Cohort studyindependent cross-checkabstract checked★ key study I-FAT-105 in-depth review
Olive oil users lived longer in US cohorts
Consumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults.
Overview
Guasch-Ferre M et al.. J Am Coll Cardiol 2022 · PMID 35027106 · DOI 10.1016/j.jacc.2021.10.041
>7 g/day: 19% lower mortality; similar to other vegetable oils.
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?
Study olive oil and mortality.
- How was the study done?
Two cohorts, 28 years.
- How many people, animals or samples were studied?
92,383 adults.
- What was actually found?
Lower mortality with olive oil.
- How large was the observed effect?
HR 0.81 (0.78-0.84).
- What do the results mean in everyday life?
Olive oil is a healthy choice; other plant oils similar.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Supports allowing olive oil.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Cannot prove causation.
Scientific in-depth review
1. Full reference
- Authors
- Guasch-Ferre M et al.
- Journal
- J Am Coll Cardiol
- Year
- 2022
- Identifier
- PMID 35027106 DOI 10.1016/j.jacc.2021.10.041
- Verification
- verified – PubMed efetch 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
NIH grants; one author received virgin olive oil for PREDIMED trials from producers.
2. Research question
Is olive oil intake associated with total and cause-specific mortality?
3. Study design and population
- Study design
- Cohort study – Two prospective cohorts (NHS, HPFS), FFQ every 4 years, 28 y follow-up
- Population
US women and men free of CVD and cancer
- Country
USA
- Period
1990-2018
- Sample size
92,383 (60,582 women, 31,801 men); 36,856 deaths
- Inclusion and exclusion criteria
Free of CVD/cancer at baseline
4. Methods and endpoints
- Exposure / intervention
Olive oil
- Comparator
Never/rarely
- Endpoints
Total and cause-specific mortality
- Statistical methods
Multivariable Cox; substitution models
5. Actual results
- Results
>7 g/d v never: all-cause HR 0.81 (0.78-0.84); CVD mortality 0.81 (0.75-0.87); cancer 0.83 (0.78-0.89); neurodegenerative 0.71 (0.64-0.78); respiratory 0.82 (0.72-0.93). Replacing 10 g/d margarine, butter, mayonnaise or dairy fat with olive oil: 8-34% lower mortality. No significant associations when olive oil was compared with other vegetable oils combined.
- Absolute risks
not reported
- Authors' conclusion
Higher olive oil intake was associated with lower risk of total and cause-specific mortality.
6. Strengths
- Large, long follow-up
- Substitution analysis
7. Weaknesses
- Observational
- US intakes low
- Healthy-user effects
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
Confounding possible.
9. Assessment of the statistical interpretation
Moderate relative associations; olive oil not different from other vegetable oils.
10. Relevance to the specific claim
Supports allowing olive oil (C-FAT-03) and contradicts avoiding it (C-FAT-04); also shows other vegetable oils were similar, so corn/sunflower are not worse alternatives in this cohort.
11. Independent contrary findings
None for harm.
12. Transferability to Germany and Europe
Applicable.
13. Overall methodological judgement
Consistent with PREDIMED.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | high |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Effects in high-intake Mediterranean/Egyptian settings.
15. Linked fact checks
- Olive oil is an allowed fat in the system. – Studies supporting the claim
- Olive oil (and flaxseed oil) should be avoided because it is adulterated ('it is all fake') and has a problem with its acidity; instead a little corn oil and sunflower oil should be used for frying. – Studies contradicting or limiting the claim