Key takeaways:
A2 milk contains A2 casein protein but does not have any A1 casein protein.
The only difference between regular and A2 milk is the type of casein protein. A2 milk tastes just like regular cow’s milk and has the same vitamins and minerals. It is not lactose-free.
If you get gas or bloating from milk, get tested for lactose intolerance. If your healthcare provider says that lactose is not the problem, you may have A1 casein intolerance. In that case, A2 milk might be a potential alternative.
Some people have trouble digesting milk. Many assume their stomach issues are caused by lactose intolerance, but this is not always the case. It turns out a protein in milk called A1 casein can also cause symptoms such as gas and bloating and may be mistaken for lactose intolerance.
You may have noticed A2 milk in the grocery store. It does not contain A1 casein protein. But is it a promising alternative to regular milk? Here's what you need to know.
What is A2 milk, and how does it differ from other types of dairy milk?
A2 cow’s milk is a type of dairy milk that only contains A2 casein, which is a specific type of protein.
All cow’s milk contains casein, but casein has two variants: A1 and A2. Most milk that’s sold in grocery stores contains both A1 and A2 casein.
Other than the type of casein, A2 milk looks and tastes just like regular milk. It also contains the same amount of lactose as other cow’s milk (more on this later).
Regular milk vs. A2 milk nutrition
There are slight differences in vitamin and mineral content between regular milk and A2 milk, and these differences vary by brand. But overall, regular and A2 milk are nutritionally similar. You can choose A2 milk if you have trouble digesting regular milk.
Nutrient | Regular milk (1 cup) | A2 milk (1 cup) |
Calories | 122 kcal | 130 kcal |
Protein | 8 g | 9 g |
Fat | 5 g | 5 g |
Carbohydrate | 12 g | 12 g |
Calcium | 309 mg | 389 mg |
Potassium | 390 mg | 389 mg |
Sodium | 95 mg | 125 mg |
Vitamin D | 111 IU | 199 IU |
Can people with lactose intolerance drink A2 milk?
A2 milk contains the same amount of lactose as regular milk and is not meant for people with lactose intolerance. If you have lactose intolerance and drink A2 milk, you may experience symptoms like gas, bloating, and diarrhea.
If you have lactose intolerance, take lactase supplements before drinking A2 milk. Or buy lactose-free A2 milk.
The symptoms of A1 intolerance are often confused with lactose intolerance. So if you experience digestive symptoms after drinking milk, see a healthcare provider to get tested for lactose intolerance. If you don’t have lactose intolerance, you might have casein A1 intolerance.
Having an A1 intolerance may lead to similar symptoms like:
Gas
Bloating
Stomach ache
Cramps
Diarrhea
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Is A2 better for you than regular milk?
From a nutrition standpoint, A2 milk is not better for you. It has the same nutrients as regular milk. However, A2 milk might be better for people who have trouble digesting A1 casein.
One small study of 45 adults who may have had A1 intolerance compared the effects of drinking regular or A2 milk. The researchers found a link between people who drank A2 milk and:
Less stomach discomfort
Less inflammation
Better scores on a cognitive test
Given the small size and short duration of the study, more research still needs to be done to see if A2 milk is helpful in the long term.
A2 milk benefits
A2 milk is fairly new to the market, so there is little research on its potential health benefits. The only data currently available is around potential digestive advantages for people who may have A1 intolerance and is noted in the previous section.
That said, since regular and A2 milk have a similar nutrition profile, it’s possible that A2 milk can have the same benefits that have been linked to regular cow’s milk. These include:
Better bone health: Protein, calcium, and vitamin D are some of the nutrients in milk that are known to support healthy bones.
Lower blood pressure: Since the DASH diet (used to prevent and control high blood pressure) recommends 2 to 3 servings of dairy per day, milk can be part of this eating pattern. The calcium, potassium, and magnesium found in milk as well as in foods like vegetables, fruit, and whole grains can help lower blood pressure and heart disease risk.
Reduced colon cancer risk: Studies show a link between people who drink milk and a decreased risk of colon cancer. The protective effects are thought to come from calcium and vitamin D.
A2 milk side effects
Apart from digestive symptoms that may occur if you have lactose intolerance, some studies show that drinking cow’s milk in general can be linked to worsened acne and eczema flares.
There is no research yet on whether A2 milk specifically is linked to a higher risk for these conditions.
Who should not drink A2 milk?
You should not drink A2 milk if you have a lactose intolerance, milk protein allergy, or galactosemia, a rare genetic disorder where you can’t digest milk sugar.
The bottom line
A2 milk is cow’s milk that only has A2 casein as opposed to A1 and A2 casein. While A2 milk has the same nutritional value and the same taste as any other cow’s milk, some people report less digestive issues with A2 milk.
If you get gas and bloating from drinking regular milk, talk with a healthcare provider to find out if you may have lactose intolerance or A1 casein intolerance. After you know that answer, choose the milk that’s right for you.
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References
Barrubés, L. (2019). Association between dairy product consumption and colorectal cancer risk in adults: A systematic review and meta-analysis of epidemiologic studies. Advances in Nutrition.
FoodData Central. (2019). Milk, reduced fat, fluid, 2% milkfat, with added vitamin A and vitamin D. U.S. Department of Agriculture.
FoodData Central. (2023). 2% reduced fat A2 milk. U.S. Department of Agriculture.
Jianquin, S., et al. (2016). Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows’ milk. Nutrition Journal.
Kay, S. S., et al. (2021). Beneficial effects of milk having a2 β-casein protein: myth or reality? The Journal of Nutrition.
Pal, S., et al. (2015). Milk intolerance, beta-casein and lactose. Nutrients.
Song, M., et al. (2015). Nutrients, foods, and colorectal cancer prevention. Gastroenterology.
