Fact-check: Little evidence that 'foreign' A1 alternative to jallikattu cattle milk causes cancer

As with any other large-scale protest in India today, ongoing demonstrations in support of jallikattu in Tamil Nadu have also come with a swirl of social media messages promoting their cause. Among the several forwards asserting Tamil federalism or viciously trolling the People for Ethical Treatment of Animals that are bouncing around in Whatsapp and Facebook groups is a curious set of claims about A1 and A2 milk.

Variants of this message describe how the milk of indigenous cattle is superior to that of foreign cows. Foreign cows, the messages say, produce A1 milk, whereas Indian cows produce A2 milk. A1 milk, the messages say, cause a host of medical conditions including autism, schizophrenia, cancer and diabetes. The proposed ban on jallikattu, it is claimed, is a nefarious plan by PETA to help foreign medical companies profit from Indian illness.

But what is A1 and A2 milk and can A1 milk really cause cancer?

Simply put, cattle milk contains several proteins. One of these proteins is beta-casein. There are two variants of beta-casein, A1 and A2, from which the terms A1 milk and A2 milk derive. The A1 type of beta-casein breaks down to release a peptide called beta-casomorphin-7. (Amino acids are the building blocks of proteins and a peptide is a chain of two or more amino acids.)

A1 milk is found largely in northern European breeds of cattle, while Asian and African breeds produce A2 milk. This production is determined by their genetic makeup. This is why even though it is cows that produce milk, even the bulls of a particular breed are important in maintaining its production.

Since the early 2000s, there have been papers and articles suggesting that BCM-7 might actually be harmful to humans. But in 2009, the European Food Safety Authority conducted a review of literature available up to that date and concluded that any links were inconclusive. Most significantly, it found little evidence of BCM-7 having entered the blood stream.

What is clear is that even today, far more research is needed to establish clear links between BCM-7 and diseases. These studies will have to include testing of human subjects and long-term studies.

At best, BCM-7 might be linked with lactose intolerance and digestion issues. A study on 45 lactose-intolerant Chinese Han subjects found that they experienced greater symptoms of flatulence and bloating when consuming a mixture of A1 and A2 milk than when consuming only A2 milk.

A1 and A2 in India?

Setting aside BCM-7, how relevant is the A1 and A2 milk debate in India?

Whatsapp messages take particular care to note that the Jersey cow produces only A1 milk. The Indian government has promoted this breed of cows to farmers for its capacity to produce greater quantities of milk than indigenous ones.

Studies abroad have found evidence of A1 milk in cattle breeds of Europe, such as Holstein and Friesian cows. These studies also conclude that Jersey cows produce mostly A2 milk.

Indian researchers too have been studying A1 and A2 beta caseins. The National Bureau of Animal Genetic Resources even charges Rs 700 to determine the presence of either in milk samples.

In a 2011 survey of cows in India, the bureau concluded that five indigenous breeds – Gir, Rathi, Red Sindhi, Sahiwal and Tharparkar – have 100% A2 beta caseins. Other indigenous breeds, their study said, had up to 94% of this protein. It is not clear if the bureau analysed kangayams, the breed most commonly used for jallikattu, in its research.

The bureau also studied foreign cattle present in India and found, contrary to European and Australian studies, most foreign breeds of cattle produced up to 60% A2 beta-caseins and 40% A1.

Even supposing that one consumes milk only from foreign breeds present in India, the average daily consumption, notes Dr Abdul Samad, former dean of the Bombay Veterinary College, would be far less than that of people in European countries, where studies linking A1 beta-casein to diseases have been conducted.