Is it Lactose Intolerance or A1 Beta-Casein Protein Intolerance?

by | Jan 17, 2019 | Nutrition | 2 comments

What is Beta-Casein?
Beta-Casein is a protein found in cows’ milk. There are two types of beta-casein in conventional milk, A1 and A2. A2 is said to be the original variant, as it existed prior to the appearance of A1. Regular cows’ milk in the US contains a mix of A1 and A2.

How are A1 and A2 Beta-Casein different?
A1 and A2 beta-casein stimulate different digestion processes. Digestion of A1 beta-casein can produce a peptide fragment called beta-casomorphin-7 (BCM-7). This binds to opioid receptors present throughout the body, which leads to inflammation in the gut and a delay in digestion. This results in increased gastrointestinal symptoms in some people, which can mimic lactose intolerance.

A2 beta-casein is digested fully. The structure of A2 beta-casein helps limit the release of BCM-7 on digestion.

If you have tried lactose-free milk and are still having GI symptoms related to milk, then A1 beta-casein may be your issue.

What is a2 MilkTM?
This milk is free of the A1 protein and BCM-7 related issues. It is from cows that only carry the A2 beta-casein gene.

Where can you buy a2 MilkTM?
Go to to see which supermarkets in your area carry a2MilkTM. In the Indianapolis area it is available at:
-The Fresh Market
-Earth Fare

You do not want to drink a2MilkTM if you have been medically diagnosed with lactose intolerance or have a milk allergy. It has the same amount of lactose as ordinary cows’ milk.

If you are looking for more information, go to

The information in this blog is not a substitute for professional medical advice, examination, diagnosis and treatment. Always seek medical advice from your physician or other qualified healthcare provider before altering your diet, starting a new treatment or making changes to an existing treatment.

Meet Valerie

Registered Dietitian Nutritionist - CDN, RDN

My name is Valerie Polley. I am a Indianapolis-based registered dietitian and owner of Blue Tree Nutrition. I consult with clients both local and far away.
I have a bachelor’s degree in nutrition from Purdue University and I have been practicing for 20 years.
I thoroughly enjoy helping clients through their gut health journey. I see a range of GI issues including, but not limited to celiac disease, IBS and SIBO. I also specialize in the FODMAP elimination diet.

Subscribe for More Great Articles!

Subscribe via email to be notified of new articles, healthy recipes and helpful tips.