— French fries, sports/energy drinks had strongest association in large U.S. study

by Diana Swift, Contributing Writer April 29, 2020

Foods typically labeled as junk food showed an association with inflammatory bowel disease (IBD) among U.S. adults in a secondary analysis of the National Health Interview Survey 2015.

Examining 2015 data from the annual cross-sectional health survey, Moon K. Han, PhD, of the Institute of Biomedical Sciences at Georgia State University in Atlanta, and colleagues found that french fries in particular were consumed by more people with IBD, who also drank less 100% fruit juice and ate more cookies and cheese than the non-IBD population.

The odds ratios of having had a diagnosis of IBD rose significantly with the intake of fries (OR 1.60, 95% CI 1.14-2.25) and sports and energy drinks (OR 1.46, 95% CI 1.07-1.97). In contrast, the odds fell with the intake of popcorn (OR 0.73, 95% CI 0.54-0.97) and milk (OR 0.70, 95% CI 0.49-0.99).

“[The] current study suggests intake of foods typically perceived as unhealthy as a contributing trait of IBD prevalence in the U.S.,” the researchers wrote in their study online in PLoS One. “Understanding the role of food intake in IBD risk/prevalence would benefit from identifying other environmental factors (i.e., food desert), food processing (i.e., frying), and potential bioactive food components that can induce intestinal inflammation that can increase the individual’s susceptibility to IBD.”

The study also found that respondents who had consumed regular soda in the past 30 days had 1.14 times the likelihood of having received a diagnosis of IBD.

“In looking at the association of food and IBD regardless of whether you drank regular soda in the past 30 days, when fitted into a statistical model, we found that consumption of regular soda was associated with a slightly higher likelihood of having been told one has IBD, with an odds ratio of 1.006,” Han told MedPage Today.

Furthermore, compared with the non-IBD population, people who had ever smoked were not unexpectedly more prevalent in the IBD population, the researchers reported. And while a greater proportion of the IBD population was identified as current drinkers rather than former drinkers, this percentage was significantly less compared with the population without IBD.

The team also found that people with IBD were more likely to have been a former drinker (25.68%) than the non-IBD general population (14.06%), and that individuals with IBD were also more likely to drink infrequently compared with the non-IBD population.

While IBD was least prevalent in the underweight population with a body mass index (BMI) of less than 18.5, the differential distribution of all levels of BMI in the IBD population did not notably differ from that in the general population, Han and co-authors reported. They also noted that a change in health behaviors over time was greater in the cohort with a disease diagnosis, including IBD, than in healthy controls.

“In future studies I hope to investigate how the food affects gut immunity through gene expression dysregulation and microbiota activities, while focusing on the potential mediating effect of how the food is prepared and processed,” Han said.

James D. Lewis, MD, MSCE, professor of medicine and epidemiology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, who was not involved with the study, said the findings provide a snapshot of the dietary patterns of patients with self-reported IBD.

He cautioned, however, that the study had several design limitations, such as a reliance on a self-reported diagnosis of IBD, lack of data on current symptoms of inflammation, and dependence on food-frequency questionnaires to estimate dietary patterns. “Nonetheless, these data provide a global picture of what foods patients with IBD are consuming and how this compares to the general population,” Lewis told MedPage Today.

“The higher rates of consumption of fried potatoes is particularly interesting,” he continued. “However, we should be careful not to assume that the dietary patterns observed are causative for IBD when it is equally likely that the reverse could be true.”

Stacy Cavagnaro, RD, of the Cleveland Clinic’s Inflammatory Bowel Disease Medical Home, who was also not involved with the research, emphasized that the results pertain to patients who have already received an IBD diagnosis rather than before diagnosis.

“There is no way to know if their diet had changed after diagnosis,” she told MedPage Today. “There is also no way of knowing if a patient was in a flare or not in a flare at the time of filling out the food questionnaire. While we certainly need more studies to examine the role of diet and IBD, and this study does support limiting the amount of processed foods, it is not strong enough to make any conclusions that would affect current practice and recommendations.”

Recent evidence has suggested that making diet a focus of IBD management remains challenging, and dietary restrictions such as avoiding red and processed meats do not appear to have the desired effects on disease relapse.

Han and co-authors also noted other study limitations, including the inability to make inferences about the causal relationship of food intake and IBD development since there was no longitudinal follow-up and no cross-referencing to medical records. In addition, responses on the food questionnaires were subject to recall bias, and the health survey was not designed to ask questions specifically related to IBD conditions, meaning that it was not possible to differentiate between ulcerative colitis and Crohn’s disease. In addition, the survey did not ask about disease duration or activity or about the impact of diagnosis on changes in health-related behaviors and food consumption patterns.