Does milk cause inflammation in the body? The definitive scientific answer

December 18, 2025 •

5 min read

Contrary to popular belief, extensive reviews of randomized clinical trials indicate that for most people, dairy products do not cause inflammation, and some may even have anti-inflammatory effects. So, does milk cause inflammation in the body? The answer is more nuanced than a simple yes or no.

Quick Summary

Research suggests milk is not inherently inflammatory for most individuals. However, milk allergies or sensitivities to specific proteins, like A1 beta-casein, can trigger an inflammatory immune response in a subset of the population.

Key Points

Scientific Consensus: Multiple systematic reviews suggest that milk is not inherently inflammatory for the general population.
Fermented Dairy: Products like yogurt and kefir often have anti-inflammatory properties due to probiotics and other bioactive compounds.
A1 Protein Sensitivity: Some individuals may experience inflammation from the A1 beta-casein protein found in conventional milk, but tolerate A2 milk well.
Allergy vs. Intolerance: A milk protein allergy is an inflammatory immune response, while lactose intolerance is a non-inflammatory digestive issue.
Processing Matters: Added sugars and other additives in processed dairy products are more likely to cause inflammation than the dairy itself.
Individual Response: The effect of milk is highly personal; an elimination diet under professional supervision can help determine individual sensitivities.

The Evidence for a Neutral to Anti-Inflammatory Effect

For most of the healthy population, a large body of evidence from clinical trials indicates that milk and dairy products are either neutral or have a mild anti-inflammatory effect. Multiple systematic reviews, which analyze the results of several studies, have reached this conclusion. One such review published in the Journal of the American College of Nutrition evaluated 27 randomized controlled trials and found that dairy foods and proteins had neutral to beneficial effects on markers of inflammation. Some studies even show a reduction in inflammatory biomarkers following dairy consumption.

The Role of Fermented Dairy

Fermented dairy products, such as yogurt and kefir, are particularly beneficial due to their probiotic content. These beneficial bacteria help support a healthy gut microbiome, which is crucial for regulating the immune system and reducing overall inflammation. The fermentation process itself creates bioactive peptides and short-chain fatty acids that may also contribute to this anti-inflammatory effect.

The Nutrient Matrix

Dairy products are a rich source of essential nutrients that support overall health. Many are fortified with Vitamin D, which has anti-inflammatory properties, and they also contain beneficial compounds like Conjugated Linoleic Acid (CLA) and various vitamins and minerals that aid in immune function. This comprehensive 'nutrient matrix' is likely responsible for the beneficial or neutral effects observed in research, outweighing any potential pro-inflammatory factors for most people.

When Milk Can Cause an Inflammatory Response

While dairy is not an inflammatory trigger for everyone, certain individual conditions can lead to an adverse reaction that presents as inflammation. It is crucial to distinguish between a true allergy and an intolerance.

Milk Protein Allergy

An actual milk allergy involves an immune system overreaction to one of the proteins in milk, typically casein or whey. This triggers a full-blown inflammatory immune response, which can cause immediate symptoms ranging from mild (hives, skin rashes, congestion) to severe and life-threatening (anaphylaxis). Individuals with a confirmed milk allergy must avoid all dairy products.

A1 vs. A2 Beta-Casein Sensitivity

Another factor influencing milk's effect on inflammation is the specific type of beta-casein protein. Conventional milk from most Western dairy herds contains a mix of A1 and A2 beta-casein proteins. Research suggests that when the A1 protein is digested, it can break down into a peptide called beta-casomorphin-7 (BCM-7). For some sensitive individuals, BCM-7 has been linked to increased gastrointestinal inflammation, slower gut transit, and other discomforts. Milk containing only A2 beta-casein (found in some cows and most goats and sheep) does not produce BCM-7 and is often better tolerated by those who experience discomfort with regular milk.

The Role of Lactose Intolerance and Other Factors

Lactose intolerance is often confused with a milk allergy, but it is a separate issue that does not involve the immune system. It is a digestive problem resulting from a lack of the lactase enzyme needed to break down lactose, the sugar in milk. Symptoms like bloating, gas, and abdominal pain are caused by undigested lactose and are not an inflammatory immune response. However, some intestinal conditions involving existing inflammation can lead to temporary (secondary) lactose intolerance.

It is also important to consider the quality of dairy consumed. Highly processed dairy products, like sweetened yogurts or flavored milks, contain added sugars and artificial ingredients that can promote inflammation. The issue in these cases is not the dairy itself but the unhealthy additives.

