Curtin University researchers have found milk drinkers could gain digestive health benefits by switching from milk containing the A1 protein.
Associate Professor Sebely Pal from Curtin’s School of Public Health and lead researcher said to date there had been no solid evidence to demonstrate that A2 milk had different gastrointestinal effects for humans than regular milk.
“The majority of the milk consumed in Australia contains the A1 protein and at present there is strong debate amongst health professionals and industry about the health effects of milk containing the A1 protein.
“Until recently, only animal studies had examined the impact of A1 type beta-casein protein in cows’ milk, compared to A2 type,” Associate Professor Pal said.
“Curtin’s project is one of the first, randomised studies to look specifically at how the two milk proteins affect humans’ gastrointestinal health in ordinary milk drinkers.
“The surprising finding in this study is that ordinary milk drinkers, who did not consider themselves to be milk intolerant, found they had slightly softer stools when they consumed A1 milk as opposed to A2 milk.
“This result may not be so important by itself, however these softer stools can be associated with increased abdominal pain, and this was highly significant.”
Bloating and voiding difficulty were also analysed as measures of participant discomfort.
“Interestingly, a sub-group of eight people who said they were intolerant to ordinary milk, also reported gastrointestinal benefits from the A1 beta-casein free diet,” Associate Professor Pal said.
“These preliminary results are very important for medical science and require follow up in other studies in different populations, like those with perceived intolerance to ordinary A1 beta-casein containing milk or people with irritable bowel syndrome.
“We will be seeking opportunities for further research projects with larger groups into the differences between the A2 beta-casein protein and A1 beta-casein protein in dairy products and their potential impact on human health.
“This study marks a significant step forward in understanding the A2 hypothesis,” Associate Professor Pal said.
The research was independently peer reviewed and published in the European Journal of Clinical Nutrition (EJCN) by the Nature Publishing Group.
The paper is available www.nature.com/ejcn/journal/vaop/ncurrent/full/ejcn2014127a.html.
The Curtin University research was funded by a grant from The a2 Milk Company™ Limited.
Notes to the Editor:
• The A2 milk protein comes from cows selected to produce only the A2 beta-casein protein and not the A1 protein. It is not a product of technological process or genetic engineering.
• Originally, all domesticated cows produced only the A2 beta-casein type protein. Owing to a genetic mutation in European herds, another milk protein emerged (A1) and spread throughout many countries.