A1 milk: Should we worry?

In his recently published book ‘Devil in the Milk’, Keith Woodford claims a link between a protein in the milk we drink and a range of serious illnesses, including heart disease, type 1 diabetes, autism and schizophrenia.

He believes these health problems are linked to a tiny protein fragment that is formed when we digest A1 beta-casein. Milk containing A1 beta-casein is called A1, and milk that does not is called A2. Much of the milk we drink in New Zealand is A1 milk. So should we worry?

Concerns have been raised about the level of evidence to support the theories in the book.

Professor of Human Nutrition at Otago University, Jim Mann, comments: “Of course one cannot say there is nothing in the story, only that based on existing evidence the claims are flawed and the associations drawn are far from consistent. A1 milk has been drunk safely for thousands of years”.

The New Zealand Food Safety Authority also says milk, whether A1 or A2, remains safe to drink. “The book provides no evidence that would lead us to change our opinion that milk is anything but safe,” says Dr Donald Campbell, NZFSA Principal Adviser. “The book notes A1 milk has been a staple food in many parts of the world for more than 5,000 years and correctly points out the differing views on the possible health effects of its consumption.

“We are very concerned that statements about the safety of milk will create unnecessary fears, particularly for the parents of young children, and could lead some people to avoid a food where there is extensive international support for substantial nutritional benefits.

“It is our belief that there is no strong evidence of a link between A1 milk and human illness.”

The bottom line

While the scientists can’t totally refute the theories about A2 milk, we believe they are far from proven; at present they remain theories. There is not nearly enough evidence to suggest anyone should stop drinking any type of milk based on these theories. As part of a typical New Zealand diet, milk and dairy products are a readily accessible and important source of nutrients.