there is evidence to show that the higher you blood cholesterol level the greater you risk of coronary heart disease.
cholesterol is not soluble in water, so in order to be transported in blood it comobined with proteins to form lipoproteins.
low density lipoproteins
low density lipoproteins (LDL's) the main cholesterol carrier in the blood.
to form LDL's triglycerides (from saturated fats) in out diet combine with cholesterol and protein
LDL's circulate in our bloodstream and bind to receptor sites on cell membranes before being taken up by the cells.
excess LDL's in our blood overload these cell membranes, resulting in high blood cholesterol levels.
saturated fats may reduce the activity of LDL's meaning less LDL's are taken out of the blood stream, also meaning higher blood cholesterol levels.
this cholesterol may be deposited in artery walls forming atheromas.
High density lipoproteins
HDL's have a higher percentage of protein compared with LDL's, hence their higher density.
HDL's are formed when triglycerides ( from unsaturated fats ) combine with cholesterol and protein.
HDL's transport cholesterol from body tissues to the liver where it is broken down.
this lower blood cholesterol levels and helps to remove the fatty plaques of atherosclerosis.
monounsaturated fats are thought to help the removal of LDL's from blood.
polyunsaturated fats are thought to increase LDL's activity receptor sites so the LDL's are actively removed from the blood.
LDL's are associated with the formation of Atherosclerosis plaques whereas HDL's reduce blood cholesterol deposition.
therefore its desired to maintain a higher level of HDL's. and less LDL's