The relationship between diet and inflammatory bowel disease (IBD) is increasingly clear: dietary patterns can significantly influence both the risk of developing IBD and the frequency of flare-ups in those already diagnosed. Emerging research highlights the detrimental effects of certain foods, particularly ultra-processed options, while emphasizing the protective benefits of a diet rich in whole foods, especially those found in a Mediterranean-style eating plan.
Dietary Patterns and IBD Risk
Epidemiological surveys indicate a correlation between higher consumption of foods rich in animal fats and omega-6 fatty acids – such as red meats – refined sugars, fast food, and sugary drinks, and an increased risk of IBD. Conversely, diets abundant in fish, omega-3 fatty acids, fruits, and vegetables appear to be protective. This suggests that the composition of one’s diet plays a crucial role in modulating the inflammatory processes central to IBD.
The impact of diet extends to family members of IBD patients. A study known as The GEM project, conducted in 2022, found that children with a first-degree relative diagnosed with IBD who followed a Mediterranean-type diet experienced modifications to their gut microbiota, resulting in a less pro-inflammatory profile. This suggests that dietary interventions can influence the gut microbiome even before the onset of disease.
The Impact of Ultra-Processed Foods
Perhaps the most striking finding in recent research concerns ultra-processed foods. Data indicates that even a modest increase in their consumption can dramatically elevate the risk of developing IBD. Specifically, a 5% increase in ultra-processed food intake – compared to a diet with none – is associated with a staggering 450% increase in IBD risk. This figure has been consistently confirmed in meta-analyses, solidifying the link between these foods and disease development.
In France, where ultra-processed foods represent approximately 30% of the average diet, the implications are significant. Reducing consumption of these foods is now being explored as a preventative strategy.
Dietary Fiber and Crohn’s Disease
Specific dietary components are also under investigation for their role in managing IBD. Consumption of inulin and beta-glucan, types of dietary fiber, has been associated with a reduction in Crohn’s disease flares, as observed during the United European Gastroenterology Week conference in 2025 in Berlin.
Dietary Interventions During Flare-Ups
When IBD is already active, dietary modifications can also play a therapeutic role. During severe Crohn’s disease flare-ups in children, enteral nutrition (receiving nutrition through a tube) has been shown to support growth and achieve better results than corticosteroids in healing the intestinal mucosa.
The Crohn’s Disease Exclusion Diet (CDED) has also been rigorously studied. A prospective randomized study compared CDED to corticosteroid therapy in both children and adults experiencing moderate flare-ups. The CDED involves a phased approach, initially restricting intake to a limited range of foods – primarily white rice and certain fruits and vegetables – supplemented with 50% enteral nutrition. Over six weeks, the diet gradually expands to include foods like tuna, lean meat, sweet potatoes, wholemeal bread, and quinoa, while reducing the enteral nutrition component to 25%. Results from this study favored the CDED, demonstrating better tolerance and faster mucosal healing.
The “Tasty & Healthy” Diet and Emulsifiers
Researchers are also exploring simplified dietary approaches. The “tasty & healthy” diet prohibits all processed and packaged foods, animal fats (except natural yogurt), fried foods, gluten, salt, sugar (allowing honey in small amounts), and alcohol, while permitting all other foods. Recent findings suggest this diet is as effective as exclusive enteral nutrition in managing moderate to severe flare-ups and is better tolerated by patients.
A particularly intriguing area of research focuses on the role of emulsifiers – additives commonly found in processed foods. The Addapt study, currently being published, involved 154 patients with Crohn’s disease in flare-ups. Participants were trained to identify foods without emulsifiers and then received, for eight weeks, 25% of their food via delivery, either containing zero emulsifiers or containing emulsifiers. The results showed a statistically significant benefit to the low-emulsifier diet, with 49% achieving clinical remission compared to 31% in the emulsifier group. The low-emulsifier diet led to a greater reduction in fecal calprotectin levels – a marker of intestinal inflammation.
The Mediterranean Diet for Prevention and Remission
The question of whether reducing ultra-processed food intake translates to fewer IBD flare-ups is being actively investigated. Data suggests that patients consuming less than four servings of ultra-processed foods per day experience fewer flare-ups. The Mikinautes cohort study, involving 650 patients with IBD in remission, demonstrated that those with diets rich in fruits, vegetables, nuts, whole grains, and eggs had a 50% lower risk of relapse within two years compared to those with lower consumption of these foods.
Given these findings, learned societies are increasingly recommending a Mediterranean-type diet for individuals with IBD, both for prevention and for maintaining remission. Professor Xavier Hébuterne, a gastroenterologist, emphasizes the importance of patient support, particularly from dietitians, in implementing these dietary changes. While enteral nutrition remains a valuable tool, especially in children, adolescents, and malnourished patients, a healthier, less processed diet is now recognized as a cornerstone of IBD management.
