The Truth Behind The Cholesterol Myth
Cholesterol is associated in most people’s minds with heart attack and stroke, but it is an important part of the cell membrane, and of the sheath that surrounds nerve fibers and allows them to conduct electricity.
Cholesterol is also necessary for the production of the adrenal gland hormones cortisol and aldosterone, and of the sex hormones estrogen and testosterone. It is made into bile in the liver and may protect other cells as an antioxidant.
A certain amount of cholesterol is necessary, and it is produced in the liver if it cannot be obtained in the diet.
If cholesterol is taken in from eggs and other foods, production by the liver is dialed back or shut down , so that the total amount of cholesterol obtained from diet and produced by the liver stays about the same(3).
This has led to the suggestion that the recommended limitation of cholesterol intake, from eggs and otherwise, should be reconsidered(4).
HDL Vs. LDL Cholesterol
There is more to cholesterol than just the blood level, however. There are several different subtypes of cholesterol, mainly HDL (high-density lipoprotein) LDL (low-density lipoprotein).
- LDL is the “bad” cholesterol that contributes to atherosclerosis, the deposition of fats and calcium in blood vessel walls that leads to their blockage and results in heart attack and stroke.
- HDL is the “good” cholesterol that helps to remove these deposits and has a protective effect against heart attack and stroke(5).
Several large studies have confirmed that the “good” HDL cholesterol is increased with egg consumption(6), that eggs increase the beneficial effect on “good” cholesterol of a restricted-carbohydrate diet(7) and that whole eggs are more effective in raising “good” cholesterol levels than egg whites(8).