Making Sense of Dairy and Inflammation for You

For most, incorporating milk and other dairy products into a balanced diet is perfectly healthy and not inflammatory. For those who experience discomfort, pinpointing the specific cause is key. An elimination diet, guided by a healthcare professional, can help determine if it's a protein allergy, A1 sensitivity, or just lactose intolerance. For many, simply switching to lactose-free or A2 milk, or focusing on fermented products, can resolve any issues.

Comparison of Milk Types and Inflammatory Potential


Feature	Conventional Milk (A1/A2)	A2 Milk	Lactose-Free Milk	Plant-Based Milks
Beta-Casein Protein	Contains both A1 and A2 protein	Contains only A2 protein	Contains both A1 and A2 protein	N/A (protein varies)
Lactose Content	Present	Present	Lactose removed	N/A (varies)
Inflammatory Potential	Neutral for most; potential trigger for A1-sensitive individuals	Lower potential for A1-sensitive individuals	Neutral for most; avoids lactose intolerance symptoms	Varies; some fortified varieties have anti-inflammatory nutrients
Best For	General population without sensitivities	A1-sensitive individuals with or without lactose intolerance	Individuals with lactose intolerance but not A1 sensitivity	Dairy-free diets, vegans, those with allergies

A List of Anti-Inflammatory Foods

To support a healthy, anti-inflammatory lifestyle, consider incorporating these foods into your diet:

Leafy Greens: Spinach, kale, and broccoli are rich in anti-inflammatory vitamins.
Fatty Fish: Salmon, tuna, and mackerel are great sources of anti-inflammatory Omega-3s.
Fruits and Berries: Cherries, blueberries, and citrus fruits are packed with antioxidants.
Nuts and Seeds: Almonds, walnuts, and chia seeds offer healthy fats and fiber.
Fermented Foods: Yogurt, kefir, and kimchi provide probiotics for gut health.
Herbs and Spices: Turmeric, ginger, and garlic have potent anti-inflammatory properties.
Extra Virgin Olive Oil: A staple of the Mediterranean diet, rich in healthy fats and antioxidants.

Conclusion

The notion that milk universally causes inflammation is not supported by current scientific evidence for the majority of people. A person's reaction to dairy is highly individual and depends on several factors, including genetic sensitivities to specific proteins, existing allergies, or issues with lactose digestion. For those without an underlying condition, milk and other dairy products can be a nutritious part of an overall anti-inflammatory diet. If you suspect dairy is causing you problems, the first step is to consult a healthcare provider or a registered dietitian to identify the specific issue before eliminating a nutrient-rich food group completely. Understanding the difference between a real immune response and simple digestive discomfort is key to making informed dietary choices that support your health.

For more information on the A1/A2 beta-casein difference and its effects, you can read research available from the NIH, such as Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein on gastrointestinal physiology, symptoms of milk intolerance, and markers of inflammation in Chinese adults: a double-blind randomized cross-over trial.

Frequently Asked Questions

For most healthy individuals, dairy is neither good nor bad for inflammation, as it appears to have a neutral to beneficial effect. However, for those with a dairy allergy or sensitivity, it can be a pro-inflammatory trigger.

A milk allergy is an immune system-mediated inflammatory response to milk proteins (casein and whey). Lactose intolerance is a digestive issue, not an inflammatory one, caused by the inability to digest milk sugar (lactose).

Some research suggests that individuals sensitive to the A1 beta-casein protein in conventional milk may experience less gastrointestinal inflammation and discomfort by switching to milk containing only the A2 protein.

Highly processed dairy products with added sugars and artificial ingredients are more likely to contribute to inflammation than whole, minimally processed dairy. For example, a sugary ice cream is less beneficial than plain yogurt.

To reduce inflammation, focus on a diet rich in fruits, vegetables, nuts, seeds, fatty fish (like salmon), and fermented foods (yogurt, kefir). Spices like turmeric and ginger also have anti-inflammatory properties.

Signs of sensitivity can include gastrointestinal issues, skin irritations (like acne or eczema), or congestion after consuming dairy. The best way to test is an elimination diet under the guidance of a healthcare professional to reintroduce foods systematically.

The inflammatory potential of dairy alternatives depends on the product. Some, like hemp or coconut milk, may contain beneficial fats or nutrients. However, many commercial alternatives contain inflammatory ingredients like added sugar or refined oils, so reading labels is important.