A1 milk is obtained from cows like Jersey, Holstein, etc breed which are of Western origin. These cows do not have a hump on its back. Whereas A2 milk is obtained from Indian origin cows which has a hump on its back like Gir, Sahiwal etc.
There is a considerable difference in the chemical compositions of A1 and A2 milk like the difference in the ratios of lactose (carbohydrate component) and fatty acids (fat component) in both milks. However, it is the protein component in the milk that differentiates the two from each other in terms of quality. A1 and A2 milk contain different kinds of beta casein protein.
When our body tries to breakdown casein in A1 milk, a chemical called BCM-7 (Beta-casomorphine-7) is released, which is responsible for several undesirable health consequences like the morphine-like effects on the Central Nervous system, Neuro disorders like cognitive disorders which affect learning ability in children. Additionally, Histidine is also released which causes kids to tend to develop allergic dermatitis (allergy on the skin), allergic rhinitis (running nose) allergic cough and asthma.
Moreover, carbohydrate and fat in A1 milk cause obesity, diabetes and also promote the growth of unhealthy bacteria in our intestine, leading to reduced immunity.
Many studies showed that A2 milk improves immunity, reduces the risk of type 1 diabetes & heart disease. A2 Milk from Indian origin cow outweighs the potential risks caused by A1 Milk.