IBD Patients Often Have Inadequate Diets

Kelly Lambert, PhD

It has been long known that diet decisions can increase the risk of developing inflammatory bowel disease (IBD), but new research shows poor diet might also be common among patients diagnosed with the disease.

A team, led by Kelly Lambert, School of Medicine, Faculty of Science, Medicine and Health, Illawarra Health and Medical Research Institute, University of Wollongong, evaluated dietary intake of adult IBD patients, including macronutrients, micronutrients, and food group data.

The Importance of Diet

Genetics, dysfunction in inflammatory responses by the innate and adaptive immune system, environmental exposure during childhood, diet, and the gut microbiota have been shown to contribute to the development and progression of the IBD.

Poor diets and nutritional habits has been linked to a number of negative outcomes, including the development of malnutrition, micronutrient deficiencies, anemia, and osteoporosis for IBD patients.

Studies show diets high in total fat, polyunsaturated fatty acids, soft drinks and meat and low intakes of fiber from fruits and vegetables are associated with the development of IBD.

This link is currently being examined in clinical trials, but thus far there has been no compressive systematic review of the dietary intake of IBD patients.

Data Review

In the study, the researchers examined various databases for cohort, case-control, or cross-sectional studies involving dietary intake for adults.

The team collected and pooled data for the studies between January 1, 2000 and September 25, 2020, which were reported as weighted mean intakes for all adults with IBD; Crohn's disease; ulcerative colitis; active disease; remission; males; females.

The investigators also used a random-effects meta-analysis model to compare the dietary intake of IBD patients with a healthy control group.

There were 40 studies identified, 19 of which were included in the final analysis.

Food Choices

Results show inadequate energy for all subgroups of adults with IBD (mean intake in adults with IBD 1980 ± 130 kcal), as well as fiber (14 ± 4 g), folate (246 ± 33 mg) and calcium (529 ± 114 mg) per day.

Specific food items were identified as being under consumed by IBD patients, including breads and cereals, legumes, fruit, vegetables, and dairy. This is consistent with the results of previous research.

In comparison to the healthy control groups, IBD patients consumed significantly less dietary fiber (SMD −0.59; 95% CI, −0.73 to −0.46).

“This review provides improved clarity about the dietary intake of adults with IBD,” the authors wrote. “Future attention is required to improve diet quality and increase understanding of factors influencing dietary intake in IBD.”

There was also specific differences found between patients with Crohn’s disease and patients with ulcerative colitis.

“For adults with ulcerative colitis, they were found to consume significantly more fat and copper compared to healthy controls,” the authors wrote. “Adults with Crohn's disease consumed significantly less protein, iron and fiber compared to healthy controls.”

The study, “Systematic review with meta-analysis: dietary intake in adults with inflammatory bowel disease,” was published online in Alimentary Pharmacology & Therapeutics.