Spotlight goes on milk's link to killer disease

Controversial implied claims of therapeutic benefits to people drinking A2 milk are to be canvassed today by food safety authorities.

The implied claims have included that A2 will not trigger some forms of heart disease, autism, schizophrenia and diabetes.

The Food Safety Authority (FSA) will tomorrow release a scientific literature review by former New Zealand Heart Foundation medical director Boyd Swinburn, on research into health differences between "ordinary" milk containing A1 proteins, and the A2 milk promoted by A2 Corp here and in Australia.

A2 Corp has avoided making therapeutic claims for the A2 milk it has launched on both sides of the Tasman, which would have to be substantiated with scientific research.

It has, however, made a lot of claims of potential health risks it says may be associated with "ordinary" milk, which contains a mix of A2 and A1 beta casein.

Dr Swinburn, now professor of public health nutrition at Melbourne's Deakin University, was hired by the FSA in May last year to review all available literature on research of possible links between A1 milk proteins and heart disease or insulin-dependent diabetes.

He was also to look at research linking beta casomorphin 7 (BCM 7) with asperger's syndrome - a form of autism - and schizophrenia.

A2 owns and licenses intellectual property that enables the identification of cattle producing milk with A2 protein which the company promotes as a "less risky" alternative to normal milk with either A1 casein or a mix of A1 and A2.

Digestion of the A1 variant of milk - found in most of the milk consumed in Western countries - in the gut releases the smaller molecule BCM 7, which A2 Corp claims is a trigger for type 1 (juvenile) diabetes.

About 70 per cent of the New Zealand dairy herd produces milk containing some A1 protein.

But the research promoted by A2 Corp has not so far persuaded health and food safety officials to require warning labels on milk.

"The evidence is not strong enough to change the health messages around milk or to require any special labelling on milk," the Ministry of Health's then public health director, Colin Tukuitonga, said last year.

Dr Tukuitonga was responding to two New Zealand researchers who compiled data from 20 affluent countries to publish a study in the New Zealand Medical Journal showing a relationship between the amount of A1 beta-casein and milk protein consumed in a country and the national rate of coronary heart disease.

The researchers said there was also a similar correlation between A1 beta-casein consumption and the rate of juvenile type-1 diabetes.

One of those researchers, Murray Laugesen, said A1 casein in milk and cream had been "significantly and positively correlated" with ischaemic heart disease, which results from a shortage of blood to the heart.

It is the number one killer in many industrialised countries and is usually caused by clogged or blocked arteries.

The study also confirmed 1999 work by Professor Bob Elliott, of Auckland, which linked juvenile diabetes with A1 proteins in milk.

But further animal research and clinical trials would be needed to compare disease risks of A1-free milk with ordinary milk, the researchers said.

The FSA said the study in the NZ Medical Journal was "inconclusive" and "not a reason for people to stop consuming cows' milk".

However, there is concern in the industry that publicity about the research might reduce consumption of dairy products. The outcome of the debate is seen as crucial to Fonterra credibility in marketing New Zealand milk around the world as a healthy food.

- NZPA