Cohort studyindependent cross-checkabstract checked I-UPF-111 standard review
Ultra-processed food and Crohn's disease in US health workers
Ultra-processed Foods and Risk of Crohn's Disease and Ulcerative Colitis: A Prospective Cohort Study.
Overview
Lo CH et al.. Clin Gastroenterol Hepatol 2022 · PMID 34461300 · DOI 10.1016/j.cgh.2021.08.031
In 245,000 adults, the highest UPF eaters had 70% more Crohn's disease, but no more ulcerative colitis.
Does the study support the specific claim? Partly · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
To link UPF to Crohn's disease and colitis.
- How was the study done?
Three US cohorts.
- How many people, animals or samples were studied?
245,112 adults.
- What was actually found?
More Crohn's disease; no link with ulcerative colitis.
- How large was the observed effect?
CD HR 1.70.
- What do the results mean in everyday life?
The rare disease Crohn's may be linked to UPF.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Partly supports C-UPF-05.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Cannot prove causation.
Scientific in-depth review
1. Full reference
- Authors
- Lo CH et al.
- Journal
- Clin Gastroenterol Hepatol
- Year
- 2022
- Identifier
- PMID 34461300 DOI 10.1016/j.cgh.2021.08.031 · PMC8882700
- 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; funding listed: NCI NIH HHS, NIDDK NIH HHS
2. Research question
Is UPF consumption associated with risk of CD and UC?
3. Study design and population
- Study design
- Cohort study – Prospective cohort study (NHS, NHSII, HPFS)
- Population
US health professionals
- Country
USA
- Period
1986-2017
- Sample size
245,112; 5,468,444 person-years; 369 CD and 488 UC
- Inclusion and exclusion criteria
Cohort participants
4. Methods and endpoints
- Exposure / intervention
UPF (FFQ)
- Comparator
Lowest quartile
- Endpoints
Incident CD and UC
- Statistical methods
Cox models
5. Actual results
- Results
Highest vs lowest quartile: CD HR 1.70 (1.23-2.35; P trend 0.0008). Subgroups per SD: UP breads and breakfast foods 1.18 (1.07-1.29); ready-to-eat/heat meals 1.11 (1.01-1.22); sauces, cheeses, spreads, gravies 1.14 (1.02-1.27). No consistent association with UC.
- Absolute risks
CD 6.7 and UC 8.9 per 100,000 person-years overall (stats/C-UPF-05_ibd.py)
- Authors' conclusion
Higher UPF intake was associated with increased risk of incident CD.
6. Strengths
- Large, long follow-up
7. Weaknesses
- Observational
- Health professionals
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Observational.
9. Assessment of the statistical interpretation
Consistent with PURE for CD.
10. Relevance to the specific claim
Replicates the CD association in an independent US population; no UC association.
11. Independent contrary findings
UC null.
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Supports CD part.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Components.
15. Linked fact checks
- Higher ultra-processed food intake raises the risk of inflammatory bowel disease (PURE study: HR 1.82 for >=5 servings/day). – Studies supporting the claim