Here's some good info on this topic.
Improve Your Cholesterol Profile
Not only have studies shown that eggs do not significantly affect cholesterol levels in most individuals, but the latest research suggests that eating whole eggs may actually result in significant improvement in one's blood lipids (cholesterol) profile—even in persons whose cholesterol levels rise when eating cholesterol-rich foods.
In northern Mexico, an area in which the diet contains a high amount of fat because of its reliance on low-cost meat products and tortillas made with hydrogenated oils, coronary artery disease is common. In a study published in the October 2004 issue of the American Journal of Clinical Nutrition,
researchers evaluated the effects of daily consumption of whole eggs on the ratio of LDL (bad) cholesterol to HDL (good) cholesterol, and phenotype (the way an individual's genetic possibilities are actually expressed) in 54 children (8-12 years old) from this region. A month of eating 2 eggs daily, not only did not worsen the children's ratio of LDL:HDL, which remained the same, but the size of their LDL cholesterol increased—a very beneficial change since larger LDL is much less atherogenic (likely to promote atherosclerosis) than the smaller LDL subfractions. Among children who originally had the high risk LDL phenotype B, 15% shifted to the low-risk LDL phenotype A after just one month of eating whole eggs.
The egg is an inexpensive source of high-quality protein (about 6 grams in a large egg) and an important source of riboflavin and selenium., as well as some iron. These attributes should make it one of nature's near-perfect foods, but the egg has one drawback: Its yolk contains about two-thirds of the total suggested daily maximum intake of cholesterol.
When Americans began to be cholesterol-conscious, the egg was one of the first foods they stopped eating: Following a gradual decline since World War II in per capita consumption of fresh eggs, a markedly steeper drop of some 22% occurred between 1980 and 1990.
In the years since cholesterol became a widespread concern, research has shown that saturated fat has a greater effect on blood cholesterol levels than dietary cholesterol does--and eggs are not a major source of saturated fat. A large whole egg contains about 5 grams of total fat, of which less than 2 grams are saturated. (By comparison, a cheeseburger made with extra-lean beef and only 1 ounce of Cheddar cheese has 12 grams of saturated fat.)
As with cholesterol, differences in the way cholesterol content is measured have resulted in new values for eggs: A study performed by the Egg Nutrition Board (whose values were accepted by the USDA) found that by the new measurement methods a large egg contains nearly 25% less cholesterol than previously thought (210 milligrams instead of 275). In response to these findings, the American Heart Association has raised its weekly acceptable egg intake for healthy people from three whole eggs (or egg yolks) to four. Those with elevated cholesterol still need to limit themselves to one whole egg or egg yolk each week.
Egg whites can be used freely: It is the yolk that contains all of the fat and cholesterol (as well as the major concentration of calories, B vitamins, and minerals). The white is almost pure protein--protein that is considered nearly perfect because of its exemplary balance of amino acids. Even if you are very concerned about your consumption of cholesterol, you can still take partial advantage of the egg's culinary usefulness and nutritional value by cooking with egg whites alone.
