Meta-analysisindependent cross-checkabstract checked★ key study I-MEAT-101 in-depth review
More red meat, more heart disease and diabetes in studies
Red meat consumption, cardiovascular diseases, and diabetes: a systematic review and meta-analysis.
Overview
Shi W et al.. Eur Heart J 2023 · PMID 37264855 · DOI 10.1093/eurheartj/ehad336
Each 100 g/day of unprocessed red meat was linked to 11% higher CVD risk; each 50 g/day of processed meat to 26%.
Does the study support the specific claim? Yes · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Pool studies on red meat, CVD and diabetes.
- How was the study done?
Meta-analysis.
- How many people, animals or samples were studied?
Over 4 million people.
- What was actually found?
Positive associations, stronger for processed meat.
- How large was the observed effect?
HR 1.11 and 1.26.
- What do the results mean in everyday life?
Eating red meat in moderation and little processed meat is sensible.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Supports limiting red meat.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
It cannot prove causation or define a safe level.
Scientific in-depth review
1. Full reference
- Authors
- Shi W et al.
- Journal
- Eur Heart J
- Year
- 2023
- Identifier
- PMID 37264855 DOI 10.1093/eurheartj/ehad336
- 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
Authors declare no conflict of interest; non-US government support (PubMed).
2. Research question
Are unprocessed and processed red meat associated with CVD and diabetes, and do associations differ by sex and setting?
3. Study design and population
- Study design
- Meta-analysis – Systematic review and dose-response meta-analysis of observational studies (and RCTs searched)
- Population
43 observational studies for CVD (4,462,810 participants); 27 for diabetes (1,760,774)
- Country
Multinational (western and eastern settings)
- Period
Search to 30 June 2022
- Sample size
CVD 4.46 million; diabetes 1.76 million
- Inclusion and exclusion criteria
not detailed in abstract
4. Methods and endpoints
- Exposure / intervention
Unprocessed red meat (per 100 g/day); processed red meat (per 50 g/day)
- Comparator
Lower intake
- Endpoints
CVD, CHD, stroke, heart failure, T2DM, gestational diabetes
- Statistical methods
Random-effects dose-response meta-analysis; subgroups by sex and setting
5. Actual results
- Results
Unprocessed red meat per 100 g/day: CVD HR 1.11 (1.05-1.16); processed red meat per 50 g/day: CVD HR 1.26 (1.18-1.35); positive associations with CVD subtypes, T2DM and GDM; associations with stroke and T2DM higher in western settings; no sex difference.
- Absolute risks
not reported
- Authors' conclusion
Unprocessed and processed red meat consumption are both associated with higher risk of CVD, its subtypes and diabetes, stronger in western settings.
6. Strengths
- Large, recent, dose-response
- Explores eastern vs western settings
7. Weaknesses
- Observational
- Residual confounding by lifestyle
- Overlaps with earlier meta-analyses
8. Risk of bias
- Orienting tool
- AMSTAR 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Abstract-level; simplified judgement.
9. Assessment of the statistical interpretation
CI for unprocessed meat slightly asymmetric on log scale (0.056/0.044), compatible with rounding. At 50-71 g/day (WCRF goal) the log-linear CVD RR vs zero is about 1.05-1.08 (stats/C-MEAT-01_red_meat_dose.py).
10. Relevance to the specific claim
Supports limiting red meat, particularly processed meat; the system's limit is consistent with this.
11. Independent contrary findings
Burden of Proof (I-MEAT-102) rates the unprocessed red meat evidence as weak.
12. Transferability to Germany and Europe
Western settings; Egypt intermediate.
13. Overall methodological judgement
Supports the general direction of limiting red meat with low-certainty observational evidence.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Effect of very low intakes (1-3 portions/week).
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 supporting the claim