Cohort studyindependent cross-checkabstract only checked I-EGG-03 standard review
Eggs and heart disease in 0.5 million Chinese adults
Associations of egg consumption with cardiovascular disease in a cohort study of 0.5 million Chinese adults.
Overview
Qin C et al.. Heart 2018 · PMID 29785957 · DOI 10.1136/heartjnl-2017-312651
Daily egg eaters had a lower risk of heart disease and stroke.
Does the study support the specific claim? No · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Is egg consumption associated with CVD subtypes in Chinese adults?
- How was the study done?
Prospective cohort (China Kadoorie Biobank)
- How many people, animals or samples were studied?
461,213 participants; 83,977 CVD cases; 9,985 CVD deaths; Adults 30-79 from 10 regions, free of cancer, CVD, diabetes
- What was actually found?
Daily vs non-consumers: CVD HR 0.89 (0.87-0.92); IHD 0.88; MCE 0.86; haemorrhagic stroke 0.74; ischaemic stroke 0.90; 18% lower CVD death.
- How large was the observed effect?
Stratified Cox HR
- What do the results mean in everyday life?
No sign of harm at moderate intake.
- What are the study's limitations?
Low intake range; Reverse causation possible
- What does it say about Elawady's specific claim?
Contradicts.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Cannot prove benefit.
Scientific in-depth review
1. Full reference
- Authors
- Qin C et al.
- Journal
- Heart
- Year
- 2018
- Identifier
- PMID 29785957 DOI 10.1136/heartjnl-2017-312651
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
None declared; MRC, Wellcome Trust
2. Research question
Is egg consumption associated with CVD subtypes in Chinese adults?
3. Study design and population
- Study design
- Cohort study – Prospective cohort (China Kadoorie Biobank)
- Population
Adults 30-79 from 10 regions, free of cancer, CVD, diabetes
- Country
China
- Period
Recruitment 2004-2008
- Sample size
461,213 participants; 83,977 CVD cases; 9,985 CVD deaths
- Inclusion and exclusion criteria
Free of prior cancer, CVD, diabetes
4. Methods and endpoints
- Exposure / intervention
Egg consumption frequency
- Comparator
Never/rare
- Endpoints
CVD, IHD, major coronary events, haemorrhagic and ischaemic stroke
- Statistical methods
Stratified Cox HR
5. Actual results
- Results
Daily vs non-consumers: CVD HR 0.89 (0.87-0.92); IHD 0.88; MCE 0.86; haemorrhagic stroke 0.74; ischaemic stroke 0.90; 18% lower CVD death.
- Absolute risks
not reported
- Authors' conclusion
Moderate egg consumption (up to <1 egg/day) associated with lower CVD risk.
6. Strengths
- Very large
7. Weaknesses
- Low intake range
- Reverse causation possible
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; low intakes.
9. Assessment of the statistical interpretation
Inverse associations; possibly confounded.
10. Relevance to the specific claim
11. Independent contrary findings
Inverse associations may be confounded.
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Contradicts harm claim in Asian setting.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | some concerns |
| Precision of results | high |
| Directness | direct |
| Reproducibility | replicated |
| Consistency with the overall evidence | mixed |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Mechanism of inverse association.
15. Linked fact checks
- Higher egg (and dietary cholesterol) intake increases the risk of cardiovascular disease and all-cause mortality (each additional half egg per day: +6% CVD, +8% mortality). – Studies contradicting or limiting the claim