Dependence of the effects of dietary cholesterol and experimental conditions on serum lipids in man. III. The effect on serum cholesterol of removal of eggs from the diet of free-living habitually egg-eating people.

Forty-four healthy free living volunteers were used to study the effect of the removal of eggs from a habitual egg-rich diet. The subjects, recruited by advertising, normally consumed at least 1 egg per day. During the 3-week experimental period they were not allowed to eat any eggs or products containing large amounts of eggs, except cakes and tarts. Elimination of eggs from a habitual egg-rich diet did result in a small but significant decrease in serum cholesterol levels in all subjects. No correlation could be demonstrated between changes in serum cholesterol levels and the age of the subjects and between changes in serum cholesterol levels and the numbers of eggs eaten per week before the experimental period. A significant negative correlation was found between changes in serum cholesterol levels and the Quételet index for obesity and between changes in serum cholesterol levels and the serum cholesterol levels before the experimental period. The results indicate that a very variable response is present in a human population toward dietary cholesterol. More research seems to be necessary to describe and select the population of hyperresponders, the subjects who are more sensitive to changes in dietary cholesterol, and the hyporesponders. The results moreover indicate that effects of dietary changes in a free-living population are much smaller than can be accomplished in populations under controlled conditions.