Coronary heart disease - Coronary heart disease is caused when the blood vessels to the heart (the coronary arteries) become narrowed by a gradual build-up of fatty material within their walls. This condition is called ‘atherosclerosis’. The fatty substance is called ‘atheroma’.
Atheroma develops when LDL cholesterol is chemically changed (a process known as ‘oxidation’) and is taken up by cells in the coronary artery walls where the narrowing process begins. On the other hand, HDL cholesterol removes cholesterol from the circulation, and appears to protect against coronary heart disease. So, the ratio of HDL to LDL in your body is important. The goal is to have a low level of LDL and a high level of HDL.
The level of LDL cholesterol in the blood tends to rise, and HDL falls, with the amount of saturated fats you eat. On the other hand, unsaturated fats have a good effect as they tend to lower LDL levels. As part of a healthy diet, it is important to eat unsaturated instead of saturated fats, and to reduce the total amount of fat you eat.