Individuals who consumed more ultraprocessed foods had a significantly increased risk of developing inflammatory bowel disease (IBD) than those who consumed less, according to data from more than 100,000 adults.

“Diet alters the microbiome and modifies the intestinal immune response and so could play a role in the pathogenesis of IBD,” Neeraj Narula, MD, of McMaster University, Hamilton, Ont., and colleagues wrote. Although previous studies have investigated the impact of dietary risk factors on IBD, an association with ultraprocessed foods (defined as foods containing additives and preservatives) in particular has not been examined, they wrote.

In a study published in BMJ, the researchers examined data from 116,087 adults aged 35-70 years from 21 countries between 2003 and 2016 who were part of the large Prospective Urban Rural Epidemiology (PURE) Cohort. Participants completed baseline food frequency questionnaires and were followed at least every 3 years; the median follow-up time was 9.7 years. The primary outcome was the development of Crohn’s disease or ulcerative colitis. In this study, ultraprocessed food included all packaged and formulated foods and beverages that contained food additives, artificial flavors or colors, or other chemical ingredients.

The categories of ultraprocessed foods included processed meat, cold breakfast cereal, various sauces, soft drinks, and fruit drinks, and refined sweetened foods such as candy, chocolate, jam, jelly, and brownies.

The risk of IBD increased among individuals who consumed 1 serving per week or more of processed meat, compared with those who consumed less than 1 serving per week, and the risk increased with the amount consumed (HR, 2.07 for 1 or more servings per day). Similarly, IBD risk was higher among individuals who consumed 100 g/day or more of refined sweetened foods compared with no intake of these foods (HR, 2.58).

Individuals who consumed at least one serving of fried foods per day had the highest risk of IBD (HR, 3.02), the researchers noted. The reason for the association is uncertain, but may occur not only because many fried foods are also processed but also because the action of frying food and the processing of oil, as well as type and quality of oil, might modify the nutrients.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.