All About Dairy (Part1)
Lactose Intolerance & Dairy Sensitivities — Why Dairy Doesn’t Work for Everyone
For some people, a glass of milk is comforting, nostalgic, and nourishing. For others, it’s a fast track to bloating, gas, congestion, or skin breakouts. Dairy is one of the most controversial foods in modern nutrition — loved by some, dreaded by others.
But why is it that humans have consumed milk for thousands of years, yet today so many people struggle with it? Let’s dive into the difference between lactose intolerance, dairy allergies, and hidden dairy sensitivities — and why your body may or may not thrive on dairy.
Lactose Intolerance: The World’s Most Common Food Intolerance
Lactose is the natural sugar in milk. To digest it, the body makes an enzyme called lactase. Without enough lactase, lactose ferments in the gut — leading to bloating, gas, diarrhea, and discomfort.
Globally, about 65% of adults are lactose intolerant to some degree.
Rates vary: it’s most common in East Asian, West African, and Native American populations, and much less common in those of Northern European descent.
Many people lose lactase enzyme production after childhood, which is why dairy tolerance often decreases with age.
In other words: struggling with milk doesn’t mean something is “wrong” with you. For much of the world, it’s completely normal.
Dairy Allergy: A Different Beast
While lactose intolerance is about sugar, a dairy allergy is an immune reaction to the proteins in milk (casein or whey).
This can cause hives, swelling, or even life-threatening anaphylaxis.
Dairy allergy is more common in children, and many outgrow it.
It’s very different from lactose intolerance and requires strict avoidance.
Dairy Sensitivity: The Hidden Problem
Some people don’t test positive for lactose intolerance or allergy, but still react poorly to dairy. This is where dairy sensitivity comes in.
Symptoms can be delayed (hours to days later).
They may include: sinus congestion, chronic post-nasal drip, fatigue, brain fog, acne, eczema, migraines, joint pain, or digestive upset.
These sensitivities are often linked to leaky gut or immune overactivation.
This is why someone might tolerate cheese but not milk, or yogurt but not ice cream — the form and processing of dairy matter.
Gut Health Matters More Than We Think
One reason dairy issues seem more common today? Our guts aren’t as resilient as they once were.
Frequent antibiotic use, processed food diets, and environmental toxins have weakened our gut microbiomes.
A damaged gut lining makes it harder to handle casein or lactose.
For some, healing the gut first can improve dairy tolerance.
The Big Takeaway
Not all dairy problems are the same. Lactose intolerance is about sugar, dairy allergy is about the immune system, and dairy sensitivity is often about gut health and inflammation.
Understanding which one you’re dealing with is the first step in deciding whether dairy can be part of your diet — or whether it’s holding you back.
In the next post, we’ll explore why not all dairy is created equal — and how different types (raw, fermented, goat, sheep, skim vs. whole) affect the body differently.
References
National Institutes of Health. Lactose Intolerance and Health. [NIH Publication No. 13–7861].
Suchy FJ, Brannon PM, Carpenter TO, et al. NIH Consensus Statement on Lactose Intolerance and Health. NIH Consens State Sci Statements. 2010;27(2):1–27.
Heine RG, et al. Cow’s milk allergy in infancy and childhood. Expert Rev Clin Immunol. 2017;13(6):529-538.
Misselwitz B, et al. Lactose malabsorption and intolerance: pathogenesis, diagnosis and treatment. United European Gastroenterol J. 2013;1(3):151–159.