Dairy and IBD

Dairy is one of the most commonly restricted food groups in people with IBD. Many people restrict dairy due to what they’ve heard or read or their own personal experiences with it. This post looks at what the evidence says about the association between dairy and IBD and offers some alternative suggestions if dairy doesn’t sit well with you.

Is there an association between dairy consumption and risk of flare-ups?

Many of the popular diets out there for IBD, like the Specific Carbohydrate Diet and the IBD Anti-Inflammatory Diet, limit or restrict lactose and/or dairy products. However, these  diets also restrict a myriad of other things. Although some of these diets seem to help induce and/or prolong remission for some people, it is unclear which components of the diets are responsible for these effects. At this time, there is no strong evidence to suggest that dairy consumption increases the likelihood of flare-ups nor is there sufficient evidence to show that dairy consumption is protective against flare-ups.

Lactose intolerance and IBD

Lactose intolerance is defined as having lactose maldigestion (lactose not properly broken down by the enzyme lactase) and symptoms post lactose consumption, such as diarrhea, abdominal pain, bloating, and flatulence. It is possible to have lactose maldigestion without lactose intolerance. Alternatively, some people think they have lactose intolerance while tests show no evidence of lactose maldigestion. Lactose maldigestion is most commonly diagnosed through a breath test done at a lab. Lactose maldigestion is different from a milk protein allergy, where there is an immune system reaction to the protein in milk that can produces symptoms such as hives, wheezing, itching or tingling of the mouth, nose and throat. Around 70% of the world’s population has lactose maldigestion that begins after weaning and this is dependent on ethnicity and genetic makeup. This is called primary lactase deficiency. If lactose maldigestion develops later in life, it is called secondary lactase deficiency. The rates of lactose intolerance between people with and without IBD do not seem to differ significantly, with the exception of people with small bowel Crohn’s disease, who have a higher tendency to have lactose intolerance, as this is where the enzyme lactase is found. Flare-ups in small bowel Crohn’s disease may lead to worsening of lactose intolerance, but this is unproven.

Nutritional benefits of dairy

Dairy is a significant source of calcium and protein. Also, some dairy products, like milk, are fortified with vitamin D. Calcium and vitamin D are not only beneficial for bone health, but some studies suggest they help reduce inflammation and the risk for colorectal cancer. Some people may avoid dairy as they’re concerned it contains antibiotics and growth hormones. In Canada, it is illegal to use growth hormones in dairy cows. There are rigorous standards around antibiotic use in dairy cows and milk is tested to ensure it does not contain any antibiotics before it is sold to consumers for consumption.

Do you need calcium and vitamin D supplements?

Calcium and vitamin D needs vary depending on age, sex and the use of certain medications, such as Prednisone. It is recommended to take a food-first approach whenever possible. Calcium-rich foods include dairy, such as milk, cheese and yogurt, as well as some plant-based foods like almonds and leafy greens. Most plant-based milks are fortified with calcium, but this needs to be confirmed by checking the ingredients list. Calcium supplements are an option if you can’t get enough from your diet. Calcium carbonate is the most constipating but least expensive form. Calcium citrate may be better absorbed and have less side effects but is more expensive. Only a few foods contain vitamin D, such as fatty fish, eggs yolks, and fortified foods. It is usually recommended that people with IBD take a vitamin D supplement given that it is difficult to get enough from dietary sources. For more information on food sources of calcium and vitamin D, go to Healthlink BC.

Strategies to help with dairy tolerance

If you are sensitive to dairy products and you suspect that it’s related to lactose, there are different options to consider. Yogurt and cheese are lower in lactose than milk as the fermentation they undergo digests some of the lactose. Other potential strategies would be to have smaller portions of dairy spread out throughout the day and to consume dairy with a meal versus on its own. Some research suggests that lactose-intolerant individuals who consume lactose on a regular basis can cause their gut bacteria to adapt in dealing with undigested lactose. This may increase their tolerance to lactose over time. Lactase pills can be taken at the same time as consuming dairy products, but keep in mind that some contain sugar alcohols which may contribute to gas and bloating. Alternatively, there are many lactose-free dairy products available at grocery stores. If negative symptoms persist despite trying the above strategies, there may be other components in dairy you are sensitive to. Some individuals have uncomfortable symptoms after consuming large amounts of fat, so lower fat dairy options may be better tolerated. There are a few studies in humans showing that the casein in cow’s milk, A1, may lead to abdominal pain, bloating and loose stools in some people. Milk products from sheep, goat and water buffalo may be better tolerated as they contain a different type of casein, called A2. Many stores in Canada now sell A2 cow’s milk; these products will have A2 shown on the front of the milk carton. More research is needed in this area. More research is needed in this area.

Take-Away Points
  • There is insufficient evidence to say that dairy prevents or causes flare-ups.
  • Having Crohn’s disease that involves the small bowel may result in lactose intolerance.
  • A food-first approach for getting calcium is recommended but supplements are an option if needed.
  • If tolerance of dairy is an issue, there are many strategies that can help with digestion.


  1. Brooke-Taylor, S., Dwyer, K., Woodford, K., & Kost, N. (2017). Systematic Review of the Gastrointestinal Effects of A1 Compared with A2 β-Casein. Advances in Nutrition: An International Review Journal8(5), 739–748. doi: 10.3945/an.116.013953
  2. Eadala, P., Matthews, S. B., Waud, J. P., Green, J. T., & Campbell, A. K. (2011). Association of lactose sensitivity with inflammatory bowel disease – demonstrated by analysis of genetic polymorphism, breath gases and symptoms. Alimentary Pharmacology & Therapeutics34(7), 735–746. doi: 10.1111/j.1365-2036.2011.04799.x
  3. Ho, S., Woodford, K., Kukuljan, S., & Pal, S. (2014). Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study. European Journal of Clinical Nutrition68(9), 994–1000. doi: 10.1038/ejcn.2014.127
  4. Itan, Y., Jones, B. L., Ingram, C. J., Swallow, D. M., & Thomas, M. G. (2010). A worldwide correlation of lactase persistence phenotype and genotypes. BMC Evolutionary Biology10(1), 36. doi: 10.1186/1471-2148-10-36
  5. Jianqin, S., Leiming, X., Lu, X., Yelland, G. W., Ni, J., & Clarke, A. (2015). Erratum to: ‘Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows’ milk.’ Nutrition Journal15(1). doi: 10.1186/s12937-016-0164-y
  6. Kirschner, B. S., Defavaro, M. V., & Jensen, W. (1981). Lactose Malabsorption in Children and Adolescents with Inflammatory Bowel Disease. Gastroenterology81(5), 829–832. doi: 10.1016/s0016-5085(81)80104-7
  7. Spooren, C. E. G. M., Pierik, M. J., Zeegers, M. P., Feskens, E. J. M., Masclee, A. A. M., & Jonkers, D. M. A. E. (2013). Review article: the association of diet with onset and relapse in patients with inflammatory bowel disease. Alimentary Pharmacology & Therapeutics38(10), 1172–1187. doi: 10.1111/apt.12501
  8. Szilagyi, A., Galiatsatos, P., & Xue, X. (2016). Systematic review and meta-analysis of lactose digestion, its impact on intolerance and nutritional effects of dairy food restriction in inflammatory bowel diseases. Nutrition Journal15(1), 67. doi: 10.1186/s12937-016-0183-8


 Written by: Gina Almasan, RD