Humans, Rats, Dogs, cows, tigers and all other mammals have one thing in common. They suckle their young and provide nourishment by way of mother's milk. Of all these mammals very few are recommended by Ayurveda across species. These are Cows, goats, tigers, elephants and deer. Obviously only the cattle and goats are capable of being domesticated for the purpose of milk production. Of these it is only the cattle that make economic sense and viability.
The major constituent of Cow's milk is water and the other components are carbohydrate (Lactose), fats, protein and minerals. The percentage of the individual constituents vary depending on the breed of the cow. The recent protest carried out in Tamil Nadu opposing the ban on Jallikattu has thrown up a discussion on A1 and A2 variants in cow's milk. Human milk contains only A2 protein and is well accepted by the body and cows also produced only A2 milk several thousand years ago before they were completely domesticated.
Difference between A1 and A2 Milk
There are many proteins in milk and these are broadly catagorized under two types: Casein and whey proteins. The casein family of proteins form the bigger chunk which account for more than 80% of the total proteins. This family consists of different types of casein proteins like α1 casein, α2 casein, β casein etc and each of these proteins has a different amino acid sequence. Amino acids are the building block of any protein and the order in which they are arranged in a protein is crucial to the function of that protein.
The difference in A1 and A2 milk is due to a difference in a single amino acid out of 209 in the β Casein protein. This difference was caused thousands of years ago due to a mutation or change in the gene responsible for making this protein. As a result of this mutation the 67th amino acid of the β Casein changed from proline to histidine. The milk that contains this mutated protein is known as A1 milk. This change caused a loss in stability of the β casein because histidine did not interact well with the neighbouring amino acids and therefore the stomach enzymes caused this mutated A1 protein to break into 3 fragments. One of them contained 7 amino acids and is known as Beta casomorphin 7 or BCM-7 which is not digested well by many people. BCM-7 is the culprit held responsible for several issues like type 1 diabetes, heart disease, autism, allergies, Schizophrenia etc.
Mutation leading to A1 milk is said to have started in Holstein cows and transmitted to the other breeds because Holstein was used to improve the other breeds of cows. When India adopted the foreign breeds, the mutated gene spread to the indigenous cows due to cross breeding and due to artificial insemination using Semen from Holstein Bulls.
Indian Desi Cows
Pure Indian Cows or the Desi cows have the gene for A2 milk. Genes come in pairs - one from the cow and one from the Bull. Cross breeding with foreign Holstein cows which contain A1 gene results in the progeny having A1/A2 genes and subsequent cross breeding results in A1/A1 cows.
Now that awareness has been spread about the harmful health effects of A1 milk, efforts need to be taken to eliminate the A1 gene from our cattle pool. This can be done by consciously breeding cows with the gene for A2 milk. Indian Bulls are A2/A2 and even if bred with A1/A1 cows we will have A1/A2 cows . Subsequent breeding of these cows with A2/A2 bulls have a 50% chance of producing A2/A2 cows and a few generations of selective breeding will give us majority A2/A2 cows. This could take a few years but will be worth the effort.