A new research review suggests that eating a diet high in ultra-processed foods may increase the risk of developing Crohn’s disease. The review, published in the journal Nutrients, analyzed over a decade of research on the topic.
Researchers looked at population data, laboratory experiments, and dietary studies to see if a pattern emerged. They found that people who consumed more ultra-processed foods had a higher risk of developing Crohn’s disease. This link was much weaker for ulcerative colitis, another form of inflammatory bowel disease (IBD).
Nearly five million people worldwide now live with IBD. Rates are rising fastest in countries where ultra-processed foods are common in the diet. Genetics alone cannot explain this increase, leading researchers to examine environmental factors like diet.
The review focused on the structure of the food itself, not just calories, fat, or carbohydrates. Ultra-processed foods are industrial formulations made with refined ingredients and additives such as emulsifiers, artificial sweeteners, thickeners, and colorants.
Laboratory studies offer clues about why these foods may harm the gut. Some emulsifiers appear to thin the protective mucus layer in the gut. This makes it easier for bacteria to come into direct contact with intestinal tissue. Other additives can change the gut microbiome, reducing beneficial bacteria and encouraging inflammatory ones.
Some additives may also increase intestinal permeability, often called “leaky gut.” This allows bacterial fragments to cross into the bloodstream and activate immune responses. Over time, this low-grade immune activation may contribute to the chronic inflammation seen in Crohn’s disease.
The research does not prove that ultra-processed foods directly cause Crohn’s disease. Most of the evidence is observational. However, the combination of population data, biological mechanisms, and clinical outcomes makes the link hard to ignore.
For people already living with IBD, higher intake of ultra-processed foods has been linked to greater disease activity and a higher risk of relapse. On the other hand, diets that greatly reduce ultra-processed foods, such as the Crohn’s Disease Exclusion Diet, have helped induce remission, especially in children.
The same gut changes linked to Crohn’s disease, including microbiome disruption, barrier breakdown, and chronic inflammation, are also tied to other health problems. These include metabolic disease, immune dysfunction, and mental health conditions.
The review suggests that reducing ultra-processed foods in the diet may be a practical way to protect gut health. This does not mean avoiding all processed foods or aiming for a perfect diet. Convenience is sometimes necessary. But the research supports being more aware of how often these foods make up the bulk of a person’s diet.
Centering meals around whole or minimally processed foods when possible is one step. Paying attention to ingredient lists, especially long strings of additives, can also help. Building a small rotation of simple, repeatable meals at home is another strategy. For people with digestive symptoms, working with a practitioner who understands gut health may be useful.
