If you find that milk doesn’t agree with you like it should, it may not be the lactose in the milk.  In fact, it might be a type of protein called A1 beta casein.  Find out exactly what the different types of beta casein are and how they can affect you. 

What is Beta Casein?

Beta casein is an important protein found in cow’s milk, and makes up about a third of the total protein content.  All cows make beta casein but it is the type of beta casein that matters.  There are two types – A1 and A2.  A1 and A2 beta caseins differ by only one amino acid.  A1 beta casein produces an opioid-like reaction in the body.  A2 beta casein has been shown to be the original beta casein that was produced by the first domesticated cows.

Most farmed cows now produce the A1 beta casein.  These include Holsteins and Friesians (which produce A1 and A2 in roughly equal proportions).  A2 beta casein is produced by ancient breeds of cattle such as Zebu cattle, as well as buffalo, goat, yak, and sheep.  The Guernsey cow produces milk that contains around 90 percent of A2 beta casein, while Jersey cows produce moderately more A2 beta casein in their milk than regular farmed cows.

What is A2 Milk?

A2 milk is milk that is naturally higher in levels of the A2 beta casein protein.  This milk is thought of as being healthier than milk that contains A1 beta casein due to the bioactive peptides that it releases when digested.  As well as its health benefits, A2 milk is nutritious.  It is not genetically modified and does not contain any additives.  A2 milk contains the same amounts of calcium, other minerals, and lactose as normal milk.

Risks with A1 Beta Casein

A1 beta casein has been linked to type 1 diabetes.  People with type 1 diabetes have higher levels of antibodies to non-diabetics, and they are specifically antibodies to A1 beta casein.  Evidence has also shown that a high intake of regular milk is a strong risk factor for diabetes.  A1 beta casein has also been linked to heart disease. It has been suggested that it can cause arterial plaque to develop and can oxidise LDL cholesterol (bad cholesterol).  Regular milk may also be associated with autism, as many autistic people have intestinal problems and increased gut permeability (allowing substances such as A1 beta casein to cross more easily into the blood).

Why Drink A2 Milk?

You should note that A2 milk and regular milk both contain the substances that cause milk allergies.  A2 milk simply does not have the A1 beta casein, which is linked to other diseases.  A2 milk has the same levels of lactose as regular milk, so drinking A2 milk cannot solve a lactose intolerance or allergy problem.  It is interesting to note that a factor in regular milk, BCM7, is released when A1 beta casein is digested.  BCM7 is a strong opioid that can affect gut processes and mucus production – causing some allergic or intolerance symptoms.  BCM7 can also stimulate skin reactions and the release of histamine.    A2 milk does not produce BCM7 on digestion. 

If you do have an allergy to milk, you should talk to a medical professional before trying A2 milk.  If you are allergic to the proteins in standard cow’s milk, you cannot drink A2 milk.