Different types of lipoproteins have varied significance on cardiovascular disease. Low-density lipoproteins (LDL) are carriers of cholesterol. Excess cholesterol becomes deposited in blood vessel walls. The blood vessels are narrowed as a result and blood flow becomes compromised. When LDL is oxidised (combined with oxygen) or glycated (bound to glucose), the structure is altered. Altered LDL acts as a direct irritant to the vessel wall causing inflammation. Eventually the inflammatory damage to the blood vessels cannot be repaired. High-density lipoproteins (HDL) have a protective role in cardiovascular disease. HDL takes up cholesterol in the circulation and carries it to the liver where it is broken down. HDL is associated with an enzyme paraoxonase. The enzyme is thought to have an important role in preventing LDL from oxidation and glycation thus reducing its ability to be inflammatory. Therefore too much LDL is harmful to the body but high levels of HDL are advantageous. Dru