Dose-Dependent Increases in Liver Cholesterol but Not Plasma Cholesterol from Consumption of One to Five Whole Eggs and No Effects from Egg Whites on Liver or Plasma Cholesterol in Hamsters

The dose-dependent effect of egg consumption on plasma cholesterol in humans remains inconclusive. It is unknown if egg white consumed in a normal amount can reduce plasma cholesterol. We used hamsters as a model to (i) investigate the dose-dependent effect of consuming zero to five whole eggs on plasma total cholesterol (TC) and (ii) examine if egg white, equivalent to one to five eggs, possessed any reducing effects on plasma TC. In experiment 1, hamsters were divided into six groups (n = 8 each) and fed either a control diet or one of five experimental diets supplemented with whole-egg powder equivalent to one to five eggs per 2000 kcal. Results showed that supplementation with one egg increased plasma TC by 25% compared with that of the control (226 +/- 16 versus 282 +/- 56 mg/dL, p < 0.05), whereas supplementation with two to five eggs did not significantly produce any additional effects on plasma cholesterol. However, supplementation with one to five eggs in diets caused a dose-dependent accumulation of cholesterol in the liver from 21.5 +/- 4.4 to 71.3 +/- 7.3 mg/g (p < 0.01). In the second experiment, hamsters were divided into six groups and fed either a high-cholesterol control diet or one of five experimental diets supplemented with egg-white powder from one to five eggs. Results showed that egg-white powder affected neither plasma nor liver cholesterol levels. The egg-white powder did not affect fecal sterol excretion, suggesting it had no effect on cholesterol absorption. It was therefore concluded that consumption of two to five eggs did not significantly produce any additional effects on plasma cholesterol, whereas egg white did not possess a plasma-cholesterol-lowering activity if it was consumed at amounts similar to those in a normal human diet.