Change is key to human evolution but tampering with nature can cause unpredictable results. The same applies to our food, including milk and dairy. Industrialisation and increased demand for milk has led to cross-breeding, creating genetic variants.
There are two varieties of cows based on their genes: the high yielding one that produces A1 milk protein and the other that produces A2 milk protein. Recently, a relationship between disease risk and consumption of A1 or A2 genetic variants has been identified. Studies suggest that milk from cows with A2 genes are far healthier than their A1 counterparts.
Evidence linking A1 milk to ill-health is building up. These include conditions like type -1 diabetes, cardiovascular disease (IHD), delayed psychomotor development among children, autism, schizophrenia, sudden infant death syndrome (SIDS) auto-immune diseases, intolerances and allergies. There are certain people who are at a higher risk than others. Those with digestive disorders like stomach ulcers, ulcerative colitis, Crohn’s disease, Celiac disease, on long term medication or antibiotic treatment are at higher risk. This may also explain the growing sentiment against dairy and increased number of people opting for vegan diets.
Milk with A2 protein, on the contrary, is known to have several health benefits. In fact, the health benefits and virtues associated with dairy and milk in our traditional texts are accrued from the A2 milk. The milk variety has been shown to prevent obesity among children and adults, improve brain function, promote digestion and increase breast milk production in feeding mothers.
The prevalence of A1 and A2 protein varies from one herd of cows to another and also between countries. A1 gene is found mainly among cattle in the western world, predominantly in the North European region (Friesian, Ayrshire, British Shorthorn, and Holstein) while the Asian, traditional Indian and African cattle do not produce the A1 gene. Cross breeding of Asian and African cattle with European cattle in last few thousands of years, may have led to the presence of A1 genes in the cross bred species.
A2 gene, on the other hand, is found only in a few old species of cows, which haven’t been genetically altered — Channel Island cows, Guernsey and Jersey, Southern French breeds, Charolais and Limousin, Zebu original cattle of Africa and the Gir cow from India. Most dominant cows of today possess A1 genes, while the low yielding Indian Gir cow, on the verge of extinction, possesses the A2 genes. Human milk, goat milk, sheep milk and other species are ‘A2- like’. The only way out for an individual is to look out for organic milk, preferably, from traditional Indian (Desi) cows.
Author is a clinical nutritionist and founder of http://www.theweightmonitor.com and Whole Foods India