The beta-casein evidence
strong and no alternative explanation for these betweencountry differences has stood the test of time.
A human clinical trial from Curtin University in Australia, recently published in the European Journal of Clinical Nutrition, found significant differences in digestive symptoms between milks containing A1 and A2 beta-casein. This has drawn attention back to some of the animal trials for explanations. For example, a New Zealand trial with rats, undertaken by AgResearch and published earlier this year, found increased levels of an inflammation marker MPO in the colon on the A1 diet. I am a coauthor on both the Curtin and AgResearch papers.
The New Zealand ‘‘AgRats’’
Mothers . . . can pass bovine BCM7 to their babies.
study also found, as expected, that the opioid effects of BCM7 from A1 beta-casein slowed down the passage of food through the rat intestines. Intriguingly, the A1 beta-casein also significantly increased the release of an enzyme called DPP4. The reason this is so intriguing is that the modern gliptin drugs, now widely used to control Type 2 diabetes, act by inhibiting this enzyme.
There is a lot more research of relevance, including arterial plaque in rabbits and increased antibodies to oxidised LDL in humans. I now have several hundred published studies of relevance in my database. There is no chance this issue will go away.
Next week, in the last of this series on A1 beta-casein, I will explain how to eliminate production of A1 beta-casein through breeding. I will also look again at the industry politics of A1 beta-casein and why the industry is so defensive. Disclosure of Interest: Keith Woodford receives royalties on his book on A1 and A2 beta casein and has previously acted as an independent adviser to The a2 Milk Company and other agri-food companies. He holds no shares in any milk company. Woodford is Professor of Farm Management and Agribusiness at Lincoln University. His archived writings, including more detail on the A1 beta-casein issue, can be found at keithwoodford.wordpress.com