Cholesterol is a naturally occurring endogen substance in the body that regulates multiple processes and is normally synthesized in the liver or is digested from different animal foods. Cholesterol cannot be dissolved in blood and in order to transport it within blood special carriers exist. These carriers are called lipoproteins. Different types of lipoproteins exist in the organism according to their density:

• Very low density lipoproteins - newly synthetized carriers that move from the liver to the adipose tissue - considered "bad" in increased concentrations
• Intermediate density lipoproteins - The substances are not usually detectable in blood and are considered "bad"
• Low density lipoproteins which are considered "bad" for the health due to the fact that they build up on the artery walls and may form blood clots dangerous for the human organism. High levels of LDL are one of the first indications of possible heart cardiovascular complications.
• High density lipoproteins on the other hand are considered to be "good" cholesterol carriers due to their ability to carry the excess cholesterol to the liver where in can be eliminated with the bile. HDL also prevents the formation of clots, build up of cholesterol in the vessels. Low levels of HDL may also be the indicator of possible heart disease.