Meta-analysisindependent cross-checkabstract only checked I-DRY-11 standard review
Milk linked to lower bowel cancer risk
Dairy products and colorectal cancer risk: a systematic review and meta-analysis of cohort studies.
Overview
Aune D et al.. Ann Oncol 2012 · PMID 21617020 · DOI 10.1093/annonc/mdr269
Total dairy RR 0.83 per 400 g/day.
Does the study support the specific claim? No · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Dairy and colorectal cancer.
- How was the study done?
Meta-analysis.
- How many people, animals or samples were studied?
19 cohorts.
- What was actually found?
Lower risk with milk/dairy.
- How large was the observed effect?
RR 0.83 (0.78-0.88).
- What do the results mean in everyday life?
Possible benefit.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Shows a trade-off the archive omits.
- Do the results apply to Germany and Europe?
Includes Europe.
- What can explicitly not be concluded from this study?
Causation.
Scientific in-depth review
1. Full reference
- Authors
- Aune D et al.
- Journal
- Ann Oncol
- Year
- 2012
- Identifier
- PMID 21617020 DOI 10.1093/annonc/mdr269
- 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
Dairy and colorectal cancer risk.
3. Study design and population
- Study design
- Meta-analysis – Systematic review and dose-response meta-analysis of cohorts (WCRF).
- Population
Adults in 19 cohorts
- Country
Multinational
- Period
Search to May 2010
- Sample size
19 cohorts
- Inclusion and exclusion criteria
Prospective studies.
4. Methods and endpoints
- Exposure / intervention
Total dairy, milk, cheese
- Comparator
Per dose
- Endpoints
Colorectal cancer.
- Statistical methods
Random effects.
5. Actual results
- Results
Total dairy RR 0.83 (0.78-0.88) per 400 g/d; milk 0.91 (0.85-0.94) per 200 g/d; cheese 0.96 (0.83-1.12) per 50 g/d; restricted to colon cancer.
- Absolute risks
not reported
- Authors' conclusion
Milk and total dairy, but not cheese, associated with reduced colorectal cancer risk.
6. Strengths
- Dose-response; low heterogeneity
7. Weaknesses
- Observational
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
Standard methods.
9. Assessment of the statistical interpretation
Consistent inverse association.
10. Relevance to the specific claim
Limits C-DRY-04 (benefit-harm trade-off).
11. Independent contrary findings
n/a
12. Transferability to Germany and Europe
Includes Europe.
13. Overall methodological judgement
Dairy associated with lower bowel cancer risk.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | some concerns |
| Precision of results | high |
| 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
Causality (calcium).
15. Linked fact checks
- Dairy consumption increases prostate cancer risk (7% per 400 g/day; 34% for more than 2.5 servings/day). – Studies contradicting or limiting the claim