Lactose Intolerance vs. Dairy Sensitivity: Why It Matters & How to Find Out
Many people assume bloating, digestive discomfort, or sinus congestion after eating dairy means they’re lactose intolerant, but in functional medicine, we recognize that a dairy sensitivity could be possible. Unlike lactose intolerance, which is simply an enzyme deficiency, dairy sensitivity involves an immune reaction to dairy proteins like casein or whey. This immune response can contribute to chronic inflammation, digestive issues, skin problems, joint pain, and even hormone imbalances.
Lactose Intolerance vs. Dairy Sensitivity: Key Differences
Lactose Intolerance – The body lacks lactase, the enzyme needed to digest lactose (milk sugar). Symptoms are mostly digestive (bloating, gas, diarrhea) and improve with Lactaid or lactose-free dairy.
Dairy Sensitivity – The immune system reacts to casein or whey proteins, triggering inflammation that can affect digestion, skin, sinuses, and more. Lactaid won’t help, and even small amounts of dairy may cause symptoms.
How to Identify a Dairy Sensitivity
1) Food Sensitivity Test
Functional medicine tests (like IgG or mediator release tests) can indicate immune reactions to dairy proteins. While not 100% definitive, they can help guide an elimination plan.
2) Elimination Diet (Gold Standard)
The best way to know if dairy is causing symptoms is to completely eliminate it for 3-4 weeks and then reintroduce it. If symptoms disappear and return when dairy is added back, you likely have a sensitivity.
3) Modified Elimination Diet
Some people react more strongly to certain dairy types. Try eliminating all dairy, then reintroduce in stages:
Ghee (no casein/whey) → Aged cheeses (low lactose, high casein) → Goat/sheep dairy (different proteins) → Milk/yogurt (high casein + whey)
If you react to all forms, full dairy elimination is best. If you tolerate some but not others, modify accordingly.
Managing Dairy Sensitivity
Go Dairy-Free for a Healing Period – Give your gut 4+ weeks to reduce inflammation.
Support Gut Health – Use probiotics, digestive enzymes, and gut-healing nutrients (L-glutamine, collagen, aloe).
Find Nutrient Alternatives – Get calcium, vitamin D, and healthy fats from greens, nuts, seeds, fish, and fortified non-dairy milks.
Be Mindful of Hidden Dairy – Read labels! Whey, casein, and milk solids sneak into processed foods.
Can You Ever Eat Dairy Again?
For some, gut healing allows for occasional dairy without issues. For others, dairy-free is the best long-term option to prevent inflammation and symptoms. Every case is different!
If you suspect dairy is making you feel bloated, fatigued, or inflamed, an elimination diet can give you answers. Test, eliminate, reintroduce, and listen to your body. Have you ever tried going dairy-free and noticed a difference?
References
Vojdani A. A potential link between food immune reactivity and neuroautoimmunity. J Neurol Neurophysiol. 2015;6(3):1-7.
Biesiekierski JR. Food intolerance in functional gastrointestinal disorders: a review. Nutrients. 2016;8(11):634.
Fasano A. Leaky gut and autoimmunity. Clin Rev Allergy Immunol. 2012;42(1):71-78.
Sicherer SH, Sampson HA. Food allergy: Epidemiology, pathogenesis, diagnosis, and treatment. J Allergy Clin Immunol. 2014;133(2):291-307.
