Cholesterol is a waxy,
fat-like
sterol that is naturally produced by the body and also found in animal-derived foods. It is an important structural component of
cell membranes and serves as a precursor for
steroid hormones, bile acids, and vitamin D. The body, particularly the liver, can synthesize the cholesterol it needs, so dietary cholesterol is not considered an
essential nutrient.
In the blood, cholesterol does not dissolve in water and therefore travels within
lipoproteins, such as LDL and HDL. LDL carries cholesterol from the liver to tissues, while HDL helps transport cholesterol back toward the liver.
Cholesterol itself is not the same thing as dietary fat, and it is not an
antioxidant.
From a nutrition perspective, the most important cholesterol problem is chronically elevated LDL cholesterol, because LDL is causally involved in
atherosclerosis. This is why nutrition recommendations generally focus more on reducing LDL and overall cardiovascular risk than on simply reducing dietary cholesterol alone.