Are dairy and gluten really inflammatory? What the evidence actually says
Dairy and gluten are two of the most avoided food groups in the wellness space. Cutting them out has become almost a default recommendation online, often framed around the idea that both are inflammatory. It is a claim that sounds convincing, and for some people it sticks. But the evidence does not support blanket avoidance for most people. This post breaks down what dairy and gluten actually are, the specific conditions where avoidance is genuinely necessary, and why the type of food within each category often matters far more than the category itself.
Both dairy and gluten-containing foods have two key components: a protein component and a carbohydrate component. This distinction matters because reactions to these foods are almost never about the food as a whole. They are about a specific component, and which component is involved changes everything about how a reaction should be understood and managed.
Dairy contains proteins, primarily casein and whey, and a carbohydrate called lactose. The protein and carbohydrate content varies considerably across dairy products, with some being far richer in protein than others.
Gluten is itself a protein, made up of gliadin and glutenin, found in wheat, rye, and barley. Wheat also contains carbohydrates, including a group of fermentable fibres called fructans. These are structurally and functionally distinct from gluten, but are often mistakenly grouped with it when people report reactions to wheat-containing foods.
There are two conditions where dietary avoidance is medically necessary. Both are protein-based reactions. Both involve a genuine immune response. And both require proper clinical diagnosis and management.
Coeliac disease is an autoimmune condition in which the immune system reacts to gliadin, the protein component of gluten. This triggers an inflammatory response in the small intestine that damages the intestinal lining and impairs nutrient absorption. Strict, lifelong gluten avoidance is the only current treatment. This is a serious diagnosis requiring ongoing medical oversight and dietitian support.
Milk protein allergy involves an immune reaction to casein or whey, the protein components of dairy. It can present as an immediate IgE-mediated response or a delayed non-IgE response. It is most common in infants and young children and requires dairy protein avoidance under the guidance of a healthcare team.
Both of these are distinct clinical diagnoses. They are not a reason for the general population to avoid dairy or gluten.
Beyond allergies and autoimmune conditions, some people experience gut symptoms with dairy or wheat-containing foods. These reactions are real and can be significant, but they are mechanistically very different from coeliac disease or milk protein allergy. Importantly, they do not cause inflammation or damage to the gut.
Lactose intolerance occurs when the body produces insufficient lactase, the enzyme needed to digest lactose, which is the carbohydrate in dairy. Undigested lactose ferments in the large intestine, producing gas and causing bloating, cramping, and diarrhoea in some people. This is a digestive intolerance. There is no immune response and no damage to the gut lining. It is the carbohydrate component of dairy, not the protein, and it is not an inflammatory condition.
Fructan sensitivity is another frequently misunderstood issue. Fructans are fermentable carbohydrates found in wheat, as well as in onion, garlic, and several other foods. In people with a sensitive gut, particularly those with IBS, fructans can cause significant bloating, abdominal pain, and altered bowel habits. A landmark study found that in people who believed themselves to be gluten sensitive, it was actually fructans, not gluten protein, driving their symptoms.1 Again, this is a digestive intolerance involving the carbohydrate component of wheat. It is not inflammation, and it is not intestinal damage.
The distinction matters. An intolerance causes gut discomfort. An autoimmune condition like coeliac disease causes immune-mediated intestinal damage. They require very different responses.
For someone with IBS, identifying and reducing fructan-containing foods may genuinely help manage symptoms. But that is a targeted, evidence-based approach to gut symptom management. It is not the same as avoiding gluten for inflammatory reasons, and it is worth getting proper support to understand what is actually going on.
If you are experiencing gut symptoms with dairy or gluten-containing foods, those symptoms are real and worth taking seriously. Working with a dietitian can help to work out what is actually driving them, whether that is lactose, fructans, a protein-based reaction, or something else entirely, so that any changes you make are targeted and evidence-informed rather than a blanket elimination.
Like all things in nutrition, the nuance here matters. Dairy is not a single food. There is a wide spectrum of dairy products, and the type included makes a meaningful difference to what it contributes nutritionally.
