What’s A2 Milk, Anyway? Your Questions Answered

I recently noticed A2 cow’s milk in the dairy case at my local supermarket here in Michigan. While it has been available in New Zealand and Australia for more than a decade, only recently has A2 cow’s milk appeared in the United States, initially in California. As I was looking at the varieties available (whole, 2%, 1%, fat-free) in half gallon cartons, a nearby shopper asked, “What’s A2 milk, anyway?”

As A2 cow’s milk is being rolled out across America, consumers are curious about this dairy product. Read below for answers to some frequently asked questions.

What is A2 cow’s milk?
Cow’s milk is a source of high quality proteins, casein and whey. Casein includes several variants, notably A1 and A2 beta-casein. The content of these beta-casein proteins in cow’s milk is determined by a cow’s genetic make-up. In the United States, most cow’s milk contains both A1 and A2 beta-caseins. However, certain cow breeds provide milk with only the A2 beta-casein protein and no A1 protein. This cow’s milk is called A2 milk. All other components of A2 cow’s milk and traditional cow’s milk, which contains both A1 and A2 beta-caseins, are identical.

What do proponents of A2 cow’s milk claim?
Proponents claim that A2 beta-casein is easier to digest than A1 beta-casein. They suggest that A1 beta-casein in traditional cow’s milk may cause or contribute to digestive discomfort and inflammation, which in turn increases the risk for some chronic diseases such as heart disease. The theory is that A2 milk may be an option for some people who believe they are lactose intolerant and experience discomfort after drinking milk, but in fact are not lactose intolerant or allergic to cow’s milk. For these individuals, any discomfort following cow’s milk intake may be related to sensitivity to A1 beta-casein.

Does traditional cow’s milk, which contains A1 beta-casein, increase inflammation and chronic disease risk?
Emerging research shows that consuming traditional dairy foods as part of a healthy eating plan has no adverse effects on inflammation. Further, intake of milk and other dairy foods is associated with reduced risk of high blood pressure, cardiovascular disease, and type 2 diabetes, as well as improved body composition and bone health.

What does the research say about the health benefits?
To date, only a few human clinical trials, one including a pilot study in 41 adults and another investigation in 45 Chinese adults who self-reported an intolerance to milk, have compared the digestive effects of A2 cow’s milk with traditional cow’s milk. While some differences in digestive responses are reported, the findings from these small studies are insufficient to draw conclusions. More research, particularly involving a larger number of participants, is needed to substantiate claims of A2 milk’s benefits beyond those of traditional cow’s milk.

Should individuals clinically diagnosed with cow’s milk allergy or lactose intolerance consume A2 cow’s milk?
Individuals clinically diagnosed with cow’s milk allergy should avoid all cow’s milk, including A2 milk, until advised to reintroduce it under the guidance of a physician. Regarding lactose intolerance, A2 cow’s milk has the same amount of lactose per serving as traditional cow’s milk. Strategies to help manage lactose intolerance include consuming reduced lactose or lactose-free cow’s milk, small amounts of cow’s milk at a time, yogurt with live, active cultures, and/or aged cheeses.

Is there a downside to consuming A2 cow’s milk?
There is no reason to suspect that consuming A2 cow’s milk is unsafe or harmful. Given their shared nutritional profile, A2 cow’s milk can be expected to provide the same science-based health benefits as traditional cow’s milk. A downside of A2 cow’s milk is its premium price tag, which is about twice that of traditional cow’s milk. Consuming A2 cow’s milk is preferable to eliminating dairy foods from your diet, or turning to plant-based alternative “milks”, both of which may increase the risk of nutrient shortcomings.

Bottom Line. More clinical research is needed to support a digestive advantage of A2 cow’s milk compared to traditional cow’s milk. Regardless of whether you choose traditional cow’s milk or A2 milk, cow’s milk is a nutrient-rich food providing nine essential nutrients and is associated with bone and other health benefits.