Cohort studyindependent cross-checkabstract checked I-CAN-112 standard review
Sugary drinks and cancer risk in France
Sugary drink consumption and risk of cancer: results from NutriNet-Santé prospective cohort.
Overview
Chazelas E et al.. BMJ 2019 · PMID 31292122 · DOI 10.1136/bmj.l2408
Each extra 100 mL of sugary drinks per day was linked to 18% higher cancer risk.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Sugary drinks and cancer.
- How was the study done?
Prospective cohort.
- How many people, animals or samples were studied?
101,257 adults.
- What was actually found?
Higher risk with sugary drinks.
- How large was the observed effect?
sHR 1.18 per 100 mL/d.
- What do the results mean in everyday life?
Limiting sugary drinks is sensible.
- What are the study's limitations?
Observational; short follow-up.
- What does it say about Elawady's specific claim?
Contradicts 'no need to fear sugar' for prevention.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Effects in patients already diagnosed.
Scientific in-depth review
1. Full reference
- Authors
- Chazelas E et al.
- Journal
- BMJ
- Year
- 2019
- Identifier
- PMID 31292122 DOI 10.1136/bmj.l2408
- Verification
- verified – PubMed efetch 2026-10-26 + Crossref
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
ICMJE forms: no relevant financial relationships (PubMed record)
2. Research question
Sugary drinks, artificially sweetened beverages and cancer risk
3. Study design and population
- Study design
- Cohort study – Prospective cohort (NutriNet-Sante)
- Population
French adults
- Country
France
- Period
2009-2017 (median follow-up 5.1 years)
- Sample size
101,257; 2,193 cancer cases
- Inclusion and exclusion criteria
Adults >=18 years with repeated 24-h records
4. Methods and endpoints
- Exposure / intervention
Sugary drinks (incl. 100% fruit juice), artificially sweetened beverages
- Comparator
Lower intake
- Endpoints
Overall, breast, prostate, colorectal cancer
- Statistical methods
Fine and Gray competing-risk models
5. Actual results
- Results
Sugary drinks per 100 mL/day: overall cancer sHR 1.18 (1.10-1.27); breast cancer 1.22 (1.07-1.39). 100% fruit juice: 1.12 (1.03-1.23). Artificially sweetened beverages not associated.
- Absolute risks
not reported in abstract
- Authors' conclusion
Sugary drinks were positively associated with overall and breast cancer risk; replication needed.
6. Strengths
- Large cohort
- Repeated 24-h records
7. Weaknesses
- Short follow-up
- Observational
- Volunteer cohort
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
Residual confounding, reverse causation.
9. Assessment of the statistical interpretation
CIs log-symmetric (recalculated).
10. Relevance to the specific claim
Indirect for patients (incidence, not prognosis); shows sugar intake is not neutral for cancer risk.
11. Independent contrary findings
Does not show that sugar 'feeds' an existing tumour.
12. Transferability to Germany and Europe
High (French cohort).
13. Overall methodological judgement
Supports caution about sugary drinks; relevant to prevention claims.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | indirect |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Replication; mechanisms (weight vs direct).
15. Linked fact checks
- The idea that 'sugar feeds cancer' should be dropped: sugar feeds every cell (and microbe), so cancer patients need not fear sugar. – Studies contradicting or limiting the claim
- Third-party site: the Tayebat system can serve as a preventive lifestyle against cancer (less processed meat, refined sugar, fried food, soft drinks), not as treatment; cancer patients must follow their oncology team and keep screening. – Studies supporting the claim
- Cross-system summary: avoiding the system's forbidden foods (industrial eggs, chicken, dairy, white flour, UPF, soft drinks, leafy greens, legumes, acid blockers, supplements) prevents cancer. – Studies supporting the claim