Diabetes, heart risk linked to NZ milk

By ANGELA GREGORY

New research has linked a common milk protein with increased rates of heart disease and childhood diabetes.

The study by Auckland medical researchers has been published in the latest issue of the New Zealand Medical Journal and suggests a strong link between consuming milk with A1 beta-casein- which most New Zealanders drink each day - and heart disease and Type 1 diabetes.

Emeritus Professor Bob Elliott and Dr Murray Laugesen looked at heart disease rates in 20 countries and diabetes rates in 19.

Medical experts say their research supports the need for more studies on the potential health risks of A1 milk.

All cows' milk in New Zealand contains the A1 beta-casein protein, although some herds are understood to be free of it.

Dr Laugesen said populations that consumed a lot of A1 milk showed a higher rate of heart disease. There was an even stronger correlation for childhood diabetes that required treatment with insulin (Type 1).

For the first time the researchers had looked at health data from the Channel Islands, where milk has either very low or zero levels of the A1 protein.

Guernsey Island showed the third-lowest rate of heart disease, behind Japan and France.

New Zealand had the third-highest rate of heart disease and the fourth-highest consumption of A1 milk.

Dr Laugesen said much French milk came from brown cows such as simmentals, which produced less A1, while the Japanese drank little milk.

He said more research was needed comparing people with heart disease and their consumption of A1 milk.

Dr Laugesen believed New Zealanders should have the choice of A1-free milk. But he said smoking, diets high in saturated fats and lack of exercise were all significant contributors to heart disease.

In the journal's editorial Professor Robert Beaglehole, of the World Health Organisation, and Professor Rod Jackson, of the Auckland Medical School, said the greatest short-term gains in controlling heart disease would still come from existing knowledge.

But they called for further research on A1, given its relatively high levels in New Zealand milk and the importance of the dairy industry.

It would be reasonably straightforward to change New Zealand dairy herds to produce only A2 milk if that was necessary, they said.

"The intervention would require no change in behaviour by New Zealanders and could be implemented with little personal difficulty for substantial health gain."

Dr Diana North, medical director of the Heart Foundation, said the "potentially exciting" research clearly showed an association between A1 beta-casein and heart disease.

But she agreed more research was needed to establish whether the protein actually caused the diseases.

Biotech company A2 Corporation, which is a partner with Fonterra in a patent for non-diabetogenic (non-A1) milk, said the research confirmed findings of earlier studies.

A2 Corporation chief executive Dr Corran McLachlan said A1 milk was probably the most powerful risk for heart disease yet identified.

Dr McLachlan claimed some farmers wanted to supply A2 milk but Fonterra was stopping them. Supermarkets were also reporting a demand for A2 milk.

He said A2 Corporation was in a legal dispute with Fonterra over whether warnings should be placed on A1 milk.

The company also wanted Fonterra to disclose all its information on links between A1 milk and health risks.

Last September, Fonterra said it had studied the effect of A1 milk on heart disease and found no link.

Yesterday, the company declined to comment on the new research.

A Ministry of Health spokesman said the research was of interest and would be looked at closely.

The ministry and the Food Safety Authority are expected to make a joint statement about the research today.

Herald feature: Health