Dietary cholesterol from eggs increases the ratio of total cholesterol to high-density lipoprotein cholesterol in humans: a meta-analysis

Background: Several epidemiologic studies found no effect of egg consumptio n on the risk of coronary heart disease. It is possible that the adverse ef fect of eggs on LDL-cholesterol is offset by their favorable effect on HDL cholesterol. Objective: The objective was to review the effect of dietary cholesterol on the ratio of total to HDL cholesterol. Design: Studies were identified by MEDLINE and Biological Abstracts searche s (from 1974 to June 1999) and by reviewing reference lists. In addition, w e included data from a more recently published study. Studies were included if they had a crossover or parallel design with a control group, if the ex perimental diets differed only in the amount of dietary cholesterol or numb er of eggs and were fed for greater than or equal to 14 d, and if HDL-chole sterol concentrations were reported. Of the 222 studies identified, 17 stud ies involving 556 subjects met these criteria. Results: The addition of 100 mg dietary cholesterol/d increased the ratio o f total to HDL cholesterol by 0.020 units (95% CI: 0.010, 0.030), total cho lesterol concentrations by 0.056 mmol/L (2.2 mg/dL) (95% CI: 0.046, 0.065 m mol/L; 1.8, 2.5 mg/dL), and HDL-cholesterol concentrations by 0.008 mmol/L (0.3 mg/dL) (95% CI: 0.005, 0.010 mmol/L; 0.2, 0.4 mg/dL). Conclusions: Dietary cholesterol raises the ratio of total to HDL cholester ol and, therefore, adversely affects the cholesterol profile. The advice to limit cholesterol intake by reducing consumption of eggs and other cholest erol-rich foods may therefore still be valid.