Dietary cholesterol and cardiovascular disease: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of intervention trials (for lipid markers) and prospective cohort studies (for CVD outcomes).
PubMed 26109578 · doi:10.3945/ajcn.114.100305
What was done
Investigators conducted a systematic review and random-effects meta-analysis of studies published through December 2013 evaluating the effects of dietary cholesterol on cardiovascular disease (CVD) risk and serum lipids in healthy adults. Databases searched were MEDLINE, Cochrane Central, and CAB Abstracts. Forty studies met inclusion criteria: 17 prospective cohorts (19 publications, n = 361,923) and 19 intervention trials (21 publications, n = 632).
What was found
Dietary cholesterol was not statistically significantly associated with coronary artery disease (4 cohorts; no summary RR reported), ischemic stroke (4 cohorts; summary RR: 1.13; 95% CI: 0.99, 1.28), or hemorrhagic stroke (3 cohorts; summary RR: 1.09; 95% CI: 0.79, 1.50). In intervention trials, dietary cholesterol statistically significantly increased: - Serum total cholesterol (17 trials; net change: 11.2 mg/dL; 95% CI: 6.4, 15.9) - Low-density lipoprotein (LDL) cholesterol (14 trials; net change: 6.7 mg/dL; 95% CI: 1.7, 11.7; non-significant when doses exceeded 900 mg/d) - High-density lipoprotein (HDL) cholesterol (13 trials; net change: 3.2 mg/dL; 95% CI: 0.9, 9.7) - LDL to HDL ratio (5 trials; net change: 0.2; 95% CI: 0.0, 0.3) Dietary cholesterol did not statistically significantly alter serum triglycerides or very-low-density lipoprotein concentrations.
Why it matters
This review shows that while dietary cholesterol increases circulating total and LDL cholesterol, prospective observational evidence does not show a statistically significant association with clinical coronary artery disease or stroke risk.
Limits
The included studies were heterogeneous and lacked the methodological rigor to draw definitive conclusions on CVD risk. The intervention trials evaluating serum lipids had small sample sizes (total n = 632 across 19 trials), and clinical CVD outcomes were evaluated exclusively through observational cohort studies subject to residual confounding.
Cited by
- contradicts Dietary cholesterol has no long-term impact on serum cholesterol levels.