Consumption of 1-5 whole eggs dose-dependently increases liver cholesterol but not plasma cholesterol and egg white has no effect on liver and plasma cholesterol in hamsters.

It remains inconclusive regarding the dose-dependent effect of egg consumption on plasma cholesterol in humans. 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 0 to 5 whole eggs on plasma total cholesterol (TC), and (ii) examine if egg white equivalent to 1-5 eggs possessed any reducing effect on plasma TC. In experiment 1, hamsters were divided into 6 groups (n=8 each) and fed either a control diet or five experimental diets supplemented with whole egg powders equivalent to 1 to 5 eggs/2000 kcal. Results showed that supplementation of one egg increased plasma TC by 25% compared with the control (226±16 versus 282±56 mg/dL, p<0.05), while supplementation of 2-5 eggs did not significantly produce additional raising effect on plasma cholesterol. However, supplementation of 1-5 eggs in diets caused a dose-dependent accumulation of cholesterol in liver from 21.5±4.4 to 71.3±7.3 mg/g (p<0.01). In the second experiment, hamsters were divided into 6 groups and fed either a high cholesterol control diet or five experimental diets supplemented with egg white powders from 1-5 eggs. Results showed that egg white powders affected neither plasma nor liver. The egg white powder did not affect fecal sterol excretion, suggesting it had no effect on the cholesterol absorption. It was therefore concluded that consumption of 2-5 eggs did not significantly produce additional raising effect on plasma cholesterol, while egg white did not possess a plasma cholesterol-lowering activity if it was consumed at the amount similar to a normal human diet.