Introduction
Milk is a popular dietary staple in many western countries. Sources of milk and milk products include cows, sheep, camels, goats, and others. Alternative sources that do not involve animals include soy, coconut, almond, flax, rice, and hemp.
Recently, a new type of cow’s milk has appeared in dairy aisles. This product, called A2 milk, has garnered attention from both consumers and scientists. Supporters of A2 milk claim that it is easier to digest and absorb than other types of milk.A2 milk was designed to help those who may have a sensitivity to the A1 protein in cow’s milk.
This article provides an overview of A2 milk, its possible health benefits, and current research (in India) surrounding the product.
What is A2 milk?
Beta-casein, which makes up 30% of milk protein, exists in many forms. The two most common forms are A1 and A2. A1 milk is produced by cows present in the United States and northern European countries. A2 milk only contains the A2 variant of beta-casein protein which is similar to that found in breast milk, instead of the A1 form. Cows with the A2 gene only produce A2 milk and are found in herds of Asia, Africa, and parts of Southern Europe. Jersey, Guernsey, Normande, and Brown Swiss breeds have a higher percentage of A2 genes compared to Holstein. As of 2017, about 700 liters of milk a day were produced in brazil through Gir cows, a breed originally procured from India, but which is now also being exported to India.
Some farmers have transitioned to being an A2 herd, but this can take many generations depending on the status of your herd, A1 and A2 beta-casein are genetic variants of the beta-casein milk protein that differ by one amino acid. Agentic test, developed by the A2 Milk Company, determines whether a cow produces A2 or A1 type protein in its milk. An A2A2 animal, bred to another A2A2 animal will always have an A2 offspring. Cows that are A1A2 or A1A1 will not produce A2 milk.
Health effects
The European Food Safety Authority (EFSA) reviewed the scientific literature and published their results in 2009.
As part of their evaluation, the EFSA looked at the laboratory studies that had been done on bovine β-casomorphin 7 (BCM-7) that found that BCM-7 can act as a weak opioid receptor agonist. The EFSA found no relationship between any disease and drinking milk with the A1 protein. In most of animal studies, BCM-7 was not administered orally, as humans would be exposed to it, but rather was given to animals by injection into the peritoneal cavity or directly into the spinal cord or brain. Symptoms of stomach discomfort, such as gas, bloating, and diarrhea that occurs after consuming dairy products, are typically attributed to lactose intolerance.
A pair of 2020 papers from Purdue University and the University of Auckland suggested that people with lactose intolerance experience significantly fewer symptoms from consuming A2 milk versus regular milk. A formula with only the A2 milk protein may be a helpful alternative for babies with milk-related tummy discomfort.
Literary Work
Publication of a book, “Devil in the Milk” by Keith Woodford, about A1 beta-casein and its perceived dangers to health, boosted sales of milk with predominantly A2 protein.
This groundbreaking work is the first internationally published book to examine the link between a protein in the milk we drink and a range of serious illnesses, including heart disease, Type 1 diabetes, autism, and schizophrenia.
These health problems are linked to a tiny protein fragment that is formed when we digest A1 beta-casein. All milk was once A2, until a genetic mutation occurred some thousands of years ago in some European cattle.
Geographical Significance
The percentage of the A1 and A2 beta-casein protein varies between herds of cattle, and also between countries and provinces. While African and Asian cattle continue to produce only A2 beta-casein, the A1 version of the protein is common among cattle in the western world. The A1 beta-casein type is the most common type found in cow’s milk in Europe (excluding France), the US, Australia and New Zealand.
On average, more than 70 percent of Guernsey cows produce milk with predominantly A2 protein, while among Holsteins and Ayrshires between 46 and 70 percent produce milk containing both the A1 and A2 proteins. It is sold mostly in Australia, New Zealand, China, and the United States. It was sold in the United Kingdom between 2012 and 2019.
Harnessing Potential of A2 Milk in India
The screening for the status of A2/A1 allele of beta casein in different species or breeds in India revealed the frequency of favorable A2 allele across Indian native cattle breeds is 0.95 whereas for crossbred and taurine breeds it is nearly 0.70. Even the breeding bulls being used for artificial insemination, the frequency of A2 allele is 0.70. This indicates our native cattle breeds as well as the crossbred populations could be the best resource to meet the global demands for A2 milk.
Studies by the National Bureau of Animal Genetic Resources (NBAGR), Karnal, Haryana covering 22 desi breeds have established that the predominant genotype in India’s native cattle is A2A2, confirming that our indigenous cows and buffaloes produce A2 milk.
Red Sindhi, Gir, Rathi, Shahiwal, and Tharparkar do not have A1 allele or A1A1/A1A2 genotype. There is huge potential for enterprising dairy units to take advantage of indigenous cow/buffalo milk and cater to the growing demand of A2 milk and A2 milk based value-added products in the market.
Given its predominance in Indian cattle, there is no need for consumers to switch to A2 milk. By all counts and proven results, it is no doubt that A2 milk is one of the most rising concepts of veterinary science which has a high demand in the international market and can be proven beneficial for the farmers and local people of India.
Also, read | Processing Technologies for Improving the Nutritional Value of Dairy Products
Authors:
Anannya Singh1, Arukshita Rana2 & Brijesh Nanda3
1. Ist Year B.V.Sc. & A.H. Scholar, Apollo College of Veterinary Medicine, Jaipur
2. Ist Year B.V.Sc. & A.H. Scholar, Apollo College of Veterinary Medicine, Jaipur 3. Assistant Professor, Department of LPM, Apollo College of Veterinary Medicine, Jaipur
