Effect of dietary egg on variability of plasma cholesterol levels and lipoprotein cholesterol.

The effects of dietary cholesterol on plasma cholesterol levels, its distribution among lipoproteins, and apoproteins of high-density lipoprotein subclasses in individuals who did and did not demonstrate response in plasma cholesterol levels were studied in 21 healthy middle-aged men for 3 mo. After consumption of 3 eggs/day in addition to their habitual diets for 28 days, 21 subjects were divided into 8 hyper- and 13 hypo-responders. The average plasma cholesterol level of the 21 subjects was changed from 188 +/- 36 to 199 +/- 36 mg/100 ml over the 28-day classification period. During the same period the mean plasma cholesterol level of the hyper-responders was significantly increased (p less than 0.025) from 170 +/- 41 to 199 +/- 29 mg/100 ml while that of the hypo-responders fell slightly. The addition of six eggs to the daily diet of the hypo-responders did not alter the mean plasma cholesterol level but resulted in a wide difference in response of plasma cholesterol concentration. The 13 hypo-responders were divided into hypo-hyper-responders (n = 6) and hypo-hypo-responders (n = 7) depending upon the degree of change in plasma cholesterol level. The present study illustrated the variabilities of plasma cholesterol level among free-living subjects who demonstrated two-stage thresholds of response to dietary intake of cholesterol.