gas, bloating, and diarrhea. You'll find the same amount of lactose in A1 and A2 milk. The milk components in each one could cause these digestive issues.

    Some studies even suggest that A1 beta-casein might increase inflammation within the digestive system[5]. Keep in mind; this study does not reference humans.

    More Details About BCM-7

    Scientists are still trying to learn more about how A1 milk and BCM-7 affect the body. The studies are only observational and inconclusive at best. There is also an obvious lack of a representative sample (humans) being studied; clinical studies remain a wish list item.

    BCM-7 Conjecture

    It's possible that drinking A1 milk during childhood could increase your risk of type 1 diabetes. This study was only observational, though. While it might increase your risk, the study doesn't prove that A1 causes type 1 diabetes[6].

    Another observational study indicates that A1 milk could increase your risk of heart disease. A1 beta-casein might promote fat buildup in injured blood vessels. This could lead to clogged blood vessels and heart disease[7].

    Scientists also theorize that peptides like BCM-7 could play a role in the development of autism. In one study, infants with high levels of BCM-7 were strongly associated with an impaired ability to plan.

    Again, many of these studies are inconclusive and therefore too weak for us to make solid conclusions.

    The Benefits of Milk 

    What are the benefits of drinking milk beta-casein aside?

    Milk is rich in protein, which is an essential building block for your blood, skin, and muscles. Drinking milk could also provide your body with:

    • Vitamin A
    • Vitamin D
    • Vitamin B12
    • Vitamin K2 (Grass-Fed Milk)
    • Calcium
    • Riboflavin
    • Potassium
    • Thiamin
    • Omega-3 fatty acids (Grass-Fed Milk)

    Omega-3 fatty acids can benefit your health by[8]:

    • Improving your eye health
    • Fighting depression and anxiety
    • Reducing symptoms of metabolic syndrome
    • Promoting brain health during pregnancy
    • Decreasing the risk of ADHD, autism, and cerebral palsy
    • Fighting inflammation (which is associated with cancer, heart disease, and other conditions)
    • Reducing the risk factors for heart disease (reducing blood pressure levels, triglycerides, plaque, blood clots, and inflammation)
    • Reducing symptoms of ADHD in children
    • Improving your skin health
    • Fighting autoimmune diseases
    • Improving mental disorders 
    • Fighting age-related mental decline and Alzheimer's
    • Helping to prevent cancer
    • Reducing asthma in children
    • Reducing fat in the liver
    • Improving bone and joint health
    • Alleviating menstrual pain
    • Improving sleep
    • Decreasing violent behavior 

    Here are a few benefits of drinking Milk you might want to consider.


    Have you noticed changes in your mood lately? Vitamin D could help you avoid mood disorders like seasonal affective disorder (SAD). Milk is rich in vitamin D.

    You might experience a reduction in your SAD or mood symptoms as a result. 

    Blood Pressure

    One of the benefits of drinking grass-fed milk is its ability to help your blood pressure.

    High blood pressure levels occur when your cholesterol and triglyceride levels rise. Consuming more omega-3 fatty acids could lower your cholesterol levels. Remember, A2 milk contains plenty of omega-3 fatty acids.

    Milk also contains potassium. Potassium might support healthy blood pressure, too!


    With COVID-19 still a threat, more people are looking for ways to improve their immune systems. You can improve your immunity by adding vitamin A to your diet. Vitamin A is found frequently in animal products, including milk.

    Consuming vitamin A on a regular basis can improve your immune system cells' response and regulation.

    Bone Health

    Most people associate milk with calcium, which helps the body grow and repair bones. Drinking milk could keep your bones from growing weak. You could prevent or treat osteoporosis by drinking milk regularly.

    Eye Health

    As we get older, our eye health can start to deteriorate. Vitamin A can support your eye health, too. It can help maintain your corneas and retinas. 

    Try to drink milk as part of your regular, balanced diet to prevent cataracts. Consuming vitamin A can help your vision remain sharp, which can help your daily life. 

    Digestive Health

    Remember, drinking milk if you're lactose intolerant could cause symptoms like discomfort, inflammation, and bloating. The BCM-7 found in A1 milk could affect your digestion and cause similar symptoms, too. 

    One study compared the results of people who drank milk with A1 and A2 proteins versus those who drank A2-only milk[9]. Participants drank 8 oz of milk twice a day over the span of two weeks. After drinking the A2 milk, they reported no change in their symptoms.

    Those who drank the regular milk reported worse stomach pain. They also reported more frequent and looser stools.

