NZ biotech A2 study links milk, heart disease

A link between heart disease and the consumption of milk protein beta casein A1 has been demonstrated in a study performed by Queensland researchers for New Zealand biotech company A2 Corporation.

Dr Julie Campbell's team at the Centre for Research in Vascular Biology at the University of Queensland fed rabbits either the A1 or A2 protein to examine the impact of the protein on the arteries.

"The results of Prof Campbell's tests showed a marked and significant difference in the heart disease outcome of rabbits depending whether they consumed A1 or A2 casein, said A2 CEO Dr Corran McLachlan. "The research demonstrates for the first time a direct link between the consumption of A1 casein and heart disease in an animal."

The results would be submitted to a major journal for peer review, he said, and would be made available after publication.

The bases for the study are epidemiological observations that consumption of beta-casein A1, one of the two major variants of the beta casein proteins in cattle, is strongly correlated to type 1 diabetes and heart disease. The other form of the protein, beta casein A2, does not appear to be linked to the conditions.

Results of epidemiological studies from the New Zealand Dairy Board and the Child Health Research Foundation and others have indicated that children who consumed predominantly A1 milk had a much higher risk of developing type 1 diabetes.

The difference between the two variants is one amino acid, and the alleles are co-dominant, meaning that if both are present in an animal, both are expressed. While Asian cattle varieties produce milk with predominantly the A2 variant, milk from European-derived breeds contain more A1 than A2.

About 30 per cent of dairy cattle in Australia and New Zealand produce pure A2 milk, and Corran said he believed there was a real market for pure A2 milk.

A2 Corporation was formed in 2000 to commercialise the opportunities arising from the A1 and A2 research. The company has rights to a series of patents that enable them to identify A2 cattle and produce A2 milk.

"The patents cover testing and sorting of cattle to produce pure A2 milk," explained McLachlan. He said the company would provide testing services and receive royalties from the sale of A2 milk as a condition of testing.

The company plans to market A2 milk as a consumer product initially in New Zealand, followed by Australia. McLachlan said he believed the company's research provided a tremendous marketing opportunity for the dairy industry to promote human health.

"We want to get A2 milk on the supermarket shelf so people can buy it," he said. He noted that in his opinion it would be particularly important to get children drinking it to prevent development of diabetes and heart disease later in life.

The company is also working with a number of researchers, including groups at the Baker Institute for Medical Research at the Alfred Hospital and the Howard Florey Institute at the University of Melbourne, as well as the UQ group, to further examine the links between A1 milk consumption, diabetes and heart disease. The studies include a number of animal studies as well as a human study.

NZ dairying giant Fonterra urged caution regarding A2 Corporation's findings.

"The science behind this research is complex -- the recent announcement that A1 milk consumption is linked with heart disease in rabbits needs careful consideration and review by experts in the field," said Dr Chris Mallett, Fonterra's director of corporate research and development, in a statement.

He noted that Fonterra had not been able to establish a link between A1 milk and heart disease.

However, McLachlan was philosophical about Fonterra's viewpoint.

"I'm not sure if we would ever convince Fonterra," he noted. "But I can understand their position."