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Understanding the A2 versus A1 Beta-Casein Comparison

posted on

February 2, 2024


Many of you buy our dairy products, not just because it is raw and organic, but also because it comes from A2/A2 Jersey Cows. Most intelligent, health-conscious people will go out of their way to source A2/A2 dairy because they have heard of the health benefits.

But why?  

What are the health benefits? 

Ya’ll have been asking me to explain this in detail and do it in a way that can be easily understood. 

I will do my best, today, to explain why A2/A2 is optimal for your health.

Here we go!

Let’s begin with the chemistry. 

All species in the animal and plant kingdom are made up of proteins, carbohydrates, fats, minerals, and water.

Some species have a higher percentage of protein and are lower in carbohydrates, but every organism has some small amount of each macro-nutrient in its makeup.

Every mammal on the planet makes milk which also contains fats, carbs, and proteins. These milk proteins consist of two types:  1) Whey and 2) Casein.

Casein makes up around 80% of the protein in cow’s milk.

There are also Casein sub-types. One of these sub-types, called Beta-Casein, makes up about 30% of the protein in cow’s milk.

Most every species of mammal on the planet has ONLY the A2 Beta-Casein genetic factor.

Except COWS!!!

Cows can have THREE forms of Beta-Casein: A1, A2, and a combo A1/A2.

This is very strange.

Why is it that ONLY domesticated cattle of all the mammals on the planet have more than one Casein genetic factor?

On average, more than 70 percent of the older heritage breeds like Jersey and Guernsey cows produce milk with predominantly A2 protein. While among the more modern breeds of Holsteins and Ayrshires, between 46 and 70 percent produce milk containing A1 only or the A1/A2 combination.

We don’t know exactly how or when this mutation happened. Perhaps cattle evolved to have this genetic shift from a change in their habitat. Or, perhaps, human intervention contributed to the shift from grass to grain feeding, mass production, and growth-hormones.

Most milk you find in the stores in Europe, the United States, and the UK is A1 or A1/A2.

What We Do Know: 

  • A1 milk is a relatively new thing found in the industrialized world.
  • A1 adult cows give this A1 gene to their offspring and A2 cows give this A2 gene to their offspring.
  • You can test the Beta-Casein in cows and determine if it is A1, A2, or A1/A2.
  • You can selectively breed for one of these three combinations.
  • The molecular structure of A2 milk more closely resembles that of most all other mammals on the planet including human breast milk, which could have implications on how it’s processed by the human body.

A2 and Your Health 

Studies began in New Zealand in the 1980s which found correlations between the prevalence of milk with A1 beta-casein proteins in some countries and the prevalence of various chronic diseases.

A2 researchers found that A1 Beta-Casein causes the production of an opioid peptide called beta-casomorphine-7, or BCM-7, which causes inflammation in the gut of animals and humans.

And, we all know that inflammation can contribute to a long list of diseases.

BCM-7 can also cause digestive issues.

In fact, some researchers believe that BCM-7, not lactose, is the culprit behind many people’s trouble digesting cow’s milk.

Furthermore, an amino acid in A2 milk called Proline may actually PREVENT the production of BCM-7, which can make it easier for some people to digest and less likely to cause inflammation in the body.

The sole difference is that one of the 209 amino acids that make up the beta-casein proteins, a proline occurs at position 67 in the chain of amino acids that make up the A2 beta-casein, while in A1 beta-casein, a histidine occurs at that position. Studies in cells found that digestive enzymes that cut up proteins interact with beta-casein precisely at that location, so that A1 and A2 beta-casein proteins are processed differently. A seven-amino acid peptide, beta-casomorphin-7, can be cut away from the A1-beta-casein protein by those enzymes, but the enzymes cannot cut the A2 protein at that location, so BCM-7 is not formed from A2 proteins.

The A1 beta-casein protein breaks down into a peptide called BCM-7. As stated in an article in the Indian Journal of Endocrinology and Metabolism, “BCM-7 is suggested to be associated as a risk factor for human health hazards as it can potentially affect numerous opioid receptors in the nervous, endocrine and immune system.”

