Cholesterol plays an essential role in the formation of cell membranes, some hormones and Vitamin D. However problems occur when there is too much cholesterol in the body. If cholesterol builds up in the arteries, which carry the blood away from the heart, plaques form narrowing the arteries. If the flow of blood is slowed or blocks the arteries, this can lead to atherosclerosis, which leads to chest pain, commonly known as angina. If a plaque ruptures, blood clots are formed which can cause heart attacks or stroke.
Two main lipoproteins (fat and protein complexes) play central roles in the development of plaques and cardiovascular (heart) disease. The two forms are known as HDL (high density lipoprotein) and LDL (low density lipoprotein). LDL cholesterol, considered the ‘bad’ cholesterol, transports cholesterol from the liver to the rest of the body. If there is too much cholesterol in the blood, then it is deposited in the walls of the coronary arteries. HDL cholesterol carries cholesterol from the blood to the liver for removal from the body and hence is called the ‘good’ cholesterol. When the level of LDL cholesterol in the blood is high, and HDL cholesterol is low, there is a greater risk of heart disease. One of the factors which determines the level of blood cholesterol is the amount of cholesterol consumed in the diet.