Randomised controlled trialcited by the Tayebat archiveabstract only checked A-SUP-05 standard review
ATBC: beta-carotene raised lung cancer in Finnish smokers
The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers.
Overview
ATBC Study Group. N Engl J Med 1994 · PMID 8127329 · DOI 10.1056/NEJM199404143301501
Beta-carotene raised lung cancer by 18% and deaths by 8%; vitamin E did not prevent lung cancer.
Does the study support the specific claim? Yes · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Cancer prevention in smokers.
- How was the study done?
Factorial RCT.
- How many people, animals or samples were studied?
29,133 men.
- What was actually found?
Harm from beta-carotene.
- How large was the observed effect?
+18% lung cancer.
- What do the results mean in everyday life?
Avoid beta-carotene pills.
- What are the study's limitations?
Men smokers only.
- What does it say about Elawady's specific claim?
Supports C-SUP-02.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Non-smokers.
Scientific in-depth review
1. Full reference
- Authors
- Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group
- Journal
- N Engl J Med
- Year
- 1994
- Identifier
- PMID 8127329 DOI 10.1056/NEJM199404143301501
- Verification
- verified – PubMed E-utilities efetch, 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract; grants: NCI NIH HHS
2. Research question
Do alpha-tocopherol and/or beta-carotene reduce lung and other cancers?
3. Study design and population
- Study design
- Randomised controlled trial – Randomised, double-blind, placebo-controlled 2×2 factorial trial (ATBC)
- Population
Male smokers 50–69 years
- Country
Finland
- Period
5–8 years
- Sample size
29,133
- Inclusion and exclusion criteria
see abstract
4. Methods and endpoints
- Exposure / intervention
Alpha-tocopherol 50 mg/d, beta-carotene 20 mg/d, both
- Comparator
Placebo
- Endpoints
Lung cancer; other cancers; mortality
- Statistical methods
Factorial comparison
5. Actual results
- Results
Lung cancer: alpha-tocopherol −2% (−14 to 12); beta-carotene +18% (3–36). Fewer prostate cancers with alpha-tocopherol; more haemorrhagic stroke deaths with alpha-tocopherol; total mortality +8% (1–16) with beta-carotene.
- Absolute risks
not reported in abstract
- Authors' conclusion
No reduction in lung cancer; supplements may have harmful as well as beneficial effects.
6. Strengths
- Very large RCT
- Long follow-up
7. Weaknesses
- Male smokers only
- Low vitamin E dose
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
- Rationale
Simplified RoB 2.
9. Assessment of the statistical interpretation
See results.
10. Relevance to the specific claim
C-SUP-02; C-SUP-03 (contrasting prostate finding).
11. Independent contrary findings
12. Transferability to Germany and Europe
High: biology and trial populations comparable to European adults.
13. Overall methodological judgement
Robust RCT.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | low |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | essentially correct but incomplete |
14. Open questions
15. Linked fact checks
- Beta-carotene supplements (with or without vitamin A) increased lung cancer and mortality in smokers and asbestos-exposed workers (CARET, ATBC), and the USPSTF recommends against them. – Studies supporting the claim
- High-dose vitamin E (400 IU/day) increases prostate cancer (SELECT, +17%) and may increase all-cause mortality (Miller 2005: +39 per 10,000). – 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
Listed in the archive bibliography of the oral-supplements rule without its own interpretation; used implicitly to support the rule summary that supplements 'failed or caused harm' in large trials.
- A. What was actually studied?
Do alpha-tocopherol and/or beta-carotene reduce lung and other cancers?
- B. What did the authors find?
Lung cancer: alpha-tocopherol −2% (−14 to 12); beta-carotene +18% (3–36). Fewer prostate cancers with alpha-tocopherol; more haemorrhagic stroke deaths with alpha-tocopherol; total mortality +8% (1–16) with beta-carotene.
- C. What conclusions do the authors themselves draw?
No reduction in lung cancer; supplements may have harmful as well as beneficial effects.
- D. What does the archive derive from it?
Confirms CARET for beta-carotene.
- E. Is this derivation scientifically justified?
Yes for beta-carotene; the archive omits that alpha-tocopherol was associated with fewer prostate cancers.
- Adequacy of the interpretation (by the archive)
- essentially correct but incomplete