Milk- You decide

We're all familiar with regular, low-fat or skimmed cow's milk but there are a growing number of variations of milk on the market, such as unhomogenised and A2 milk. Confusion surrounds the types of milk available, and there are many arguments to suggest the advantages or disadvantages of a particular product.

Rather than becoming swayed by the media hype or debates surrounding milk, you decide.

A1 vs. A2 milk:
Milk contains six major proteins. Four are casein proteins, making up 80 per cent of milk, and the other two are whey proteins. One of the major caseins present is beta-casein. There are several types of beta-casein, but the two main types are beta-casein A1 and beta-casein A2.
Foods Standards Australia notes that certain breeds of cows, such as Friesians, produce mostly A1 milk, whereas other breeds, such as Guernsey and Jersey cows, sheep and goats, produce mostly A2 milk. Milk produced in Australia and New Zealand is normally a mix of A1 and A2 milks.

Protein molecules of A1 and A2 milk are both chains of amino acids. But in the A1 molecule, one amino acid is different, creating a weak link. A2 researchers believe this weaker link initiates the chain to break, creating a small piece called Beta Casomorphin 7. This piece is able to move through the gut wall and into the blood, perhaps triggering disease. Research published in the New Zealand Medical Journal suggests a link between A1 milk proteins and the prevalence of heart disease, insulin-dependent diabetes, autism and schizophrenia. A2 milk has been shown not to contribute to these conditions. After extensive research the New Zealand Food Safety Authority determined that despite the correlation between A1 milk proteins and these conditions, there was insufficient evidence to suggest that this milk is harmful to humans. The review does not recommend that milk be taken out of the diet in light of these claims. A2 milk costs more than regular milk, but the fact that it can now be bought in a growing number of supermarkets is evidence of its increasing consumption.

Pasteurised and homogenised milk:
All milk sold in Australia is pasteurised, a process that heats milk to 72C for 15 seconds then rapidly cools it to below 4 degrees Celsius. While the process destroys harmful bacteria it also destroys many of the valuable enzymes that allow the body to properly digest milk, leading to lactose intolerance. It is illegal to sell unpasteurised milk in Australia; however, unpasteurised goat's milk is available in some stores, perhaps slipping under the authority radar. It remains a subject of contention that the consumer should be allowed to decide which form of milk they choose to buy- pasteurised or not, rather than have the legislation already in place.

Homogenisation of milk disperses the fat globules consistently through the milk, which is why unhomogenised milk has a layer of cream on the top; it is the milk fat, or cream, that has naturally settled. Unhomogenised milk is still pasteurised, but is better for the digestion and assimilation of nutrients into the body than homogenised milk. It is available in health food stores and some supermarkets.

Skim milk vs. full-fat milk:
Skim milk results from milk that has been treated to remove the fat. It still retains the same amount of calcium as full-fat milk but is unsuitable for children under five due to its low fat content. The Children, Youth and Women Health Service notes it does not have the correct balance of protein, fat and carbohydrates for normal growth. Skim milk is however sold in health food stores, the only difference being that it is usually organic or biodynamic. Organic milk has been pasteurised, but not chemically treated, so has a naturally shorter shelf life of around five days.

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