Cholesterol and Our Bodies

Cholesterol is a soft waxy substance found in the blood and in all our body’s cells. It is an important part of a healthy body because it is used to form cell membranes, some hormones and is needed for other important functions. However, a high level of cholesterol in the blood also known as hypercholesterolemia is a major factor for coronary heart diseases which eventually leads to heart attacks.

Cholesterol and other fats can not dissolve in the blood. They have to be transported to and from the cells by specialized carriers known as lipoproteins. There are several kinds but the two main ones are the Low-density Lipoproteins (LDL) and the High-density Lipoproteins (HDL).

Low-density lipoprotein is the major cholesterol carrier in the blood. Too much LDL cholesterol circulating in the blood can gradually build up in the walls of the arteries feeding the heart and the brain. Together with other substances it can form plaque, a thick and hard deposit that can clog arteries. This condition is known as atherosclerosis. A clot that forms near this plaque can block the blood flow to that part of the heart muscle and thus cause a heart attack. If a clot blocks the blood flow to the brain a stroke results. A high level of LDL cholesterol, usually 150mg/dL or above reflects in an increased risk of heart disease. If one has a heart disease, the LDL should always be less than 100mg/dL. For this reason LDL cholesterol is called “bad” cholesterol. A lower level of LDL cholesterol reflects a lower risk of heart disease.

On the other hand, about one third of blood cholesterol is carried by HDL. It is believed that HDL cholesterol tends to carry cholesterol away from the arteries and back to the liver, where it passes out from the body. It is also believed that HDL removes excess cholesterol from the plaques and in this way slows their growth. HDL is also known as the ‘good’ cholesterol since higher levels of HDL seems to protect against heart attack, whereas, a lower level of HDL usually less than 40mg/dL in men and less than 50 mg/dL in women indicates a greater risk of heart attack. A lower of ‘good’ cholesterol may also raise stroke risks.

People tend to get cholesterol in two of the following ways. The human body, mainly the liver, produces varying amounts a day. Foods also can contain cholesterol. Foods from animals especially diary products contain it whereas food from plants do not contain cholesterol.

Typically the body makes all the cholesterol it needs, so one doesn't need to consume it. Saturated fatty acids are the main culprit in raising blood cholesterol, which increases risk of heart disease. Trans fats also raise blood cholesterol. But dietary cholesterol also plays a part.

Some of the excess dietary cholesterol is removed from the body through the liver. By keeping the dietary intake of saturated fats low, one can significantly lower their dietary cholesterol intake. Foods high in saturated fat generally contain substantial amounts of dietary cholesterol.

People with severe high blood cholesterol levels may need an even greater reduction. Since cholesterol is in all foods from animal sources, care must be taken to eat no more than six ounces of lean meat, fish and poultry per day and to use fat-free and low-fat dairy products. High-quality proteins from vegetable sources such as legumes are good substitutes for animal sources of protein.

Regular physical activity increases HDL cholesterol in some people. Higher HDL cholesterol is linked with a lower risk of heart disease. Physical activity can also help control weight, diabetes and high blood pressure. Aerobic physical activity raises the heart and breathing rates. Regular physical activity such as brisk walking, jogging and swimming also condition the heart and lungs.

Physical inactivity is a major risk factor for heart disease. Even moderate-intensity activities, if done daily, help reduce the risk.