What is A2/A2 milk?

In order to understand why consuming A2/A2 milk is a much healthier option for us, we must first understand a bit of the science involved. So, are you ready for a little biochemistry?

Milk from dairy cows contains approximately 85% water, with the remaining 15% comprised of lactose, fat, minerals and protein.  Of the protein content, casein proteins make up 80%, and whey makes up the remaining 20%.  Casein proteins can further be classified into 3 types: alpha, beta and kappa.  

When we speak about A1 and A2 milk, we are speaking of the beta casein protein, which has been the focus of study over the last few years. A2 beta casein protein has been produced by cattle for many thousands of years.  I found it very interesting to learn that human breast milk is of the A2 beta casein type.  (This fact alone, would indicate to me that we were not meant to be consuming the A1 protein.)  At some time around the year 1000 AD, it is believed that a natural mutation occurred in some of the European dairy breeds that altered the A2 protein and introduced the A1 variant.  Today, our popular high producing Holstein cattle of European ancestry are the major carriers of the A1 variant.  Other less common breeds such as the Jersey and Guernsey carry the A2 protein more of the time.  

Let's talk basic genetics.  Cattle today can be heterozygous (A1/A2) meaning they will produce both types of beta casein protein in their milk.  They may also be homozygous (A1/A1  OR  A2/A2).  A cow that is A1/A1 will never produce the A2 protein and similarly, a cow that is A2/A2 will never produce the A1 protein.

The cows at Stoney Hill have been tested A2/A2 and will never produce the A1 protein

Why is A2/A2 milk important?

Proteins are made up of amino acids that are linked together in a chain.  The beta casein protein is 209 amino acids long.  When the mutation occurred, the amino acid in the 67th spot in the chain was switched from proline (in the A2 protein) to histidine (in the A1 protein).  When histidine is present in this location, the enzyme responsible for digestion locates the histidine and cleaves apart a stand of 7 amino acids known as betacasomorphin-7, or BCM-7.

This short chain peptide known as BCM-7 is an exogenous opioid, which means that it does not naturally occur within the body.  Opioids are known to cause mental confusion, nausea, constipation and respiratory depression which makes sense, since we have opioid receptors located within our brain, spinal cord and gastrointestinal tract.  The BCM-7 peptide is capable of interacting at all of these sites. 

Because illnesses can have a wide array of contributing factors, direct causal relationships are difficult to prove.  However, research has linked the BCM-7 peptide to type 1 diabetes, heart disease, autism, and other non-communicable diseases.  Please see below for links to scientific research papers.

Rachel's raw milk theory

I have found it interesting that people with eczema and digestive problems have sought after raw milk based on personal testimonies alone that state drinking raw milk has alleviated these conditions.  While I have no opinion about drinking raw milk, I have found myself considering the following…

Few, if any of the small raw milk producers I have encountered are raising Holsteins, but rather Jerseys or Guernseys.  This fact alone begs me to ask:

"What if it is not simply the raw milk that relieves these people of eczema and digestive complications, but rather the fact that these people are consuming milk from cows producing A2 beta casein?"

Consider for yourself

For those of you who do not accept everything at face value, you may choose to do some research of your own.  As you begin your inquiry about A2 milk, you will find as I did, that much of the research is funded through the Australian based A2 Milk Company does seem a bit coincidental at first glance.

The irony, is that for a few years now, the domestic US companies that supply frozen semen for breeding cows have been testing bulls for the A2 protein.  This information is readily available along with the bull proof or genomics numbers (information that indicates to the farmer what the bull's offspring will look like or how much milk they will produce).  Because it is possible to breed A2 protein genetics into cows, it is my opinion that the bull stud companies would not be going through the hassle of testing their bulls if the A2 protein was of no importance to future markets in the dairy industry.

Having also been part of the dairy industry in Wisconsin for over 2 decades, I also know that the Milk Marketing Board and other National Milk Checkoff Programs (these are mandatory payments that get deducted from a dairy farmer's paycheck to promote dairy products, whether or not the farmer wants to contribute) are massive in scale and political power.  I believe that milk processors will do all they can to gain a marketing advantage for fluid milk. Soon, you will find milk labelled A2 that is produced by cows on factory farms (CAFO’s ) that have never been tested…they will assume to be A2 by breeding alone. What most people won’t know is that many of these farms run ‘clean up’ bulls to breed the cows that don’t get pregnant by artificial insemination. Those bulls are likely untested and could bring the A1 variant into the ‘A2’ milk you’ll find at the grocery store. The moral here? Know your farmer and you’ll know your milk (or eggs, or meat!)

At Stoney Hill, we would love the opportunity to provide a local group of people access to our A2 milk. Unfortunately, dairy regulations in Wisconsin make this a challenging and costly effort for small producers.

Resources

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586534/  (This article discusses in depth the BCM-7  peptide and discusses milk intolerance and other effects)

http://www.betacasein.net   (This website will give you access to much of the published studies on the effects of the BCM-7 peptide.)

Book: Devil in the Milk  by Keith Woodward   (This book is an interesting overview of the biochemistry and politics involved in A2 milk.)