For some people, cow’s milk is simply devastating to health. We can wish for milk to be healthy because of its calcium and protein. We can hope that milk is better if it’s raw or organic.
We cannot get around the fact that one of the proteins in milk—A1 casein—is highly inflammatory for some people. In susceptible individuals, A1 casein is cleaved to form a powerful inflammatory opiate called casomorphin.
Not all cows produce A1 casein. It comes from Holstein and Friesian cows who are the dominant breeds in western Europe, North America and Australia. Dairy cows in Africa, Asia, Iceland and southern Europe make milk with mostly A2 casein. Those countries have a lower incidence of the conditions discussed below.
Milk that has predominantly or exclusively A2 casein is fine for most people. I find this in my clinic again and again. Goat’s milk is A2. And so is milk from Jersey cows. Dairy products that are mostly fat (such as butter) are also fine.
Which conditions suffer from A1 milk?
A1 casein is a trigger for Type 1 diabetes (the research around this is fascinating). It is also highly implicated in coronary artery disease and autoimmune disease.
Casein is involved (with gluten) in Autism and Schizophrenia. In fact, casomorphin is more damaging to the brain than the gliadorphin from gluten.
Casomorphin’s drug-like effect explains why it worsens anxiety and mood disorders, and causes cravings for dairy and sugar. Also why it causes withdrawal symptoms when it’s stopped.
The inflammation from A1 casein causes lymphatic congestion, metabolic suppression, and weight gain.
A1 milk can worsen acne, eczema, upper respiratory infections, asthma, and allergies.
It causes digestive problems, and not because of the lactose. Because of the massive histamine release from casomorphin.
Amongst my patients, I see quite clearly that A1 casein drives endometriosis. I believe it does so because it of its inflammatory, immune-disrupting effect. I have yet to see one case of endometriosis that did not improve by avoiding A1 milk.
Who is affected?
Some people are fine with A1 casein (they safely deactivate and eliminate the casomorphin). There is no simple test. It is not an allergy.
The problem occurs in people who A) lack the digestive enzymes to deactivate casomorphin, or B) have intestinal permeability which allows the reactive peptide to enter the blood stream. (Or both A and B.)
The clinical clue that I watch for is: Recurring upper respiratory infections as a child. Either ear infections, bronchitis or tonsillitis. Those infections were driven by A1 casein, and in adulthood, the same immune-disruption manifests as other inflammatory conditions.
What about raw milk?
Certain types of pasteurisation increase the amount of casomorphin in A1 dairy. Raw might be better, but it won’t solve the problem. We need to move away from Holstein cows.
- What Dairy Does to Periods
- New Zealand Professor Keith Woodford’s book Devil in the Milk: Illness, Health, and the Politics of A1 and A2 Milk. I spent an entire afternoon reading it (like a kid reading Stephen King), and I love Keith’s scientist-style of writing. When referring to various studies, he takes the extra step to “run the numbers” himself.
- 2014 peer-reviewed animal study in the European Journal of Nutrition: Comparative evaluation of cow β-casein variants (A1/A2) consumption on Th2-mediated inflammatory response in mouse gut. (Evidence that A1 beta-casein (but not A2 casein) generates inflammatory markers including myeloperoxidase (MPO) and interleukin-4 (IL-4).)
- 2014 human study: Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study.
- 2015 study: Epigenetic effects of casein-derived opioid peptides in SH-SY5Y human neuroblastoma cells.
- For a very interesting and detailed update from a dairy farmer, please read Heather’s post in the comments below.
Yours in Health,