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A Legend-DAIRY Guide to Milk Allergies, Sensitivities, & Intolerances

by Kate Daugherty, MS, CNS, Functional Nutritionist

Different types of dairy have different types of proteins (whey and casein) and milk sugars (lactose). Each type of protein affects our body differently; certain individuals are sensitive to all of the proteins or sugars. However, it is possible that we have a sensitivity to one milk protein and not the others. An elimination diet can help uncover where your individual tolerance lies.

Here is our guide to understanding dairy ISSUES.

Dairy Sensitivity, Intolerance, and Allergy what is the difference



Some people react to the proteins in milk; but it is far more common that you are sensitive to the sugar in milk: lactose. In order to break down lactose, we need an enzyme called lactase. Somewhere between 20-80% of people don’t produce enough lactase (after infancy) for this process to occur. Thus, we are faced with the problem of LACTASE INSUFFICIENCY; which is often mis-labelled as a milk allergy.

Bottom Line: If you are lactose intolerant: you do not necessarily have a milk allergy; you have an inability to breakdown lactose sugar due to lack of enzymes. This is NOT an immune reaction.

Side note: RAW dairy contains the lactase enzyme; pasteurization kills this enzyme. Many lactose intolerant individuals may find they can comfortably and reliably consume raw milk or cheese without incident. Another option is supplementing with lactase (this enzyme is often added to “lactose-free” products to digest the sugar before YOU consume it).

Poop Color Chart - What color should poop be? Things to know about your poop.



In cow’s milk dairy, there are six types of milk protein. Eighty-percent are casein, and twenty percent are whey.


Casein protein is slower-digesting and has several subtypes: A1 beta-casein, A2 beta-casein, and K. The amounts of each subtype can vary from species to species as well as amongst breeds. As milk is processed into yogurt, cheese, or ice cream the ratios of casein:whey also change.

Within the casein sub-types, the A1-beta is the most common in American holstein cattle. The A1 beta-casein creates a peptide called beta-casomorphin-7 that has opiate-like activity and histamine releasing properties. This peptide is closely correlated with heart disease and Type I diabetes. In children with autism, a Gluten-Free/Casein-Free Diet is regularly recommended as a first-line intervention.

(Another side note/fun fact: I've been interested in this for years! I wrote my undergraduate thesis for my neuroscience degree on the GF/CF Diet for Autism Spectrum Disorders #nerdalert #classof2013 )

Additionally, A1 beta-casein can cause gastrointestinal symptoms similar to those seen in lactose intolerance. We return to the question of dairy sensitivity: could it be the PROTEIN in milk more than the milk sugar that we respond negatively to?

Alternatively, sheep, goats, and jersey cows have primarily A2-beta casein.

Sheep and Goat’s dairy as well as milk from Jersey Cows has far less, and often zero, A1 beta-casein. This alternative protein profile means goat, sheep, and Jersey Cow milk may be a suitable alternative for adults or children who cannot tolerate cow’s dairy. Certainly, cross-reactivity can still be an issue.

Goat Dairy and A2 Casein
Goat and Sheep Milk has almost zero A1-Beta Casein

Milk Allergies and Proteins Beta-Casein Whey

For the purpose of a casein-free diet in children or when addressing hormonal-imbalance, I recommend first eliminating dairy completely and then systematically testing reintroduction of goat’s cheese and milk before moving on to select cow's milk. If raw milk is an option, this is perhaps the “best” dairy to include in a sensitive diet. However, there are commercially available milks that do not have A1 beta-casein. Find them marketed proudly as "A2 Milk" >>



While dairy can be inflammatory and/or allergenic; there is still a valuable place for some dairy protein in a nutritionally balanced diet. If tolerated, whey protein is an optimal choice when isolated. Whey protein has a superior amino acid profile and is more easily digested and absorbed. It also has benefits in supporting the body’s glutathione production.

Whey has higher concentration of the amino acid cysteine. Supplementation with whey protein has demonstrated improved performance recovery, improved muscular strength, and improved physiological adaptation in both resistance and endurance training. In addition to use for sport, whey protein supplementation is indicated for Parkinson’s Disease and Sarcopenia.

If you are using a powdered protein supplement in your daily diet, we recommend choosing a Grass-Fed Whey Isolate with no filler ingredients. Because the supplement industry is regulated by different standards, you are best served by choosing a product that has third-party verification. Pharmaceutical-grade supplements are just that: they meet the sourcing, testing, and production standards required to earn a pharmaceutical-grade label. << Learn More here >>



As you heal your gut, you may find that your tolerance to dairy improves. This oral tolerance happens as a result of tight junction integrity and removal of offending triggers. It can change in response to stress, trauma, infection, and dietary onslaught; so carefully monitor reintroductions and return to an elimination or anti-inflammatory diet as needed.

If dairy is just udderly off the menu, don’t despair! There are so many great brands offering dairy-free alternatives for milk, cheese, yogurt, and even ice cream.

Understanding Dairy Sensitivities and Proteins



Got other faves? Let me know in a comment! I'm always open to new finds.

ULTIMATELY, Dairy Sensitivities are complicated. If you are intolerant, it's worth exploring the components of milk to see where your threshold lies.

Want a free resource for understanding your diet and it's relationship to your moods and digestion? Click here to get Kate's 5 Day Food-Mood-Poop Journal!

Liver Detoxification Nutrients Needed
Modern day options in the "dairy" aisle


Want to work with a functional medicine doctor to run labs and assess nutrient status? Struggling with hormone imbalance, IBS, weight gain, mood changes? Let's look at BIOCHEMISTRY. Read more about Functional Medicine at The Facility here.

Not sure where to start?

CLICK HERE to schedule a FREE 15-Minute Consult with Kate to determine your best course of action!

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Dr. Mitchell Rasmussen - Doctor of Chiro
Kate Daugherty - Nutritionist - Function
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