These health problems are linked to a tiny protein fragment that is formed when we digest A1 beta-casein, a milk protein produced by many cows in New Zealand, Australia and other western countries. Milk that contains A1 beta-casein is commonly known as A1 milk, whereas milk that does not is called A2. Originally all milk was A2 until a mutation affecting some European cattle occurred some thousands of years ago.

Herds in much of Asia, Africa and parts of southern Europe remain naturally high in A2 cows. A2 milk from selected cows is now marketed in much of Australia, and in parts of the USA and New Zealand.In Devil in the Milk Keith Woodford brings together the evidence published in more than 100 scientific papers. He examines the population studies that look at the link between the consumption of A1 milk and the incidence of heart disease and Type 1 diabetes; he explains the science that underpins the A1/A2 hypothesis; and examines the research undertaken with animals and humans. The evidence is compelling: we should be switching to A2 milk.This is an amazing story, one that is not just about the health issues surrounding A1 milk, but also how scientific evidence can be moulded and withheld by vested interests, and how consumer choices are influenced by the interests of corporate business. Devil in the Milk is a book of enormous public importance.