A2 Milk

A2 milk is cow's milk that contains predominantly the A2 type of beta-casein protein rather than the more common A1 protein commonly found in regular milk. Milk with predominantly A2 protein is licensed and marketed by the a2 Milk Company and sold mostly in Australia, New Zealand, China, United States and the United Kingdom. "a2 milk" and "A2 MILK" are trademarks but the phrase "A2 milk" is widely used to discuss milk with predominantly A2 protein.

The company marketing milk with predominantly A2 protein claims that milk containing A1 proteins are harmful, but a 2009 European Food Safety Authority (EFSA) review of scientific literature found there was insufficient evidence to prove that bioactive peptides in A1 milk have a negative effect on health.

A1 and A2 beta-casein are genetic variants of the beta-casein milk protein that differ by one amino acid. The A1 beta-casein type is the most common type found in cow's milk in Europe (excluding France), the USA, Australia and New Zealand. A genetic test, developed by the A2 Milk Company, determines whether a cow produces the A2 or A1 type protein in its milk. The test allows the company to license milk producers once proven their cows produce predominantly A2 beta-casein protein in their milk, to the exclusion of the A1 beta-casein protein type.

The European Food Safety Authority (EFSA) reviewed the scientific literature and published a review in 2009. As part of their evaluation, the EFSA looked at the laboratory studies that have been done on BCM-7. They found that experiments in cells and animals have shown that BCM-7 can act as a weak opioid receptor agonist, but that in most of the animal studies, BCM-7 was not administered orally, as humans would be exposed to it, but rather was given to animals by injection into the peritoneal cavity or even directly into the spinal cord or brain, which makes these studies not useful for understanding how BCM-7 might affect humans. The EFSA found no relationship between chronic diseases and drinking milk with the A1 protein. The EFSA study emphasized the dangers of drawing conclusions from correlations identified in epidemiological studies and the dangers of not reviewing all the evidence at hand. Another 2009 review found no demonstration that consuming milk with A1 casein causes diabetes. A 2014 review of research into the relationship between consumption of dairy products (including A1 and A2 proteins) and the incidence of diabetes found that while there appears to be a positive correlation between consumption of dairy products by babies and the incidence of type 1 diabetes (T1D) in some people, and an inverse relationship between the consumption of dairy products and the development of type 2 diabetes (T2D) in some people, these correlations are tentative, it is impossible to determine what component or components of milk might be responsible for these effects, and it is unlikely that the expensive and complex research to determine the answers to these questions will ever be conducted.

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