A2 milk

[Guest guest]

Good milk bad milk? (Aug 2003)

Milk has always traded on its healthy image, but it looks like some milk might be better for us than others, and nothing to do with the fat content.

I am a producer on Radio 4's The Food Programme, and also have a daughter coming up for 2. Since having Jess I've been particularly interested in the links between diet and health. In terms of milk and dairy products I now think that organic is the way to go, as animals tend to be grassfed rather than fed on concentrated animal feed, and this changes the sorts of fat they produce in their milk to produce more of the good and less of the bad. Organic Guernsey or Jersey milk or butter for example would be high in CLA, an essential fatty acid, which is thought to be highly protective against different sorts of disease, whereas the milk from a conventionally-fed animal wouldn't be. Plus no pesticide or antibiotic residues.

While making the milk programme one of the most interesting stories to emerge was about a protein in milk called beta-casein and its possible impact on health.

The following might seem complicated, but bear with me. There are a number of different proteins in milk but in terms of the beta-casein the vast majority of mammals produce a type called A2. We do, goats do, wombats do, and originally all cows did as well. But sometime during the domestication process some cows started to produce a different beta-casein as well, called A1. Through selective breeding the cows we now rear for milk production – predominantly the black and white Friesian Holsteins – produce milk that is about 70% A1, and only 30% A2.

Until now this hadn't been thought to make any difference, but some doctors now think that it might. A paediatrician in New Zealand, a Dr Elliot, concluded that it was the A1 beta-casein in milk that was causing childhood diabetes in Polynesian children growing up in New Zealand.

Following on from his observations, a Dr Corrie Mclachlan also in New Zealand concluded that consumption of A1 milk exactly mirrored the rising incidence of heart disease in the developed world. As a consequence he set up a company called A2 Corporation to produce and sell 100% "A2" milk in New Zealand and Australia. To back up his claims that A2 milk is good for you he is taking the New Zealand dairy board, Fontera, to court this autumn to try to compel them to carry health warnings on ordinary A1 milk.

His claims have so far been dismissed by the international establishment both dairy and medical. The dairy industry stress that we have been drinking the same milk for hundreds of years with no ill effects (questionable, as the cows we now have are highly specialised compared to earlier centuries, so it may well be different). They dispute the significance of these findings, as they are based on epidemiology, not double blind trials. Dr Mclachlan claims that this proof based on animal trials will be published this month, but at time of writing it hasn't been. The dairy industry here say that even if this is the case, they would like to see proper scientific tests on humans before they take a view on the matter, although currently nobody is putting up any money to do these trials.

It has also been claimed that A1 milk is involved in autism. I spoke to Professor Shattock from the Autism Research Unit at Sunderland University about this. Part of their programme is aimed at a dietary management of the symptoms of autism, and the two big substances that they ask parents to withdraw from the diet are gluten and casein because when they are broken down during digestion they form opiod substances. In most people these do not pass through the gut wall, but in autistic children they do, and once in the circulation affect brain function. By withdrawing both casein and gluten these symptoms often disappear or become more manageable. They now think that because of the different structures of A1 and A2, it is only the A1 that causes the problems, and therefore it is possible, and even probable, that A2 milk would be safe for autistic children.

Professor Shattock was keen to point out that to his knowledge no research of any description has been done on the differences between A1 and A2 beta-casein and autism. But at an anecdotal level (which he stressed was not scientific proof) they have observed that a child at the unit whose behaviour improved after withdrawing milk entirely from his diet, and who remained improved following reintroduction of A2 milk.

In the UK we don't have "A2" branded milk, but Guernsey milk, through a quirk in history, is about 90% A2, and Jersey milk about 50% compared to the normal 30%. Plus both are full fat milks, so ideal for children under the age of 5 who should be on a full fat diet. You can buy Guernsey organic milk in Waitrose, ordinary Guernsey milk in Sainsbury's, and a mixture of Jersey and Guernsey in both and Tesco's. You can buy Jersey milk at Bumblebee, and I'm trying to find them a supplier for Guernsey. You can also buy goat's and sheep's milk there, both exclusively A2.

I spoke to all the people involved in this, and my gut feeling is that while the A2 Corporation has a commercial interest in marketing their product, the dairy industry also has a considerable vested interest in this theory not being true, because it would involve changing 90% of our dairy herd over to predominantly A2 producing cows at considerable cost to farmers and ourselves as well - the older breeds like the Guernsey aren't as high yielding cows as the highly specialised black and whites so milk prices would probably go up.

But for my money I now buy Guernsey, Jersey or sheep's milk for Jess when I can, although until they come up with a semi-skimmed version we're holding off for the time being ourselves.