Meta-analysisindependent cross-checkabstract checked I-UPF-110 in-depth review

Ultra-processed food and inflammatory bowel disease: pooled data

Food Processing and Risk of Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Overview

Narula N et al.. Clin Gastroenterol Hepatol 2023 · PMID 36731590 · DOI 10.1016/j.cgh.2023.01.012

Across five cohorts, high UPF intake was linked to 71% more Crohn's disease but not to ulcerative colitis.

Does the study support the specific claim? Partly · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: To pool cohorts on UPF and IBD.
How was the study done?: Meta-analysis of 5 cohorts.
How many people, animals or samples were studied?: Over 1 million people.
What was actually found?: Crohn's disease associated; ulcerative colitis not.
How large was the observed effect?: CD HR 1.71 (1.37-2.14).
What do the results mean in everyday life?: The link concerns Crohn's disease specifically.
What are the study's limitations?: Few cohorts; observational.
What does it say about Elawady's specific claim?: Partly supports C-UPF-05.
Do the results apply to Germany and Europe?: Applicable.
What can explicitly not be concluded from this study?: Cannot prove causation.

Authors: Narula N et al.
Journal: Clin Gastroenterol Hepatol
Year: 2023
Identifier: PMID 36731590 DOI 10.1016/j.cgh.2023.01.012
Verification: verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: No COI statement in PubMed record

Is food processing associated with risk of Crohn's disease (CD) and ulcerative colitis (UC)?

Study design: Meta-analysis – Systematic review and meta-analysis of cohort studies
Population: Adults in cohort studies
Country: Multinational
Period: Search to October 2022
Sample size: 5 cohorts; 1,068,425 participants; 916 CD and 1,934 UC cases
Inclusion and exclusion criteria: Cohort studies of food processing and CD/UC

Results: UPF: CD HR 1.71 (1.37-2.14; I2 0%); UC HR 1.17 (0.86-1.61; I2 74%). Unprocessed/minimally processed foods: CD HR 0.71 (0.53-0.94); UC HR 0.84 (0.68-1.02).
Absolute risks: not reported in abstract
Authors' conclusion: Higher UPF and lower unprocessed food intakes are associated with higher risk of CD but not UC.

CIs log-symmetric (stats/C-UPF-05_ibd.py).

Pooled evidence: association with CD, not UC; refines the claim from 'IBD' to Crohn's disease.

UC null.

Includes European cohorts.

Supports CD association; not UC.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	moderate
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Mechanisms; specific components.