Risk assessmentcited by the Tayebat archivefull text checked A-UPF-20 in-depth review
IARC on aspartame
Carcinogenicity of aspartame, methyleugenol, and isoeugenol.
Overview
Riboli E et al.. Lancet Oncol 2023 · PMID 37454664 · DOI 10.1016/S1470-2045(23)00341-8
IARC placed aspartame in Group 2B ('possibly carcinogenic') on limited evidence.
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?
Hazard classification of aspartame.
- How was the study done?
IARC Monographs meeting summary (news).
- How many people, animals or samples were studied?
Not applicable; Not applicable
- What was actually found?
No abstract in PubMed. Per WHO/IARC/JECFA release (I-SOD-09): Group 2B based on limited evidence in humans (hepatocellular carcinoma), limited in animals, limited mechanistic.
- How large was the observed effect?
Not applicable
- What do the results mean in everyday life?
Hazard category, not proof of risk.
- What are the study's limitations?
Classifies whether aspartame can cause cancer at all (hazard), not how likely it is at normal intake; the evidence in humans, animals and mechanistic studies was all rated 'limited'.
- What does it say about Elawady's specific claim?
Supports C-UPF-08 (fact).
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Cancer risk at normal intake.
Scientific in-depth review
1. Full reference
- Authors
- Riboli E, Beland FA, Lachenmeier DW, Marques MM, Phillips DH, Schernhammer E, Afghan A, Assunção R, Caderni G, Corton JC, de Aragão Umbuzeiro G, de Jong D, Deschasaux-Tanguy M, Hodge A, Ishihara J, Levy DD, Mandrioli D, McCullough ML, McNaughton SA, Morita T, Nugent AP, Ogawa K, Pandiri AR, Sergi CM, Touvier M, Zhang L, Benbrahim-Tallaa L, Chittiboyina S, Cuomo D, DeBono NL, Debras C, de Conti A, El Ghissassi F, Fontvieille E, Harewood R, Kaldor J, Mattock H, Pasqual E, Rigutto G, Simba H, Suonio E, Viegas S, Wedekind R, Schubauer-Berigan MK, Madia F
- Journal
- Lancet Oncol
- Year
- 2023
- Identifier
- PMID 37454664 DOI 10.1016/S1470-2045(23)00341-8
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
Working Group statement: the research unit of one member (J.I.) receives funding from Kagome Co. Ltd, which has links to a company with competing interests for aspartame; all other authors declared none. No funding statement in the full text.
2. Research question
Hazard classification of aspartame.
3. Study design and population
- Study design
- Risk assessment – IARC Monographs Working Group meeting summary (Lancet Oncology news report, Volume 134): hazard identification by 25 scientists from 12 countries, June 2023. Full text is the authors' manuscript deposited in HAL.
- Population
Not applicable
- Country
International (IARC)
- Period
Working Group meeting June 6-13, 2023
- Sample size
Not applicable
- Inclusion and exclusion criteria
IARC Monographs evaluation of published human, animal and mechanistic studies; cohort studies of artificially sweetened beverages (ASB) used as proxy for aspartame exposure where aspartame was the main sweetener.
4. Methods and endpoints
- Exposure / intervention
Aspartame
- Comparator
Not applicable
- Endpoints
Carcinogenic hazard (cancer in humans, experimental animals, mechanistic evidence); for aspartame specifically hepatocellular carcinoma
- Statistical methods
IARC qualitative evidence classification (sufficient/limited/inadequate) by Working Group consensus/majority
5. Actual results
- Results
Aspartame: Group 2B ('possibly carcinogenic to humans') based on 'limited' evidence in humans (hepatocellular carcinoma), 'limited' evidence in experimental animals and 'limited' mechanistic evidence. Human evidence: three studies of ASB and liver cancer reported positive associations overall or in subgroups; in a 10-country European cohort each weekly 330 mL serving of ASB was associated with a 6% higher hepatocellular carcinoma risk (95% CI 3-9%); chance, bias or confounding could not be ruled out. NutriNet-Santé associations with breast, obesity-related and overall cancer were not consistent across studies. Animal studies (Swiss mice, Sprague-Dawley rats) showed tumours, but the Working Group questioned their design, conduct and reporting (e.g. no adjustment for litter effects); a minority favoured Group 2A. Mechanistic: oxidative stress and inflammation in rodents; genotoxicity studies had limitations. Methyleugenol Group 2A; isoeugenol Group 2B.
