An elderly man became an extreme example of the different responses humans have to cholesterol in their diet by eating 25 eggs a day for at least 15 years with no apparent ill effects, a researcher said Wednesday.

The 88-year-old man, diagnosed as having Alzheimer's disease, maintained a normal blood cholesterol level despite eating soft-boiled eggs throughout the day in addition to his regular diet, said Dr. Fred Kern Jr. of the University of Colorado School of Medicine in Denver.Egg yolks, as well as meat, poultry and dairy products, are the prime sources of cholesterol in the diet, which can contribute to high levels of artery-clogging blood cholesterol.

Cholesterol is a fat-like substance which the body needs to build cells and make certain hormones. But at high levels it can form plaque that narrows arteries and reduces blood flow to the heart, hiking the risk for heart attacks.

While it is thought that 5 percent to 10 percent of the United States population may be genetically predisposed to high cholesterol levels, the man seemed to be an example of the opposite end of the spectrum, Kern said.

"This is probably an extreme example of an individual's ability to adapt to high cholesterol intake," he said. "It has been known for a long time that there is great variability in man's ability to handle cholesterol.

"However, I have never heard of another case of anyone tolerating so much cholesterol over such a long period of time," he added.