Q “I have been seeing more and more about A2 milk and its supposed health benefits. What is A2 milk, and is buying A2 milk worth the hype?”
A Melissa Townsend, Dietetic Intern, Tufts Medical Center, answers: “Casein is the main type of protein in cow’s milk. About a third of it is a type called beta-casein, which itself comes in two forms: A1 and A2. Different breeds of cows produce primarily A1 or A2—or a mix of both.
“A2 milk products are made from dairy cows that produce milk with only A2 protein. According to a recent systematic review, studies in animals and laboratory research have shown differences in the gastrointestinal effects of A1 and A2 milk. There have been fewer studies in humans.
“Some observational studies have associated milk containing A1 protein to increased risk for type 1 diabetes and heart disease, but the evidence is not conclusive at this time. Despite the controversies in the research, A2 milk may be beneficial for individuals who experience digestive discomfort after consuming cow’s milk. However, for individuals with a milk allergy or confirmed lactose intolerance, this product should still be avoided to prevent an allergic reaction or digestive discomfort.”