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Difficulties with – Is A2 the Answer?

So often, when someone experiences stomach pain, bloating, diarrhea and/or other disturbing gastrointestinal discomfort after milk or dairy products, he or she assumes “I guess I’m lactose intolerant and can’t enjoy milk anymore” – and that could be true, as an estimated 30-50 million Americans lack the ability to digest and absorb the naturally occurring milk sugar, lactose. However, some emerging research suggests that these unfortunate individuals may not have a , but rather a intolerance. It is thought that A1, a natural variant of cow’s milk beta- protein may be culprit behind these less-than-pleasant post-dairy experiences, and that the relatively new-on-the-market “” may offer some relief to those that have difficulties with dairy.

Milk Protein 101: There are 2 major protein groups in milk – casein and , the majority of which is casein. are actually a group of ; about 1/3 of caseins are beta caseins. The beta caseins have 2 common variants, A1 and A2 beta casein. Most milk contains a mixture of the A1 and A2 beta casein (about 60% A2, 40% A1), however, the ratio of these A2 and A1 proteins can vary with different breeds of dairy .

The Background: Thousands of years ago, cows only made milk with the A2 beta casein protein (not the A1). Some 8,000 years ago, a natural single genetic mutation of the beta casein protein gene in Holstein cows (the stereotypical black and white dairy cattle) resulted in production of milk with the A1 (and A2) beta casein protein. As Holsteins were bred with other breeds, the mutation spread, resulting in 12 genetic variations of the beta casein protein; of those, A2 and A1 are most common.

A1 and A2 Beta Casein Proteins – What’s the difference? A1 and A2 beta casein proteins differ by only a single , however, they are digested differently. The breakdown of A1 beta casein protein (not A2) during digestion in small intestine produces a called beta--1 (BCM-7). The intestines absorb BCM-7 and it is then passed on into the blood stream.

There are several studies that suggest that BCM-7 (which is a byproduct of A1 beta casein digestion, but not A2) has inflammatory properties that can cause gastrointestinal symptoms similar to those of lactose intolerance – abdominal pain, gas, bloating, diarrhea, etc. In at least one study done on people that have self-reported problems with dairy, those that consumed milk that only contained the A2 variant of beta casein protein (and therefore were not exposed to BCM-7) reported less discomfort afterwards.

What’s A2 Milk? A2 beta casein cow’s milk is milk that comes from cows that are hand-selected (genetically tested) to only produce milk with only the A2 beta-casein variant; the cows do not have the gene to produce milk with A1 beta casein. A2 milk has been available in Australia and New Zealand since the early 2000’s and is available in the US now. Some American dairy farms are converting their herds to A2-producing milk, in anticipation of continued interest in this “new” milk in the U.S. In San Antonio, at the time of the writing of this article, you can find A2 beta casein milk at Sprouts and Whole marketed by .

Like Drinking Milk But Don’t Feel So Good Later? If you don’t have a true, diagnosed milk (these can be life-threatening), and aren’t REALLY sure if you are lactose-intolerant or not, but know that you don’t feel good after consuming milk/dairy products (stomach pain, bloating, gas, diarrhea, nausea, etc.), you may want to try a lactose-free milk to see if it helps (Lactaid, Mootopia, HEB Lactose-Free milk). If you feel okay after drinking lactose-free milk, voila! You’ve found the culprit to your woes – lactose! If you continue to experience symptoms after lactose-free milk, you may want to give A2 milk a try. If you can enjoy A2 milk without any problems, you can deduce that you probably have an intolerance or sensitivity to A1 beta casein protein. Both lactose-free milk and A2 milk contain all the protein, vitamins, and minerals as “regular” milk, because they are real milk.

Bottom-Line: Current science supports consumption of cow’s milk and dairy products as sources of essential nutrients. There isn’t strong evidence to prove that A2 milk is “healthier” than ordinary milk that contains A1 and A2 beta casein protein. There is limited evidence to suggest that A2 milk may help prevent digestive issues in some individuals that are experience unpleasant symptoms after consuming milk. A2 milk and ordinary milk (that contains A1 and A2 beta casein protein) are safe, wholesome, nutritious, and part of a healthy balanced diet. If you have more questions about dairy foods or any other nutrition-related matter, be sure to set up a nutrition assessment with Campus Recreation’s registered dietitian nutritionist, Annie Bell. Appointments are individualized to address your needs, questions, and concerns and last about an hour – oh, and they’re free! Follow the prompts here to register: https://campusrec.utsa.edu/nutritionregistration

https://www1.nichd.nih.gov/publications/pubs/documents/NICHD_MM_Lactose_FS_rev.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818854/ https://www.medicalnewstoday.com/articles/318577.php http://www.todaysdietitian.com/newarchives/1017p26.shtml http://cdrf.org/2017/02/09/a2-milk-facts/ https://www.a2milk.com