For every article espousing the dangers of consuming casein A1, there’s one available to refute it. However, there are a few facts that can’t be denied.
The original research in 1990 continues jointly with the University of Auckland-based Liggins Institute and AgResearch, a nationally owned research institute supporting New Zealand’s agriculture. They have proven that β-casomorphin-7 (BCM-7) is released by digestion of A1 casein. Several studies have shown that BCM-7 has opioid and cytomodulatory properties and is actually treated by the body as an opioid.
Studies by Dr. Reichelt in Norway and Dr. Cade at the University of Florida, among others, found that urine samples from people with autism, PDD, celiac disease and schizophrenia contained high amounts of the BCM-7. It has been suggested that the amounts of this peptide may also be elevated in other similar disorders such as chronic fatigue, fibromyalgia and depression based on the reported benefits of a casein-free diet.
Other studies have shown a proven connection between milk containing A1 β-casein and post-dairy digestive discomfort and cognitive impairment. A study published in 2016 in the Nutrition Journal concluded that the consumption of milk containing A1 β-casein was associated with increased gastrointestinal inflammation, worsening of post-dairy digestive discomfort, and decreased cognitive processing speed and accuracy. The results of the study showed that these symptoms were all avoided by drinking milk that contained only the A2 β-casein.
Finally, Dr. Steven Gundry has several examples of patients responding favorably to dairy products containing only A2 casein. While many patients believed that they were lactose intolerant, anecdotal evidence shows that it was merely the A1 casein. In his book, The Plant Paradox, he shares the story of a patient that was convinced by a friend to eat yogurt that wasn’t A2, and the symptoms of her rheumatoid arthritis returned that evening.
While A1 casein is clearly a problem, it’s not the sole issue with milk. For instance, a study out of Indiana University, published in the Indiana Journal of Endocrinology and Metabolism, showed an association between dairy intake and early onset of puberty.
Another study published in the Journal of Nutrition in 2012 showed a direct correlation between increased consumption of skim milk, whey and casein and an increased BMI in teens. Yet, none of the study’s funded by the dairy industry found any concern.
The head of the Obesity Prevention Center at Boston Children’s Hospital and the chair of Harvard’s nutrition department published an editorial in the journal Pediatrics in 2013 that suggested humans shouldn’t be drinking another animal’s milk.
Breast Surgery Chief of California’s Seton Medical Center, Dr. Robert Kradjian, reviewed archives of medical and scientific journals and found that milk is not the “perfect food” it is reported to be. He found that many childhood disorders were, if not induced, certainly aggravated by an increased intake of dairy products, including but not limited to allergies, ear and tonsil infections, bedwetting, asthma, intestinal bleeding (lesions), colic and childhood diabetes.
The American Academy of Pediatrics advises parents not to give their children dairy milk before their first birthday. Dr. Frank Oski, former Chief of Pediatrics at Johns Hopkins University Hospital and the author of Don’t Drink Your Milk, believes that milk should not be given to children to drink, ever. Since milk has been associated with iron deficiency anemia, occult gastrointestinal bleeding and various manifestations of food allergies, he believes it would be prudent to recommend that milk not be consumed at all.