- Absolute risks
not applicable (hazard identification; no exposure-level risk estimate)
- Authors' conclusion
Aspartame is possibly carcinogenic to humans (Group 2B), based on limited evidence for hepatocellular carcinoma in humans and limited evidence in animals and mechanistic studies.
6. Strengths
- Authoritative international hazard identification
- Transparent statement of evidence streams and of minority opinions
7. Weaknesses
- Hazard identification, not risk assessment: does not address the dose at which any risk occurs
- Human evidence limited to a few observational ASB studies with possible chance, bias or confounding
- Animal studies judged to have design and reporting problems
- Short news summary; detailed reasoning only in the Monograph
8. Risk of bias
- Orienting tool
- none applicable (hazard-identification report; structured judgement)
- Type of assessment
- structured assessment based on the full text by a single reviewer (no formal double review)
- Full formal assessment
- no
- Overall risk of bias
- not assessable
- Rationale
No standard risk-of-bias tool fits an IARC hazard summary. The report itself is a reliable account of the classification; the underlying evidence for aspartame is weak (all three streams 'limited'). Structured single-reviewer judgement; a complete formal assessment requires two independent reviewers.
| Domain | Judgement | Rationale |
|---|---|---|
| Evidence base (human) | high | Few observational studies using ASB as a proxy; confounding and chance not excluded (Working Group). |
| Evidence base (animal) | high | Positive studies from one laboratory series with acknowledged design, conduct and reporting concerns. |
| Process transparency | low | Standard IARC procedures; categories and minority views stated; COI disclosed. |
| Applicability to risk at usual intake | not applicable | IARC classifies hazard only; risk at typical intakes is outside scope (addressed by JECFA, I-SOD-09). |
Full-text review (25 October 2026): Full text now available (previously no abstract). Added: Working Group composition and date, evidence streams (all 'limited'), human evidence (3 ASB-liver cancer studies; EPIC 6% per weekly serving, 95% CI 3-9%), animal-study quality concerns, minority support for 2A, methyleugenol 2A and isoeugenol 2B, COI (Kagome funding of one member's unit). Funding statement not in full text. Structured judgement; overall remains not_assessable.
9. Assessment of the statistical interpretation
The only quantitative human estimate cited is a 6% (3-9%) higher hepatocellular carcinoma risk per weekly ASB serving from one European cohort; IARC judged chance, bias or confounding could not be ruled out. Group 2B signals limited evidence, not demonstrated risk.
10. Relevance to the specific claim
Supports C-UPF-08 (fact).
11. Independent contrary findings
I-SOD-09 (JECFA ADI).
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Correct primary source for the Group 2B classification; the underlying evidence was limited in all three streams and the classification concerns hazard, not risk at usual intake.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | not assessable |
| Precision of results | not applicable |
| Directness | direct |
| Reproducibility | not replicated |
| Consistency with the overall evidence | unknown |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | essentially correct but incomplete |
14. Open questions
Risk at usual intake.
15. Linked fact checks
- In 2023 IARC classified aspartame as 'possibly carcinogenic to humans' (Group 2B). – Studies supporting the claim
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
(Narrative) In 2023 IARC classified aspartame as 'possibly carcinogenic' (Group 2B).
- A. What was actually studied?
Aspartame hazard.
- B. What did the authors find?
Group 2B.
- C. What conclusions do the authors themselves draw?
As above.
- D. What does the archive derive from it?
Presented as evidence of UPF mechanisms.
- E. Is this derivation scientifically justified?
Correct fact. The paper itself states the evidence was 'limited' in humans, animals and mechanistic studies; the archive omits this, the hazard-versus-risk distinction and JECFA's reaffirmed acceptable daily intake (I-SOD-09, not part of this paper).
- Adequacy of the interpretation (by the archive)
- essentially correct but incomplete