Meta-analysisindependent cross-checkabstract checked I-MEAT-04 standard review
Cutting red meat changes cancer risk only slightly
Reduction of Red and Processed Meat Intake and Cancer Mortality and Incidence: A Systematic Review and Meta-analysis of Cohort Studies.
Overview
Han MA et al.. Ann Intern Med 2019 · PMID 31569214 · DOI 10.7326/M19-0699
Very small absolute reductions; low certainty.
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?
Meat reduction and cancer.
- How was the study done?
Meta-analysis with GRADE.
- How many people, animals or samples were studied?
>6 million people.
- What was actually found?
Very small effects.
- How large was the observed effect?
Not quantified in abstract.
- What do the results mean in everyday life?
Benefits of cutting meat are small for an individual.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Limits strength of the meat rule's benefits.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
That meat is safe in any amount.
Scientific in-depth review
1. Full reference
- Authors
- Han MA et al.
- Journal
- Ann Intern Med
- Year
- 2019
- Identifier
- PMID 31569214 DOI 10.7326/M19-0699
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
Reduction of red/processed meat and cancer mortality/incidence.
3. Study design and population
- Study design
- Meta-analysis – Systematic review and dose-response meta-analysis of cohorts with GRADE (NutriRECS).
- Population
>6 million participants (56 cohorts)
- Country
Multinational
- Period
To April 2019
- Sample size
118 articles
- Inclusion and exclusion criteria
Cohorts >1000 adults.
4. Methods and endpoints
- Exposure / intervention
Unprocessed red and processed meat
- Comparator
Reduction of 3 servings/week
- Endpoints
Cancer mortality and incidence.
- Statistical methods
Dose-response; GRADE.
5. Actual results
- Results
Low-certainty evidence: reduction of 3 servings/week of unprocessed meat associated with a very small reduction in overall cancer mortality; low/very low certainty for very small decreases with processed meat reduction (overall cancer mortality, prostate cancer mortality, oesophageal, colorectal, breast cancer incidence).
- Absolute risks
Described as very small absolute effects.
- Authors' conclusion
Possible absolute effects are very small; certainty low to very low.
6. Strengths
- GRADE; absolute effects
7. Weaknesses
- Methodological choices debated (comments in literature)
- Article corrected
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Rigorous methods; debated framing.
9. Assessment of the statistical interpretation
Emphasises absolute over relative effects.
10. Relevance to the specific claim
Limits C-MEAT-01.
11. Independent contrary findings
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Small absolute effects, low certainty.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
n/a
15. Linked fact checks
- Red meat should be limited: beef/buffalo at most once a week and lamb twice a week (protein not every day). – Studies contradicting or limiting the claim