Proline has a strong bond to a small protein called BCM 7, which helps keep it from getting into the milk, so that essentially no BCM 7 is found in the urine, blood or GI tract of old-fashioned A2 cows. On the other hand, histidine, the mutated protein, only weakly holds on to BCM 7, so it is liberated in the GI tract of animals and humans who drink A1 cow milk.
BCM 7 has been shown to cause neurological impairment in animals and people exposed to it, especially autistic and schizophrenic changes. BCM 7 interferes with the immune response, and injecting BCM 7 in animal models has been shown to provoke type 1 diabetes. Dr. Woodford's book presents research showing a direct correlation between a population's exposure to A1 cow's milk and incidence of autoimmune disease, heart disease, type 1 diabetes, autism, and schizophrenia.
So you see, A1 milk is still milk except that BCM 7 can cause problems.
Buffalo and goat milk is all A2 as I said so if you can get those. Otherwise, ghee made from A1 seems fine because it only involves milk fat and not proteins. Yogurt from A1 milk also seems to cause fewer problems than the milk itself.
