Interest in eating a plant-based diet to help treat Crohn’s has become increasingly popular in the past few years, as research shows that foods high in sugar, animal fat, and animal protein may increase the risk of Crohn’s disease. Although there are few studies on the specific effect of veganism on Crohn’s disease, research points to the health benefits of a plant-based diet for preventing relapse in Crohn’s patients. Learn about the evidence surrounding plant-based diets and whether they are right for you.
What Does the Science Say?
When it comes to healthy eating for people with IBD, the best diet seems to be one that nourishes your gut bacteria. The gut microbiome contains trillions of microorganisms with multiple roles in the body — from helping with digestion to reducing inflammation. In a review published in 2019 in The Permanente Journal, animal-based diets were consistently associated with a lower diversity of gut bacteria and promotion of mucus-degrading bacteria that irritate the gut barrier and leads to IBD. Meanwhile, a plant-based diet was linked to an abundant richness of bacteria that reduce the risk of inflammation. Mitsuro Chiba, MD, PhD, chief of the inflammatory bowel disease section at Akita City Hospital in Japan and lead author on the study, points out that there are beneficial and harmful bacteria in the gut that can become unbalanced when eating a Westernized diet loaded with meat and sugar. Another review, published in February 2020 in Expert Review of Gastroenterology & Hepatology, found that Western diets form a gut microbiome with bacteria that produce less short-chain fatty acids — these are made after “good” gut bacteria ferment fiber in the colon and are involved in regulating immunity and reducing inflammation, per an article published in April 2021 in Cellular & Molecular Immunology. Conversely, plant-based diets high in fiber increased the production of short-chain fatty acids. Although there are few studies on the specific effect of veganism on Crohn’s disease, some research points to the health benefits of a plant-based diet for preventing relapse in Crohn’s patients. A case study published in June 2019 in Nutrients described a patient with Crohn’s disease who entered remission after switching to a plant-based diet rich in legumes, vegetables, and fruit. A separate case study, published in February 2019 in Advanced Research in Gastroenterology & Hepatology (PDF), reported “significant improvements in symptoms” of one patient with Crohn’s disease who went on a plant-based diet.
Should We Be Skeptical?
With its potential to restore healthy gut bacteria, a plant-based diet holds promise for patients with IBD. But more extensive studies and clinical trials are needed before recommending plant-based diets to all people living with Crohn’s. “Most information that presents as inflammatory or noninflammatory diets are based on personal experience, or anecdotal research that is not in-depth. And most of the research being done in-depth fails to show a specific form of a diet as anti-inflammatory, or end up aggravating the situation of Crohn’s and inflammation,” says Ashkan Farhadi, MD, a gastroenterologist at MemorialCare Orange Coast Medical Center in Fountain Valley, California. In fact, some plant-based foods may worsen your risk of Crohn’s disease. A study published in June 2021 in Current Developments in Nutrition found that unhealthy plant-based foods — refined grains, pastries, sweetened beverages, desserts — increased the risk of developing Crohn’s and ulcerative colitis later on in life. The different conclusions drawn by studies may further suggest the uniqueness of each Crohn’s case. As Kelly Kennedy, RD, resident nutritionist for Everyday Health, says, “The foods that affect people with Crohn’s disease vary from person to person and, in time, can even change for the same person.” What may benefit your body could trigger a flare-up for someone else, meaning that no one diet will be suitable for every individual.
How to Safely Incorporate More Plant-Based Foods in Your Diet
If you’re considering a plant-based diet, be that semi-vegetarian, vegetarian, or vegan, or simply just reducing your meat intake, here are some tips for eating mindfully and making the transition as smooth and simple as possible:
Go Slow and Give Yourself Time
Whenever you make significant dietary changes, it’s always smart to make them slowly so your body has time to adjust to a new way of eating. With this in mind, be kind to yourself when you change your eating habits and don’t beat yourself up when you make mistakes. Everyone’s Crohn’s case is unique and some people might be more tolerant to certain foods than others. Try keeping a food journal to record your meals and your symptoms, so you can track which foods your body tolerates better than others.
Remember to Stay Hydrated
As you make the switch to a plant-based diet, remember to keep drinking plenty of fluids. Your body is 60 percent water, meaning dehydration can cause serious issues with your bodily functions. The Crohn’s & Colitis UK says the risk of dehydration is greater for people with IBD, and dehydration may aggravate IBD symptoms. Drinking fluids such as water, broth, or tomato juice, which has a very high water content, until your urine is clear or light yellow is a good indication that you’re well-hydrated. However, the Crohn’s & Colitis Foundation advises to limit your intake of ice-cold water and coffee. While neither of the beverages promote inflammation, ice-cold water can cause cramps and caffeinated drinks can increase the risk of diarrhea. Sweetened beverages and alcohol should also be avoided.
Get Enough Protein
Since meat is such a rich source of protein, you may be concerned about where to get your protein when you cut that food group out of your diet. Eggs, fish, milk, yogurt, nut butters, legumes, and cottage cheese are all great sources of protein. There’s also a variety of foods made with protein-rich soy that mimic meats like chicken and ground beef. Remember to ease into it and go with what your digestive tract can tolerate.
Keep an Eye on Your Iron Levels
Iron deficiency is fairly common for those with Crohn’s, and cutting iron-rich meat out of your diet further increases that risk. To avoid this, eat foods that contain high amounts of iron, like leafy green vegetables (as long as they’re tolerable), potatoes, and even dark chocolate. You can also look to foods fortified with iron, such as breakfast cereals and tofu. The body has more trouble absorbing these types of iron than the one found in meats, so to increase absorption Kennedy recommends a source of vitamin C, such as orange juice, at the same meal.
Ease the Impact of High Fiber Foods
Plant-based diets tend to be high in fiber, which can be difficult for someone with Crohn’s who’s trying to avoid high-fiber foods that can aggravate the bowels. To ease the impact of high-fiber foods, try choosing white bread and pasta over the whole grain versions, and peeling and cooking vegetables instead of eating them raw. “You can also opt for nutritious and naturally low-fiber foods, such as eggs, dairy, and nut butters, as long as they’re well-tolerated,” Kennedy says.
Think About Vitamin Supplements
Crohn’s disease often limits the amount of vitamins and minerals your body can absorb from foods. People with Crohn’s disease have low levels of Vitamin B12 and Vitamin D, and Kennedy says this can be further depleted for those following a semi-vegetarian, vegetarian, or vegan diet. Because meat, poultry, and fish are three main sources of these vitamins, you may need to take supplements to maintain vitamin levels. If you’re transitioning to a plant-based diet, be aware of this deficiency and talk to your doctor about supplementing. The Crohn’s & Colitis Foundation says that some vitamin supplements have sugar alcohols and preservatives that increase the risk for a flare-up. Also, some supplements and medications may have gastrointestinal side effects such as nausea and diarrhea.
Talk to Your Doctor
Remember to consult your doctor or a registered dietitian before making changes to your diet. Choosing the most nutritious foods possible to maximize calories, protein, vitamins, and minerals is particularly important for those with Crohn’s disease, and a professional healthcare provider can help with that. Additional reporting by Jocelyn Solis-Moreira.
