Do You Enjoy Eating Eggs?

The major metabolic product of cholesterol is bile acids. The disposal of bile acids by secretion into bile is one of several factors that serve to maintain normal blood cholesterol concentrations, as was demonstrated in an elderly man with a compulsion to eat eggs.

The subject of this case was an 88-year-old man living alone in a retirement community. He was healthy except for having Alzheimer's disease. He also had a compulsive disorder which led him to consume, in addition to regular meals, 25 soft-boiled eggs every day. Remarkably, there was good evidence from several sources that this egg-eating behavior had been going on for at least 15 years.

The patient's medical records documented numerous serum cholesterol measurements within the normal range. A number of metabolic studies indicated that the patient had several compensatory mechanisms in place which enabled him to maintain normal blood cholesterol concentrations in the face of longstanding and massive cholesterol intake:

• Marked reduction in cholesterol absorption - the mechanism for this effect is not known
• Greatly increased synthesis of bile acids - the patient synthesized roughly twice the mass of bile acids as control subjects
• Reduced endogenous cholestrol synthesis

The authors indicated that it would have been interesting to study this patient on a low-cholesterol diet, but that his behavioral disorder prevented it.

Reference

• Kern F: Normal plasma cholesterol in an 88-year-old who eats 25 eggs a day. New Eng J Med 324:986, 1991.