But lately, some have started to question which milk is best for optimising health and well being, following the release of findings from scientific studies about the effect of different milk proteins on human health. The focus of some recent scientific debate has been on the milk protein called beta-casein, which is described below.
What is milk made up from?
Cow's milk is made up of water, the milk sugar called lactose, milk fat, milk protein and various vitamins and minerals. In fact, milk is one of the richest sources of the mineral calcium, which we all know is needed for healthy bones, teeth and muscle function.
Cow’s milk has 2 main types of protein. The first is casein, which makes up around 80% of all the protein in milk and the rest is whey protein. Most people involved in the health and fitness industry know a lot about whey protein, but casein protein remains a mystery to many. Casein protein can be broken down further into 4 groups, but the one of interest in the current debate is beta-casein. Beta-casein makes up about 30% of the total protein in cow’s milk, or around ½ a teaspoon per glass. Beta-casein itself is further broken down into two main forms: A1 and A2 beta-casein.
A2 beta-casein is the original form of the beta-casein protein found in milk. Around 5 to 10 thousand years ago, a mutation in the A2 genes caused the appearance of the A1 type in some European cows. Eventually, A1 beta-casein distribution spread and many cows with the genes to produce A1 beta-casein were bred for milk production. Today, some dairy farmers in Australia, New Zealand and in the UK want to produce milk with the original A2 beta-casein protein, and so are choosing and breeding cows with genes to produce A2 beta-casein.
How is A2 Milk produced?
A2 cows are specially selected to produce A2 Milk because they have the specific genes in their DNA to allow them to produce milk containing only the A2 variant of beta-casein. Farmers can identify cows that produce the A2 type of beta-casein by a simple and non-invasive DNA test which analyses hair from each cow. These cows are then milked separately to manufacture A2 Milk.
Is it healthier to drink A2 Milk?
All dairy milk is good for nutrition and health and so the National Health and Medical Research Council recommend that milk be consumed daily as part of a well balanced diet. Drinking A2 Milk offers the benefit of avoiding the A1 beta-casein and this could be important for some people. This could be because some scientific studies published in science journals show associations between A1 beta-casein and the development or aggravation of certain medical conditions such as type 1 diabetes and coronary heart disease. Another reason could be that the European Food Safety Authority in 2009 published a report on beta-casomorphins (which includes BCM-7) and health, which suggested BCM-7 can have negative effects in the body. More recently, 2 other studies (a, b) have found cow's BCM-7 in the blood of both breast and formula fed babies, suggesting that BCM-7 can be transferred to an infant by a mother.
Should I be drinking A2 Milk or who is this milk suitable for?
A2 Milk can be consumed by almost everybody apart from those with cow’s milk protein allergy or lactose intolerance. A2 Milk contains just as much lactose as a regular glass of milk. But, for people who have an intolerance to milk unrelated to lactose intolerance and those prone to certain medical conditions, there may be some benefit from A2 Milk. A2 milk also contains just as much calcium as A1 milk.
In conclusion, most milk brands sold in supermarkets contain a combination of the A1 and A2 type beta-casein proteins, whereas A2 Milk contains only the A2 type. A2 Milk is available in all major Australian supermarkets. Drinking A2 Milk can help avoid possible reactions allied with BCM-7. Research demonstrates that there may be benefits for heart, immune and digestive health associated with reducing consumption of A1 beta-casein.