Inflammatory bowel disease (IBD) is a long-term condition that causes inflammation in the digestive system. The two main types of IBD are Crohn’s disease and ulcerative colitis. These conditions can lead to symptoms like stomach pain, diarrhea, fatigue, weight loss, and a reduced quality of life.
While scientists have made notable advances in understanding IBD, many questions still remain about why certain individuals develop the disease while others do not.
Recent interest has focused on diet as a possible factor. For years, researchers have suspected that modern eating patterns might contribute to the rising cases of IBD worldwide. A new international study now highlights a potential link between IBD and a specific food group—ultraprocessed grains.
Published in the June issue of the American Journal of Gastroenterology, this research was led by Dr. Neeraj Narula at McMaster University in Canada. It analyzed data from over 124,000 individuals across 21 countries.
Over recent decades, IBD rates have surged in many regions, coinciding with dramatic shifts in dietary habits. Today’s diets often feature more packaged and heavily processed foods than those of previous generations. Scientists are exploring whether this dietary change impacts digestive health.
Ultraprocessed foods undergo extensive industrial modification and typically contain ingredients uncommon in home-cooked meals. These may include preservatives, flavor enhancers, emulsifiers, sweeteners, colorings, and various additives. Foods made from ultraprocessed grains include many packaged breads, breakfast cereals, crackers, snacks, pastries, and other grain-based products heavily altered during manufacturing.
To investigate the connection between these foods and IBD, researchers utilized data from the Prospective Urban Rural Epidemiology (PURE) study. This large-scale project tracks participants over many years to assess how lifestyle and environmental factors influence health outcomes.
Participants provided detailed food frequency questionnaires, enabling researchers to estimate their ultraprocessed grain intake. Based on responses, individuals were categorized into groups according to consumption levels.
Findings indicated a clear trend: those consuming the highest amounts of ultraprocessed grains had a significantly increased risk of developing IBD compared to those consuming the least. After adjusting for various health factors, researchers found that individuals eating at least 19 grams of ultraprocessed grains daily had an 86% higher risk than those eating less than 9 grams.
The study also examined overall ultraprocessed food consumption, revealing even more alarming results. People who ate five or more servings of ultraprocessed foods each day faced nearly four times the risk of developing IBD compared to those consuming fewer than one serving daily.
Interestingly, some grain products appeared to be linked with a lower risk. For example, fresh bread and rice consumption were associated with a decreased likelihood of IBD, suggesting that the degree of processing plays a crucial role rather than the grains themselves.
Scientists are still working to understand exactly how ultraprocessed foods may impact digestive health. One theory involves the gut microbiome—the community of bacteria and microorganisms living in the intestines. Diet is known to influence this microbial population significantly.
Certain additives found in ultraprocessed products might disrupt the balance of beneficial bacteria or damage the intestinal lining. These alterations could promote inflammation, especially in vulnerable individuals. Additionally, some researchers believe that highly processed foods could impair immune function and trigger increased inflammatory responses.
This research is especially significant because IBD often develops during adolescence or early adulthood and typically requires lifelong management. Although current treatments help control symptoms, there is no cure, making prevention a critical public health goal.
However, it’s important to recognize the limitations of this study. Being observational, it identifies associations rather than definitive cause-and-effect relationships. People who consume large amounts of ultraprocessed foods may have other lifestyle factors influencing their risk, and although many variables were controlled for, some unknown factors might still influence the results. Dietary data was self-reported, which can sometimes lead to inaccuracies. Nonetheless, the large sample size, international scope, and long follow-up strengthen confidence in the findings.
Overall, this study offers some of the strongest evidence to date that ultraprocessed grain products could contribute to the development of IBD. The results reinforce recommendations to focus on whole foods and limit consumption of highly processed items whenever possible. While more research is needed to understand the biological mechanisms, reducing intake of ultraprocessed foods might be a crucial step toward improving gut health and decreasing the global burden of IBD.
If you’re interested in maintaining gut health, consider exploring studies on probiotics’ protective effects and how incorporating mycoprotein into your diet may lower the risk of bowel cancer and support overall digestive wellbeing.
For further insights, review recent research about how food additives impact gut health and learn which foods are best for nurturing a healthy digestive system.