The list of chronic health issues related to BCM-7 is very long and varied. It includes type-1 diabetes, heart disease, SIDS, autism, schizophrenia, and gastrointestinal problems.

A recent study in China compared the effects of A1 and A2 milk on both clinical status and various biomarkers in 45 people with just such dairy intolerance. There was a significant reduction in both intestinal function, stomach discomfort, looser stools, and inflammatory markers with the ingestion of A2 milk. Surprisingly, these benefits were seen in both lactose tolerant and lactose intolerant participants--suggesting that some of the symptoms routinely attributed to lactose intolerance may actually relate to BCM-7. Though small, this study was of high quality, both randomized and double-blinded.

Health Challenges of A1 Dairy


Researchers looked at markers of inflammation in the blood. They found the participants had higher levels of inflammatory markers after they drank A1 milk.

Brain function 

Research showed that milk could impact brain function. Study participants took longer to process information and made more errors on a test after drinking regular milk compared to A2 milk. 

Type 1 Diabetes

Early exposure to milk in susceptible individuals is suspected as one of the potential causes of type 1 diabetes, and inflammation is part of that pathway. There is published research that this may be induced preferentially, or even exclusively, by the A1 variant.  

Some animal studies show associations between cow’s milk consumption and a higher incidence of type 1 diabetes. One study in mice found that 47 percent of the mice that had A1 protein added to their diet developed diabetes, while none that had A2 protein added did so.  

Heart disease  

A study in rabbits looked at the effect of A1 and A2 proteins on cholesterol levels. Rabbits fed the A1 protein developed an increase in their cholesterol levels. A rise in blood cholesterol is indicative of a healing response due to an irritant, likely A1 Beta-Casein, entering the circulatory system. The body produces cholesterol to repair the irritated arteries.

Some research conclude that cholesterol is not the problem, rather the cure. While consuming A1 protein is associated with a higher risk for heart disease along with stress, smoking, sugar, lack of exercise, etc.  

What has been the Commercial Dairy Industry’s Response?

Of course, there has been push back by the A1 milk industry to discredit and disprove this as the A1 dairy industry rules as King.

And, just like assuring us that GMOs are safe, antibiotics are safe, chemical fertilizers are safe, steroids are safe and vaccines are safe, they will likely not make a stand for the health risks of A1 milk either.

Publication of the book, Devil in the Milk, by Keith Woodford, about A1 beta-casein and its dangers to health, boosted awareness of A2 milk in Australia, New Zealand, and ultimately in the US.  

How Do We Measure Up?     

  • Our Dairy Products are 100% Raw.
  • Our Cows eat 100% Grass.
  • Our Grass is NEVER sprayed with Glyphosates, Herbicides, or Pesticides.
  • Our Cows live Outdoors with Sunshine, Fresh Air, Fresh Water, and Exercise.
  • Our Cows NEVER eat Grains.
  • Our Cows NEVER eat GMOs
  • Our Cows NEVER eat SOY
  • Our Cows NEVER receive Antibiotics.
  • Our Cows NEVER receive growth hormones.
  • Our Cows NEVER receive Vaccines.
  • Our Cows are ALL 100% A2/A2 Beta-Casein tested Jersey cows.
  • We only use Organic Animal Rennet in our cheese making.

Check out Cornucopia Institute to learn how we at Alpine Heritage Creamery compare to the rest of the herd.

We are proud of our 5-star rating and would do nothing less to help make America healthy and strong.

I hope this helps.  

Don’t hesitate to contact us if you have any questions.

Click here to purchase our Organic Raw A2/A2 Cheeses.

Phoenix and The Simply Grassfed Families


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 – Pub Med-NIH-National Library of Medicine

Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study

Milk Proteins and Human Health, Indian Journal of Endocrinology and Metabolism, published in PubMed and NIH -National Library for Medicine

A1 Beta-Casein pre-disposing factor in Type 1 Diabetes

Other Related Articles:  

Cheese is Our Culture

What is Raw Cheese and How is it Different from Pasteurized ?

What is Alpine Cheese Making and What Makes it Different?

Vitamin and Mineral Content is Greater in Grass Fed Cows Vs. Conventional

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