    Full Disclosure: An author of this publication cited is also an employee with the A2 Milk Company. Is the date good? We leave that up to you. 

    Learn More: Digestive Enzymes for Milk Explained 
    Learn More: Prebiotics Explained

    Side Effects of A1 Beta-Casein Milk

    It's important to remember that regardless of the milk's beta-casein designation, milk still contains lactose unless it states "Lactose-Free". If you're lactose intolerant or have a milk allergy, A2 milk will most likely no solve much.

    Besides fundamental concerns associated with general dairy allergies, it helps to know the truth in concise facts. Below is a summary table with more details below.

     Marketed Side Effects - A1 Milk Statistical Causation: Y/N
    Cancer No
    Heart Disease No
    Type Diabetes No
    Reduced Brain Function No
    Increased Inflammation [10] No
    Asthma No
    Obesity No
    Rheumatoid arthritis No
    Type 2 Diabetes No
    Neurodegenerative Disease No

    What is A2 Milk?: Your Guide to Milking Every Health Benefit

    To recap, what is A2 milk?

    It's milk that contains more A2 beta-casein protein and less A1 beta-casein protein. While there are many expertly marketed potential health benefits to drinking A2 milk, the research is so far inconclusive.

    [1] Shahbandeh, M. “Production of Cow Milk Worldwide: Major Producers 2020.Statista, 19 Jan. 2021, www.statista.com/statistics/268191/cow-milk-production-worldwide-top-producers/.
    [2] Pasin, Gonca, and Gonca Pasin. “A2 Milk Facts.” California Dairy Research Foundation, 9 Feb. 2017, cdrf.org/2017/02/09/a2-milk-facts/. 
    [3] Thorat, Bhavana, and Roshan Deshmukh. “A2 Milk Market Size, Share: Global Industry Analysis Report, 2020-2027.” Allied Market Research, Dec. 2020, www.alliedmarketresearch.com/a2-milk-market-A06359. 
    [4] Sodhi, Monika et al. “Milk proteins and human health: A1/A2 milk hypothesis.” Indian journal of endocrinology and metabolism vol. 16,5 (2012): 856. doi:10.4103/2230-8210.100685
    [5] Ul Haq, Mohammad Raies et al. “Comparative evaluation of cow β-casein variants (A1/A2) consumption on Th2-mediated inflammatory response in mouse gut.” European journal of nutrition vol. 53,4 (2014): 1039-49. doi:10.1007/s00394-013-0606-7
    [6] Elliott, R B et al. “Type I (insulin-dependent) diabetes mellitus and cow milk: casein variant consumption.” Diabetologia vol. 42,3 (1999): 292-6. doi:10.1007/s001250051153
    [7] Laugesen, Murray, and Robert Elliott. “Ischaemic heart disease, Type 1 diabetes, and cow milk A1 beta-casein.” The New Zealand medical journal vol. 116,1168 U295. 24 Jan. 2003 
    [8] Hjalmarsdottir, Freydis. “17 Science-Based Benefits of Omega-3 Fatty Acids.” Www.healthline.com, 15 Oct. 2018, www.healthline.com/nutrition/17-health-benefits-of-omega-3. 
    [9] Jianqin, Sun et al. “Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows' milk.” Nutrition journal vol. 15 35. 2 Apr. 2016, doi:10.1186/s12937-016-0147-z
    [10] Pal, Sebely et al. “Milk Intolerance, Beta-Casein and Lactose.” Nutrients vol. 7,9 7285-97. 31 Aug. 2015, doi:10.3390/nu7095339
    [11] United States, USPTO. “United States Patent and Trademark Office.” Trademark Electronic Search System (TESS), USPTO - A2 Milk Registered Word Mark, 21 Oct. 2011, tmsearch.uspto.gov/bin/showfield?f=doc&state=4807:m2hn7i.2.13. (REGISTRANT) A2 Corporation Limited LIMITED LIABILITY COMPANY NEW ZEALAND.
    [12] Ho, S, et al. “Comparative Effects of A1 versus A2 Beta-Casein on Gastrointestinal Measures: a Blinded Randomised Cross-over Pilot Study.” Nature News, Nature Publishing Group, 2 July 2014, www.nature.com/articles/ejcn2014127.  
     [13] Truswell, A S. “The A2 milk case: a critical review.” European journal of clinical nutrition vol. 59,5 (2005): 623-31. doi:10.1038/sj.ejcn.1602104 
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    Thank you for your valuable information About a2 milk. This will help us.


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