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The Story on A2 Milk

You may have seen A2 milk in the store and wondered what the story is on this milk option. Here’s some info to help you better understand this product.

Approximately 82% of the protein in cow’s milk is casein. Beta-casein is the second most common of these casein proteins. There are 12 variants of the beta-casein protein gene; A1 and A2 are the most common. The difference between A1 and A2 is due to one amino acid. In A1 the amino acid histidine is in position 67 of the chain, but in A2 the amino acid proline is in that position. This seems to affect how the protein is digested.

Regular cows milk in the US contains a mix of both A1 and A2 proteins with standard US dairy cow’s milk containing close to equal amounts of the A1 and A2 forms of beta-casein. Cows in a good part of Asia and Africa and parts of Southern Europe naturally produce only A2 proteins.

Originally, all cows produced milk with only A2 but a single gene mutation in Holstein cows thousands of years ago resulted in a genetic change which spread as Holsteins were cross bred.

For some people consuming dairy products results in digestive issues. Their milk intolerance may be due to an inability to break down the milk sugar lactose. In others, milk intolerance may instead be the result of protein intolerance, specifically to the A1 beta-casein protein.

The study results on A1 are controversial, limited and conflicted in some expert’s opinions but have suggested A1 beta casein could contribute to a variety of disorders including heart disease and diabetes. It is important to point out that these studies showed only correlations and did not prove cause.

A2 beta-casein only cow’s milk has been on the market in Australia and New Zealand for a number of years. The a2 Milk Company is now distributing A2 only milk in China, Western Europe and parts of the US.

If you don’t tolerate milk, would like to consume it, and don’t have a milk allergy you might give A2 milk a try. A2 milk is not lactose free and contains as much lactose as A1 milk so it won’t help you if you are lactose intolerant. You can check the a2 milk company website for availability in your area. Sprouts and Whole Foods carry it. As you might expect A2 milk is more expensive than regular milk.

Keep in mind that with planning and good food choices you don’t have to drink milk to meet your daily calcium requirements. However, if you want to drink milk in moderation, but don’t tolerate it, there are options worth trying that might help you consume a food you want to enjoy.


posted on 1/18/2018