Randomised controlled trialindependent cross-checkabstract checked I-FAT-108 standard review
Old Australian trial: safflower oil instead of animal fat raised deaths
Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis.
Overview
Ramsden CE et al.. BMJ 2013 · PMID 23386268 · DOI 10.1136/bmj.e8707
Death 17.6% v 11.8% (HR 1.62).
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Re-analyse a 1960s trial of linoleic acid.
- How was the study done?
RCT re-analysis.
- How many people, animals or samples were studied?
458 men after heart events.
- What was actually found?
More deaths with safflower oil.
- How large was the observed effect?
HR 1.62 (1.00-2.64).
- What do the results mean in everyday life?
Seed oils are not clearly protective.
- What are the study's limitations?
Old, small trial.
- What does it say about Elawady's specific claim?
Limits the advice to use seed oils.
- Do the results apply to Germany and Europe?
Applicable with caution.
- What can explicitly not be concluded from this study?
Cannot show olive oil is harmful.
Scientific in-depth review
1. Full reference
- Authors
- Ramsden CE et al.
- Journal
- BMJ
- Year
- 2013
- Identifier
- PMID 23386268 DOI 10.1136/bmj.e8707
- Verification
- verified – PubMed efetch 2026-10-26
- Retracted
- no
- Corrections
Erratum published (BMJ 2013;346:f903) per PubMed CommentsCorrections; no retraction
- Extent checked
- abstract only
- Conflicts of interest and funding
Life Insurance Medical Research Fund of Australia and New Zealand; NIAAA intramural program.
2. Research question
Does replacing saturated fat with linoleic acid (safflower oil) reduce deaths after a coronary event?
3. Study design and population
- Study design
- Randomised controlled trial – Re-analysis of recovered data from an RCT (1966-73) plus updated meta-analysis
- Population
Men 30-59 y with recent coronary event
- Country
Australia
- Period
1966-1973
- Sample size
458 (221 intervention, 237 control)
- Inclusion and exclusion criteria
Recent coronary event
4. Methods and endpoints
- Exposure / intervention
Safflower oil and safflower margarine replacing animal fats and common margarines
- Comparator
No dietary instruction
- Endpoints
All-cause, CVD and CHD mortality
- Statistical methods
Intention-to-treat survival analysis
5. Actual results
- Results
All-cause death 17.6% v 11.8%, HR 1.62 (1.00-2.64); CVD death 17.2% v 11.0%, HR 1.70 (1.03-2.80); CHD death 16.3% v 10.1%, HR 1.74 (1.04-2.92). Updated LA trial meta-analysis: CHD death HR 1.33 (0.99-1.79); CVD death 1.27 (0.98-1.65).
- Absolute risks
Absolute increase in all-cause death 5.8 percentage points (NNH ~17) (stats/C-FAT-04_oils.py)
- Authors' conclusion
Substituting dietary linoleic acid for saturated fats increased all-cause, CHD and CVD death in this cohort; no evidence of cardiovascular benefit from LA trials.
6. Strengths
- Randomised
- Hard outcomes
7. Weaknesses
- Old trial; margarines of the era contained trans fat (control arm)
- Small
- Secondary prevention men only
- Single-blind
8. Risk of bias
- Orienting tool
- RoB 2
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Recovered data; era-specific products.
9. Assessment of the statistical interpretation
Borderline significance (lower CI 1.00); small trial.
10. Relevance to the specific claim
The main RCT signal against replacing animal fat with linoleic-acid-rich seed oil; it limits the recommendation of corn/sunflower oil but does not show that olive oil is harmful.
11. Independent contrary findings
I-FAT-01 (overall SFA reduction benefit), I-FAT-05 (cohorts).
12. Transferability to Germany and Europe
Era-specific.
13. Overall methodological judgement
Important caution, low certainty.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | indirect |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | inconsistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Role of trans fats in the comparator.