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The Study

The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers.

In simple terms

This study gave different pills to thousands of men who smoked and watched what happened over many years. It found that one pill (beta carotene) made more men get lung cancer — so we can say it probably caused that harm. But it didn’t prove why, or if it would affect other people.

74%

Analysis score

74/ 90

Maximum 90 for a randomized controlled trial.

Where the score came from

Reporting0
Methodology100
Publication100
Statistical77
Study type (basis of the score)
Randomized Controlled Trial
Level 1b - Individual RCT
What’s the bottom line?

Scientists tested if taking daily vitamin pills (beta-carotene or vitamin E) could stop smokers from getting lung cancer.

Where does this study sit?

Reviews of RCTs (Meta-analyses)

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Randomized Trials
Level 1b
74

74 / 100

Quality score

Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.

Can establish causation

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Key takeaways

Summary

Based on the study abstract and findings.

  1. 1Yes — for every 100 smokers taking beta-carotene, about 2 extra deaths from lung cancer or heart disease occurred over 6 years.
  2. 2Smokers who took 20 mg of beta-carotene daily got 18% more lung cancer and 8% more deaths overall.
  3. 3Vitamin E didn't help prevent lung cancer and caused more deadly brain bleeds.

Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data

Publication

Journal

The New England journal of medicine

Year

1994

Authors

O. Heinonen, D. Albanes

Open Access
4279 citations
Analysis v5
Fit Body Science verdict — we translate health studies into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.