Higher protein, higher nutrient options include Greek yoghurt, milk, kefir, cottage cheese, and hard cheese. These are rich in protein and calcium, and the protein content in particular can help support blood sugar balance, which in turn supports the body's inflammatory response. Greek yoghurt and kefir also contains live cultures that support gut microbiome health. These foods offer meaningful nutritional value and sit well within a balanced dietary pattern.2
At the other end of the spectrum, butter, cream, and ice cream are higher in saturated fat and provide little to no protein or calcium. They are not nutritionally equivalent to milk or yoghurt. That being said, all foods can be part of a balanced diet, and it is what we are having most of the time that matters most.
The research on dairy and inflammation is also worth noting. Systematic reviews of clinical evidence have not found dairy to be pro-inflammatory in healthy adults. Fermented dairy in particular is associated with beneficial effects on gut microbiome composition.2 The type of dairy, and the overall pattern it sits within, matters far more than dairy as a category.
The same principle applies to gluten-containing foods. Wholegrains sit at one end of a broad spectrum, and highly refined, ultra-processed grain products sit at the other. The gluten content may be similar, but the nutritional picture is very different.
Barley is one of the standout wholegrain options. It is one of the richest dietary sources of beta-glucan, a soluble fibre with strong evidence for supporting cholesterol reduction, blood glucose regulation, and gut microbiome health.3 Wholemeal bread, rolled oats, rye, spelt, farro, and freekeh also offer meaningful fibre, B vitamins, iron, and a broad range of micronutrients that refined alternatives simply do not provide.
Authentic sourdough is worth mentioning specifically. Made through traditional long fermentation, the process partially breaks down fructans, which can make sourdough better tolerated by people with fructan sensitivity. It also produces a lower glycaemic response compared to conventional bread, and provides a more complex nutrient profile.
White bread, pastries, and highly processed grain products at the other end of the spectrum offer far less in terms of fibre, B vitamins, and micronutrients. Wholegrains, as a food category, are associated with reduced risk of cardiovascular disease, type 2 diabetes, and colorectal cancer.3 Refined grain products do not carry that same evidence base. Again, all foods can fit within a balanced diet. The overall pattern and what we are eating most of the time is where the meaningful impact lies.
Interestingly, both dairy and gluten-containing foods form part of the Mediterranean dietary pattern, one of the most robustly researched dietary approaches in nutritional science. The Mediterranean diet includes dairy, particularly yoghurt and cheese, as well as wholegrains, legumes, vegetables, fruit, olive oil, and fish. It is not dairy-free or grain-free.
The evidence base for the Mediterranean diet is substantial. It is associated with:4
Reduced cardiovascular disease risk. The PREDIMED trial demonstrated a significant reduction in major cardiovascular events in those following a Mediterranean diet supplemented with extra-virgin olive oil or nuts.
Lower levels of inflammatory markers. The overall pattern of polyphenols, fibre, healthy fats, and antioxidants works collectively to support an anti-inflammatory environment in the body.
Improved gut microbiome diversity. The fibre and polyphenol content of a Mediterranean-style diet supports a diverse and healthy gut microbiome, which has downstream effects on immunity, mood, and metabolic health.
Reduced risk of type 2 diabetes and all-cause mortality. Multiple large studies and meta-analyses support the protective effect of this dietary pattern across multiple health outcomes.
Dairy and wholegrains are part of what makes the Mediterranean diet work. Removing them does not make the pattern healthier. What matters is which types of these foods are included and how they sit within the overall dietary pattern.
The conversation around dairy and gluten is worth having with nuance. For most people, the question is not whether to include these foods, but which versions to lean toward and how they fit within a broader eating pattern.
For those wanting to reduce or avoid dairy or gluten for personal preference, a dietitian can help to identify any common nutritional gaps that may arise, particularly around calcium and fibre, and support you in meeting those needs through other foods.
Want to know what works for you specifically?
Navigating dairy, gluten, gut symptoms, and the noise around elimination diets is much easier with personalised support. Nula Nutrition provides evidence-based registered dietitian consultations for women's health in Calgary and online across Alberta, including Canmore, Banff, Edmonton, and Cochrane.
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Book a Free Discovery CallWritten by Madison Hows RD APD
References
1. Skodje GI, et al. Fructan, rather than gluten, induces symptoms in patients with self-reported non-celiac gluten sensitivity. Gastroenterology. 2018;154(3):529–539. PMID: 29102613
2. Wastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184(16):4137–4153. PMID: 34256014
3. Reynolds A, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019;393(10170):434–445. PMID: 30638909
4. Estruch R, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts. New England Journal of Medicine. 2018;378:e34. PMID: 29897866
