Donate Deakin
Not currently recruiting

Why is this important?

There are two main types of beta-casein proteins found in cow’s milk – A1 and A2. A2 beta-casein is thought to be the original beta-casein protein, whereas the A1 protein has only emerged in dairy products after a mutation that occurred in cows a few thousand years ago. We are very interested in the emerging evidence regarding the differences between the A1 and A2 dairy proteins and their possible impact on health outcomes. As many of the pathways that appear to be affected by the A1 protein (e.g. inflammation, oxidative stress and gut health) are also of central importance in mental health, we are interested in testing the possible impact of these dairy proteins on both physical and mental health. Given the widespread consumption of dairy products, we feel that this research may have important implications for public health and may also produce insights to help consumers make informed choices in regard to their dairy consumption.

How are we doing this study?

To investigate the differences between these milk proteins, we are running a 16-week double-blinded, randomized, controlled trial at University Hospital Geelong. We are currently recruiting women with low mood from the Greater Geelong and Melbourne regions. Participants will be provided with milk and cheese to consume in place of their usual dairy products. Participants can assess their eligibility for the trial by completing the pre-screening questionnaire at

What are we hoping to find?

This study will be the first to evaluate the comparative effects of 16-week consumption of dairy products containing only A2 beta- casein versus dairy products containing both A1 and A2 beta-casein proteins on both physical and mental health outcomes. We will gather information on women’s symptoms of psychological distress, depression, anxiety and stress. We will also collect stool and blood samples from participants to reveal differences, if any, on the gut microbiota, gut symptoms, body composition, cognition, biomarkers of immune function and oxidative stress, health related quality of life and sleep.

The a2 Milk Company has provided in-kind funding for this trial but has had no input into the conduct, analysis or publication of the study results.