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May 2024 Newsletter

Casein in Milk

Hello, this is Dr. Ellen. In this month’s ‘Real Common Sense’ newsletter, I want to look at an issue that concerns conventional cow’s milk and the dairy products made from it. Most people are familiar with a common problem with dairy products, namely lactose intolerance. This is usually caused by a lack of the digestive enzyme lactase in the small intestine causing impaired digestion of milk sugar. This can cause a number of gastrointestinal complaints. However, most people are not familiar with a particular dairy protein also found in many cow’s milk products that may lead to more serious detrimental health effects. It is A1 β-casein, found in conventional cow’s milk, which is sometimes referred to as A1 milk. However, this topic is somewhat controversial. Let’s take a look at it.

By the way, if you haven’t had a chance to see my previous newsletters, you can find them on my website, www.drellencutler.com under ‘Media’.

What is Casein and what is the Concern?

Casein is the major protein in milk, and β-Casein makes up about 30% of the total protein found in cow’s milk. The 2 major subvariants of this protein in cow’s milk are the A1 and A2 types, which differ by a single amino acid. Most commercially available milk contains exclusively A1 or a mixture of A1 and A2 β-casein unless the milk is produced by cows that genetically contain only the gene for A2 milk. The concern over cow’s milk containing the β-Casein A1 subtype is that digestion breaks it down into bovine casomorphin-7 (BCM-7). BCM-7 interacts with opioid receptors found throughout the body. The concern is that numerous studies have discovered that BCM-7 can cause a number of adverse health effects.(1)

It is interesting to note that other mammals, including goats, sheep, buffalo, and humans, produce only A2 milk.(2)

Potential problems with A1 β-casein

Several studies have demonstrated the role that A1 subvariant β-casein protein plays in promoting inflammation and its resulting effect on various aspects of health. Because of it, the gastrointestinal tract may develop an altered microbiota, increased production of mucus, and lactose intolerance-like symptoms. In fact, some studies have specifically shown that drinking A2 milk causes fewer lactose intolerance-like symptoms than drinking conventional milk.(1)  A study from China found that replacing conventional milk with milk containing only A2 β-casein not only reduced gastrointestinal symptoms in preschool children but also saw a corresponding improvement in cognitive performance.(3)

Other studies have shown possible problems of even greater concern. There may be a relationship between A1 milk and the development of type 1 diabetes as well as certain behavioral and psychiatric illnesses such as autism spectrum disorder (ASD), schizophrenia, and postpartum depression. Several studies have also suggested a correlation between A1 β-casein consumption and cardiovascular problems, but the results remain inconclusive.(1,4)  Yet another study suggested that eliminating the A1 type of β-casein from milk has the potential to increase the production of the body’s most ubiquitous antioxidant, glutathione.(5)

On the other hand, we need to remember that A2 β-casein is not without its own possible disadvantages. For instance, A2 β-casein can also cause lactose intolerance-like symptoms, though less so than from A1 milk. Human trials did not show any significant differences in total cholesterol, HDL cholesterol, or LDL cholesterol in those consuming A1 or A2 β-casein milk. Also, A1 milk was found to have a more hypotensive effect than A2 milk. This suggests that A1 milk might be less harmful for patients with ischemic heart disease or heart failure than A2 milk.(1,3)

Similar to the above description, Greger(6) points out that the primary culprit causing many of the adverse effects of drinking conventional A1 milk and its products is the bovine casomorphin (BCM) that is broken down from A1 β-casein protein. He also notes that studies have shown that BCM does not form following the digestion of A2 β-casein. However, he reports that the studies that determined this were done using digestive enzymes derived from pigs or cows. When an experiment was done using human digestive enzymes, casomorphin was reportedly produced from both A1 milk and A2 milk. I need to point out here that I was unable to locate and review the study from which this last piece of information was derived, and so I do not know if BCM-7 was the specific casomorphin being measured.

Ellen Cutler Method (ECM)

In my clinical practice, I have had the opportunity to use ECM energetic testing and desensitization methods to determine what role milk and dairy products have in each individual’s optimal dietary plan. For most people, I have found that the healthiest dietary pattern is whole food and plant based.(7) I rarely find that milk and dairy products are a healthy choice. And in those complaining of an apparent ‘allergy’ to milk, I usually find that they are sensitive to the protein in the milk, most often the casein. I have seen dramatic improvements in the health of many of those individuals eliminating dairy products from their diet.

For those reluctant to give up dairy products completely, I have sometimes found that using dairy products that contain only A2 casein might be better tolerated. However, even when using, for example, goat or sheep cheese, I usually found it necessary to desensitize the individual for that particular milk from which it was made. Additionally, ECM testing usually finds taking a full spectrum digestive enzyme helps achieve the best results. I recommend Dr. Ellen’s Way ‘Digest Supreme’ at the beginning of each meal. I also recommend adding Dr. Ellen’s Way ‘G.I. Calm’ for those with gastrointestinal complaints. In these cases, some of those switching to A2 milk and dairy products report varying degrees of improvement in their complaint(s), and sometimes dramatically so.

In the case of infants, the best A2 milk is human breast milk. Even then, the mother’s diet may be introducing (non)nutrients to which the infant is sensitive. In these cases, it is best to change the mother’s diet and/or desensitize the infant to the breast milk.

Please be well, be healthy, and remember…

““How on earth can cow’s milk be considered an essential part of our diet when its purpose is to feed calves until they are old enough to be weaned?”

MS Liberty Forrest

Dr. Ellen


  1. “Beneficial Effects of Milk Having A2 β-Casein Protein: Myth or Reality?” at https://www.sciencedirect.com/science/article/pii/S0022316622001407
  2. “Differences Between Casein A1 and A2 Milk (Your Digestive Health Depends On It)” at https://gundrymd.com/casein-a2-milk/
  3. Effects of Conventional Milk Versus Milk Containing Only A2 β-Casein on Digestion in Chinese Children: A Randomized Study” at https://journals.lww.com/jpgn/fulltext/2019/09000/effects_of_conventional_milk_versus_milk.23.aspx
  4. “Does a Little Difference Make a Big Difference? Bovine β-Casein A1 and A2 Variants and Human Health—An Update” at https://www.mdpi.com/1422-0067/23/24/15637
  5. “Clinical evaluation of glutathione concentrations after consumption of milk containing different subtypes of β-casein: results from a randomized, cross-over clinical trial” at https://link.springer.com/article/10.1186/s12937-016-0201-x
  6. “Is the Casein in A2 Milk Healthier?” at https://nutritionfacts.org/blog/is-the-casein-in-a2-milk-healthier/
  7. “Why Vegan?” at https://drellencutler.com/june-2022-newsletter/

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, mitigate, or prevent any disease.

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