Are You Affected by Dairy Intolerance (Lactose, Casein and Whey)?

Have you ever taken a food sensitivity test where dairy showed up in red or suspected that dairy is not your friend? Having a food intolerance is not fun. It can cause abdominal pain, discomfort and nausea. It also causes embarrassing symptoms like flatulence and diarrhea.

Those are the obvious signs that you feel in your gut and you associate those with the foods you ate. But what if I told you it is not all in your gut, if you react to foods?

Other symptoms linked to food intolerances include muscle or joint pain, headaches, exhaustion and even skin symptoms like rashes and eczema.

Dairy is just one of those foods that many people seem to be intolerant of. In fact, dairy ranks on No. 2 in terms of intolerances and a majority of people with chronic autoimmune conditions react to dairy, and that means the milk protein and not just necessarily lactose.

Let’s talk about the main components of milk that people react to: lactose, casein and whey.

Milk sugar (lactose) intolerance

It’s estimated that up to 75% of adults worldwide are lactose intolerant. That is 3/4 of the adult population. This is a big number and I feel it is quite safe to say that it concerns most of us.

Lactose is the carbohydrate “milk sugar” naturally found in most dairy products. Lactose intolerance is so common, you can buy lactose-free milk in your regular grocery store. Lactose-free products are treated with the enzyme “lactase” that breaks the lactose down before you ingest it. It’s this lactase enzyme that is lacking in most people who are lactose intolerant.

The lactase enzyme is naturally released from your intestine as one of your digestive enzymes. It breaks down the lactose sugar in the gut. When someone doesn’t have enough lactase, the lactose doesn’t get broken down the way it should. Undigested lactose ends up being food for the resident gut microbes. As they ferment the lactose, they create gases that cause bloating, flatulence, pain and sometimes diarrhea.

Lactose is in dairy but is in lower amounts in fermented dairy (e.g. cheese & yogurt) and butter. Steering clear of lactose isn’t that easy though. Among the obvious foods mentioned above, it is added to other foods like baked goods, soups and sauces. And if you’re taking any medications or supplements, check to see if it’s in there too, as lactose is a common ingredient in them.

If you have symptoms of lactose intolerance, keep an eye on food, medication and supplement labels.

Milk protein (casein & whey) allergy

Milk is a known, and common, food allergen. In Canada, it is considered a “priority allergen” and must be declared on food labels.

So, what are the allergens in milk? You’ve heard of “curds and whey?” Well, these are the two main proteins in milk. The solid bits are the curds (made of casein), and the liquid is the dissolved whey.

Unlike lactose intolerance, casein and whey can cause an actual immune response. It’s an allergy. And this immune response can cause inflammation. In fact, we don’t know how many people have these milk allergies, but most estimates put it far below that of lactose intolerance.

But as I mentioned above, especially people with autoimmune conditions do not want to aggravate their immune system even further by eating dairy. It’s best avoided in these cases.

Like lactose, these allergenic milk proteins can be found in other products too. They’re not just in dairy but are often in protein powders as well. (Have you heard of “whey” protein powders?)

Some of the symptoms of milk protein allergy differ from that of lactose intolerance; things like nasal congestion and mucus (phlegm) are more common here. And casein seems to be linked with belly fat. Isn’t that interesting? Could that be the reason you cannot get rid of your muffin top, despite all the right things you are already doing?

Interestingly, people who have gluten intolerance are often allergic to milk proteins like whey and casein as well. These can go hand-in-hand. They often cross-react in the body. Most people I see in my private practice need to get off both (gluten + dairy) to give their body a chance to recover.

Like lactose intolerance, if you’re allergic to casein and whey, keep an eye on labels so you can avoid these.


If you get gassy, bloated or diarrhea after eating dairy, you may have a lactose intolerance. If you often get a stuffy nose and mucus, then you may be allergic to casein and/or whey.

And this last insight might surprise you but dairy is not an essential nutrient. All the nutrients in dairy are available in other foods. If you experience these symptoms, you can try removing dairy from your diet. You may find improved digestion and fewer gut issues. Or you may find improved nasal congestion, or even less belly fat.

If you decide to (or have already) removed dairy from your diet, let me know your experience in the comments below.

If you like to speak with me to find out how you can get started, investigating whether or not you should avoid dairy, hop on a complimentary call with me. I have limited spots only, so make sure to book as soon as possible.

Book a call with me HERE


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