Going gluten-free is a journey. Some people notice immediate improvement in health once they stop eating gluten; others need more time before they feel fully recovered. However, even after eliminating gluten, some people continue to experience digestive symptoms. In many cases, removing dairy as well can lead to further relief.
If you follow a gluten-free diet but still have ongoing gastrointestinal issues, consider reducing or eliminating dairy. Lactose intolerance is a common cause, but other components of milk—such as the proteins casein and whey—can also trigger symptoms or allergic reactions in susceptible individuals.
Lactose Intolerance
For people with celiac disease, removing dairy is often necessary. Damage to the small intestine can reduce or eliminate production of lactase, the enzyme that breaks down lactose (the sugar in milk). When lactose cannot be digested, it can cause bloating, gas, diarrhea, cramps and general discomfort. Many people with long-term undiagnosed celiac disease develop secondary lactose intolerance because the small intestine was injured before the gluten-free diet began.
Lactose intolerance is also common in the general population. A substantial portion of adults produce less lactase as they age, and certain ethnic groups experience lactose intolerance at much higher rates. Lactose is present in all mammalian milk products—cow, goat, sheep and human milk—and is therefore found in butter, cream, cheese, cottage cheese, yogurt and ice cream. Lactose can also appear as an ingredient or filler in many processed foods and some medications, so reading labels carefully is important for anyone avoiding lactose.
Some dairy products naturally contain less lactose: many hard cheeses and fermented yogurts have reduced lactose levels due to the production process. Lactose-free milk, which has lactase added, is increasingly common, and new lactose-free cheeses and dairy alternatives continue to expand choices for those who need them.
Casein & Whey
Not everyone reacts to milk because of lactose. Some people are sensitive or allergic to milk proteins—chiefly casein and whey. Casein is the curd that forms when milk sours, while whey is the liquid left behind. Allergies can involve one or both proteins, and it is sometimes challenging to identify which protein is responsible, since many product labels simply list “milk” rather than identifying specific milk proteins.
Whey is common in protein powders and supplements because it is a fast-absorbing protein that can support muscle building and satiety. Casein may be used in ice creams, flavored products, processed foods, some cheeses and in certain non-dairy appearing items. Products labeled Kosher pareve are typically casein-free, which can help people avoiding that specific protein.
Milk Protein Allergy
When a true milk protein allergy is present, the safest approach is to avoid all milk-derived products. Reactions can range from gastrointestinal distress to systemic allergic symptoms, so accurate diagnosis and strict avoidance are essential for health and safety. If you suspect a milk protein allergy, consult an allergist or your healthcare provider to confirm the diagnosis and get personalized guidance.
Note: If gastrointestinal symptoms persist even after eliminating gluten and dairy, some people find relief by removing additional cross-reactive foods or other triggers. Working with a knowledgeable clinician, registered dietitian, or allergist can help identify other food sensitivities, nutrient gaps and dietary strategies that support recovery.
For those choosing to avoid dairy, many alternatives and dairy-free products are available today. Plant-based milks, yogurts, cheeses and butter substitutes allow people to maintain familiar flavors and textures while avoiding lactose and milk proteins. In cooking and baking, common dairy replacements include non-dairy milks (almond, soy, oat, rice, coconut), vegan butter or oil, and specialized dairy-free cheeses and creams designed for baking and cooking.
When making the transition away from dairy, pay attention to nutrition. Milk and dairy are common sources of calcium, vitamin D and protein in many diets. Replace these nutrients through fortified non-dairy milks, leafy greens, legumes, nuts, seeds, and, if needed, supplements recommended by your healthcare provider.
Eliminating dairy alongside gluten can make a meaningful difference in how you feel. With careful label reading, smart substitutions and guidance from health professionals when necessary, most people can find satisfying and nutritious dairy-free options that support better digestion and overall well-being.