Cholesterol, a fatty wax-like compound that the body uses to function, is implicated in instances of heart disease. The body naturally produces cholesterol in the liver, which it uses for certain physiological needs, most notably, the production of hormones and to metabolize vitamins. Coupled with the amount of cholesterol a person ingests in his or her diet, the body can become overwhelmed by the volume, and at this point, the cholesterol tends to become deposited on the walls in the arteries, forming plaques. Plaques cause narrowing and blockage in the arteries, which leads to the signs and symptoms, originating in the part of the body with plaques, of increased cholesterol and heart disease.
The relationship between cholesterol and heart disease can be seen in one of the most serious forms of heart disease, coronary heart disease (CHD), which is present when plaques on the artery walls significantly inhibit the supply of nutrients and oxygen to the heart muscle. Like all muscles, the heart muscle needs a constant supply of oxygen and nutrient-dense blood to remain biologically active, which is exclusively carried to the heart by the coronary arteries. The major symptom of CHD is angina, which is squeezing chest pain. Angina is present when the heart begins to be deprived of these essential compounds; the pain can be compared to the cramping leg pain that is present when an athlete is involved in prolonged aerobic activity.
Cholesterol and heart disease connections can be better understood when the concept of the varied types of cholesterol is understood. As cholesterol is transported into the blood stream, either from the liver or ingested from the diet, it is formed into two different types of cholesterol packages, either low-density lipoproteins (LDL) or high-density lipoproteins (HDL). The cholesterol package that tends to cause serious disease is LDL. The beneficial cholesterol, HDL, is largely made within the body, a reason why doctors often recommend that cholesterol intake from diet is, on a whole, undesirable. A cholesterol test relates the different types of cholesterol as a ratio; a higher LDL proportion is beneficial to the circulatory system.
Blood cholesterol and heart disease levels vary throughout the world. For example, in Japan, where the diet is relatively low in cholesterol, heart disease numbers are low compared to regions that have higher cholesterol intake, like the United States. Other factors that contribute to heart disease in addition to cholesterol levels include heredity, weight, and age.