What is A2 versus A1?
Milk contains two main proteins—whey and casein. A key type of casein, beta-casein, exists in two forms: A1 and A2. While most mammals naturally produce only A2 beta-casein, cows are the exception—many produce A1, A2, or a combination due to genetic variation. This matters because A1 beta-casein may release a compound during digestion called β-casomorphin-7 (BCM-7), which has been studied for its potential effects on digestion, inflammation, and neurological function. A2 beta-casein, by contrast, is digested differently and is less likely to release BCM-7. Some people with dairy sensitivities report improved digestion with A2-only milk, suggesting the issue may stem from A1 proteins rather than lactose. At Countryside Mercantile, we proudly source milk from Guernsey cows, known for producing pure A2/A2 milk and offering a rich variety of milk components.