Not All Plant-Based Diets Protect Against IBD

TOPLINE:

Consuming a healthy plant-based diet is linked to a reduced risk of developing inflammatory bowel disease (IBD), with an unhealthy plant-based diet showing the opposite effect.

METHODOLOGY: 

• Many proposed diets for IBD emphasize plant foods, but vegetarian diets can still include harmful ingredients like emulsifiers and refined grains.
• This retrospective study used data of adult participants without IBD at baseline from two prospective cohorts: The UK Biobank (n = 187,888; 55% women) and the EPIC-IBD study (n = 341,539; 69.9% women); 2133 UK Biobank participants with valid dietary data who were prediagnosed with IBD were also included.
• Plant-based diet indexes (PDIs) were assessed using 24-hour dietary recalls and food frequency questionnaires, with healthy PDIs assigned positive scores (ranging from 1 to 5) to healthy plant foods (eg, whole grains, fruits, vegetables, nuts, and legumes) and reverse scores to unhealthy plant foods (eg, refined, processed, and sugar-sweetened foods and drinks).

TAKEAWAY:

• In the UK Biobank cohort, higher adherence to healthy PDIs was associated with a lower incidence of IBD (adjusted hazard ratio [aHR], 0.75; P for trend = .003), but higher adherence to unhealthy PDIs was associated with a higher incidence of IBD (aHR, 1.48; P for trend = .001). Similar trends were seen in the EPIC-IBD cohort.
• Intake of sweets and potatoes was associated with an increased incidence of IBD (P = .001 for both), whereas intake of fruits and whole grains showed an inverse association (P < .05 for both).
• Among individuals with established IBD, healthy PDI was associated with a reduced risk for IBD-related surgery (aHR, 0.50; P for trend = .0001), whereas unhealthy PDI was associated with an increased risk (aHR, 2.12; P for trend = .003).
• The association of PDIs with incident IBD and IBD-related surgeries was stronger in participants with a moderate or high genetic risk for IBD and was partially mediated by inflammation.

IN PRACTICE:

“These findings support the current paradigm that plant-based foods should be recommended to all patients with IBD yet underline the possible need for specialized dietetic counseling to ensure the overall quality of the diet,” the authors wrote.

SOURCE:

This study, led by Jie Chen, Yuhao Sun, and Lintao Dan from the Third Xiangya Hospital, Central South University in Changsha, China, was published online in The Lancet Regional Health – Europe.

LIMITATIONS:

The study’s observational nature limited the ability to establish causal inferences due to potential residual confounding. The population primarily comprised European and White adults, thus limiting the finding’s generalizability to other ethnicities and age groups. Constraints in data availability limited the investigation of other important endpoints, such as quality of life, disease activity, and relapse.

DISCLOSURES:

This study was supported by the National Natural Science Foundation of China, Natural Science Fund for Distinguished Young Scholars of Zhejiang Province, National Undergraduate Training Program for Innovation and Entrepreneurship, a CRUK Career Development Fellowship, the “Co-PI” project, and the Natural Science Fund for Excellent Young Scholars of Hunan Province. One author reported coordinating an unrelated study funded by Janssen corporation, receiving financial support, and having a collaboration with a pharmaceutical company.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.