Since inflammatory bowel disease (IBD) affects the digestive tract, what you eat or don’t eat can minimize symptoms. With so much interest surrounding nutrition and IBD, there's also a considerable amount of misinformation and perpetuation of nutrition myths, both online and even among well-meaning healthcare professionals. This misinformation often encourages unnecessary dietary restrictions, which may contribute to nutrient deficiencies and significantly impact quality of life in those with IBD.
As someone living with ulcerative colitis (UC) for over 20 years, and a registered dietitian specializing in gastrointestinal health, I work to dispel false information and clear up confusion. Here are five of the most common myths I hear surrounding nutrition and IBD, debunked.
1. Those With IBD Should Follow a Low-Fiber Diet
Avoiding fibrous foods during flares can reduce gastrointestinal (GI) symptoms, but this doesn’t mean you should write off fiber entirely. Some people with IBD do in fact eliminate fiber from their diets. Research published in the Journal of the Academy of Nutrition and Dietetics in April 2021 demonstrated that those with IBD often consume significantly less fiber than those without IBD. Frequently, the messaging individuals with IBD receive surrounding fiber is not up-to-date with current research, and often provokes fear of fiber-rich foods. Historically, those experiencing active IBD flares were routinely prescribed low-fiber diets. This recommendation was based on patients reporting fewer symptoms after reducing their fiber intake rather than on actual scientific evidence, as outlined in research published in the Lancet Gastroenterology and Hepatology in May 2019. Further, the importance of eventually reincorporating high-fiber foods back into the diet was rarely emphasized.
In recent years, these low-fiber dietary recommendations have been debunked, and the focus has been shifted from limiting grams of fiber, to modifying the texture of foods to eliminate roughage, the indigestible parts of vegetables, instead.
Cooking methods like steaming, and preparation methods like blending, mashing, and pureeing help to “pre-digest” fibers in fruits and vegetables, minimizing mechanical irritation to the gut lining, while still feeding your good gut microbes during flares.
2. Everyone With IBD Should Avoid Gluten
People with IBD are often advised to avoid gluten, but this isn’t always necessary. While there is limited data suggesting that a gluten-free diet may improve IBD symptoms for some, this data largely comes from observational studies that cannot prove causation, according to research published in the journal Molecular Nutrition & Food Research in June 2020. It goes without saying that those with celiac disease or non-celiac gluten sensitivity should avoid gluten, but not everyone with IBD has these conditions.
Many heavily processed foods happen to contain gluten, so if your symptoms improve on a gluten-free diet, cutting back on processed foods may be the reason for your symptom improvements, rather than the gluten itself. Further, gluten-containing grains also contain fructans, a FODMAP, or type of carbohydrate that is highly fermentable by gut bacteria. Generally this fermentation is a good thing, as we want to feed these bacteria, but as a by-product of fermentation, gases are produced. These gases may contribute to functional GI symptoms like bloating, abdominal cramping, and bowel irregularities in those who have irritable bowel syndrome (IBS) in addition to their IBD. Fortunately, if a fructan intolerance is to blame for your symptoms rather than gluten, you can still eat slow-fermented sourdough breads made from wheat flour. The fermentation process breaks down fructans found in wheat, so your gut bacteria don’t have to.
It is important to note that those with IBD are already at an increased risk for nutrient deficiencies and malnutrition, so restricting gluten from your diet without a clear indication to do so may contribute to this risk. Many gluten-containing whole grains like barley and rye are rich in B vitamins, and contain prebiotic fiber to support a healthy gut microbiome. If you suspect that you may have a gluten sensitivity, it’s helpful to work with a GI-specialized registered dietitian to evaluate whether or not a gluten-free diet is appropriate.
3. Everyone With IBD Should Avoid Dairy
Some individuals with IBD find that dairy worsens their GI symptoms, but this is not always due to dairy itself. Certain dairy products like cheese, ice cream, and butter are high in saturated fat, which can negatively impact the gut microbiome and promote inflammation, according to a review published in the journal Nutrients in February 2022. When eaten in larger portions, full-fat dairy products can also be difficult to break down, contributing to bloating and other GI symptoms. Additionally, the lactose found in dairy products is problematic for those with lactose intolerance. That said, if you are lactose intolerant, you don’t necessarily have to cut dairy products out of your diet entirely. Many dairy products are surprisingly low in lactose, like aged cheeses and kefir. Lactose-free versions of dairy products like milk and yogurt are also available at many grocery stores, as well as lactase pills, the enzyme that breaks down lactose.
Research published in the journal Arquivos de Gastroenterologia in September 2022 found that those with IBD who do not have a family history of lactose intolerance seem to have rates of dairy intolerance similar to the general population. As a result, the study authors concluded that in the absence of a clear intolerance, those with IBD need not avoid dairy.
Certain dairy products, like yogurt and kefir are not only generally well-tolerated by those with IBD, they also can provide many health benefits. These foods are an excellent source of calcium to support bone health, and are high in protein, helping you meet your needs. Since yogurt and kefir are fermented foods, they also help to populate the gut with probiotic bacteria.
4. Diet Has No Impact on IBD
Diet cannot necessarily cure IBD, but it is well-established that diet can aid in symptom management and even influence disease course, as outlined in research published in the journal Nutrients in December 2020. According to the aforementioned research, what we eat influences both IBD risk and activity, likely by impacting the gut microbiome, affecting the health and integrity of the gut lining, and interacting with our immune system, influencing the body’s immune response.
No one diet will work for everyone with IBD, as each individual has unique needs and symptom triggers, but this does not mean that diet is unimportant. Keep in mind that your dietary needs and tolerance to different foods can change over time depending on many factors, such as whether you are in a flare or remission, medication changes, surgeries, changes in the location or severity of inflammation, and nutrient deficiencies that may arise. Working with an IBD-specialized registered dietitian can guide you to find the best dietary approach for your specific needs.
5. IBD Is Caused by a Poor Diet
After receiving an IBD diagnosis, many wonder if there is something they may have done to cause the condition, like eating too much junk food or not enough fruits and vegetables. But just as diet cannot cure IBD, those with IBD did not give themselves the condition simply by eating poorly. While certain dietary pattens are associated with increased risk for IBD, diet is not the only factor at play. The cause of IBD is thought to be multifactorial, involving a combination of genetic and environmental factors, according to the Crohn’s and Colitis Foundation (CCFA). For example, the prevalence of IBD is greater in developed countries, urban environments, northern climates, and among those who have a first-degree relative with IBD. Additionally, factors like smoking, use of antibiotics and nonsteroidal anti-inflammatory drugs, and history of an appendectomy are all factors that have been associated with increased risk of IBD, per the CCFA. Diet is simply a piece of the puzzle, but not the full picture when it comes to IBD risk.