Meta-analysiscited by the Tayebat archiveabstract only checked★ key study A-DRY-05 in-depth review
Half a million women: dairy foods not linked to ovarian cancer
Dairy products and ovarian cancer: a pooled analysis of 12 cohort studies.
Overview
Genkinger JM et al.. Cancer Epidemiol Biomarkers Prev 2006 · PMID 16492930 · DOI 10.1158/1055-9965.EPI-05-0484
No link for milk, cheese, yogurt or calcium; borderline result only for very high lactose.
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 ovarian cancer.
- How was the study done?
Pooled raw data from 12 cohorts.
- How many people, animals or samples were studied?
553,217 women, 2,132 cases.
- What was actually found?
No association with dairy foods; lactose >=30 g/d borderline.
- How large was the observed effect?
RR 1.19 (1.01-1.40), trend P=0.19.
- What do the results mean in everyday life?
Ordinary dairy intake not linked to ovarian cancer.
- What are the study's limitations?
Few cases in high-intake groups.
- What does it say about Elawady's specific claim?
Mostly contradicts the archive's use.
- Do the results apply to Germany and Europe?
Moderate-high.
- What can explicitly not be concluded from this study?
That dairy causes ovarian cancer.
Scientific in-depth review
1. Full reference
- Authors
- Genkinger JM, Hunter DJ, Spiegelman D, Anderson KE, Arslan A, Beeson WL, Buring JE, Fraser GE, Freudenheim JL, Goldbohm RA, Hankinson SE, Jacobs DR, Koushik A, Lacey JV, Larsson SC, Leitzmann M, McCullough ML, Miller AB, Rodriguez C, Rohan TE, Schouten LJ, Shore R, Smit E, Wolk A, Zhang SM, Smith-Warner SA
- Journal
- Cancer Epidemiol Biomarkers Prev
- Year
- 2006
- Identifier
- PMID 16492930 DOI 10.1158/1055-9965.EPI-05-0484
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
Grants listed in PubMed: NCI NIH HHS
2. Research question
Are dairy foods, lactose and calcium associated with epithelial ovarian cancer?
3. Study design and population
- Study design
- Meta-analysis – Pooled analysis of primary data from 12 prospective cohorts (Pooling Project).
- Population
Women in 12 cohorts (North America, Europe)
- Country
Multinational
- Period
Cohort-specific
- Sample size
553,217 women; 2,132 cases
- Inclusion and exclusion criteria
Prospective cohorts in the Pooling Project.
4. Methods and endpoints
- Exposure / intervention
Milk, cheese, yogurt, ice cream, lactose, calcium.
- Comparator
Lowest intake categories (lactose <10 g/d)
- Endpoints
Epithelial ovarian cancer and subtypes.
- Statistical methods
Cox models per study pooled by random effects.
5. Actual results
- Results
No significant associations for milk, cheese, yogurt, ice cream, dietary or total calcium. Lactose >=30 vs <10 g/d pooled RR 1.19 (1.01-1.40), P trend 0.19. Subtypes similar.
- Absolute risks
not reported
- Authors' conclusion
Overall no associations for specific dairy foods or calcium; modest elevation for lactose at a level equal to >=3 servings of milk/day deserves further examination.
6. Strengths
- Primary-data pooling, harmonised analysis
- Large sample
7. Weaknesses
- Few cases per subgroup
- Single dietary assessment in many cohorts
- Multiple comparisons
8. Risk of bias
- Orienting tool
- ROBINS-E
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Strong design for observational evidence; confounding still possible.
9. Assessment of the statistical interpretation
Borderline lactose result with non-significant trend; likely compatible with chance.
10. Relevance to the specific claim
Central to C-DRY-05; largely contradicts it.
11. Independent contrary findings
Its own main result.
12. Transferability to Germany and Europe
Includes European cohorts.
13. Overall methodological judgement
Strong pooled analysis; overall null for dairy foods.
| 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) | taken out of context |
14. Open questions
Very high lactose and subtypes.
15. Linked fact checks
- Dairy and lactose increase ovarian cancer risk (about 19% higher; serous ovarian cancer doubled in heavy milk drinkers). – Studies with mixed or unclear results
Use by the Tayebat archive
Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.
- What the archive says about the study
Lactose intake >=30 g/day raised ovarian cancer risk by 19% compared with <10 g/day (EN); narrative/AR headline: '19% per additional 10 g lactose'.
- A. What was actually studied?
Dairy foods, lactose, calcium and ovarian cancer.
- B. What did the authors find?
No association for dairy foods or calcium; lactose >=30 vs <10 g/d RR 1.19, trend NS.
- C. What conclusions do the authors themselves draw?
Overall no associations; lactose deserves further study.
- D. What does the archive derive from it?
Presented as evidence that dairy raises ovarian cancer risk.
- E. Is this derivation scientifically justified?
Not justified: selects the one borderline sub-result, misstates it as a per-10 g dose effect, and omits the main null finding.
- Adequacy of the interpretation (by the archive)
- taken out of context