What is cholesterol?
Dietary cholesterol is a waxy substance found only in foods of animal origin such as poultry, beef, fish, eggs and dairy products. Fruits and vegetables do not contain cholesterol. Cholesterol is necessary to keep the body functioning normally. The liver manufactures enough cholesterol for normal cell processes such as building cell walls and producing hormones. In children, cholesterol plays an important role in the development of the brain and nervous system.
When cholesterol is combined with fats and proteins for use by your body, it forms particles called lipoproteins. There are two types of lipoproteins.
Low-density lipoproteins (LDL or "bad" cholesterol) are associated with the buildup of excess cholesterol on the walls of the arteries. This buildup (plaque) forms on the inner walls of the arteries, reducing blood flow to the heart and brain.
High-density lipoproteins (HDL or "good" cholesterol) remove excess cholesterol from the bloodstream and carry it to the liver for excretion. HDL prevents the accumulation of cholesterol and other fats along the artery walls.
Why does cholesterol matter?
A number of medical studies have found that a high level of cholesterol is a major factor in developing atherosclerosis, the narrowing of arteries through a buildup of fatty plaque. The typical American diet tends to be high in cholesterol and dietary fat.
People who consume large amounts of cholesterol and saturated fats tend to have higher levels of blood cholesterol, as well as a higher incidence of atherosclerosis. Cholesterol buildup in the arteries is the most common cause of heart disease and stroke and happens so slowly that you may not even be aware of it.
Anyone can have high blood cholesterol; there are no warning signs. The only way to find out about your cholesterol level is to have your health care professional perform a lipoprotein profile test (after a nine-to 12- hour fast), which measures total blood cholesterol, LDL, HDL and triglycerides. The National Cholesterol Education Program (NCEP) has developed a series of recommendations for the evaluation of total blood cholesterol. Total blood cholesterol should be measured at least once every five years in adults age 20 and older.
The following cholesterol guideline recommendations were developed by NCEP:
|Total Blood Cholesterol|
|Desirable||200mg/dL or less|
|Borderline-high||200 to 239mg/dL|
|HDL (Good) Cholesterol|
|LDL (Bad) Cholesterol|
|Optimal||Less than 100mg/dL|
|Normal||Less than 150mg/dL|
|Very High||500mg/dL and above|
*Note: New cholesterol guidelines were adapted by NCEP on May 15, 2001.
How can I lower my cholesterol?
The benefits of lowering blood cholesterol are substantial. According to studies by the National Heart, Lung, and Blood Institute, for every 1 percent lowering in total blood cholesterol, Americans can reduce heart attack risk by 2 percent. For most people, the best way to lower cholesterol is to reduce their intake of saturated fats and to increase physical activity.
Accumulation of moderately intense physical activity (30 minutes or more on most, preferably all, days each week) is recommended for adults. For example, 10 minutes of physical activity three times a day or two fifteen minute sessions will meet the minimum requirements for physical activity.
Activities can include walking, riding a bicycle, gardening or washing the car by hand.
Individuals who are overweight can have high total cholesterol levels and low levels of protective HDL cholesterol; studies show that, as weight rises, HDL levels decline and LDL levels creep gradually upward. Controlling your caloric intake and losing excess weight contributes greatly to reducing blood cholesterol.
Reduce your intake of fats, particularly those saturated fats found in animal sources. No more than 30 percent of total daily calories should come from fat.
Consume a diet rich in fruits and vegetables (these foods include carrots, citrus fruits and broccoli) and whole grains such as whole wheat bread.
For some people, high cholesterol levels may continue despite other lifestyle changes. For these persons, lipid-lowering drugs may be recommended. Your health care provider can help to determine whether this option is best suited for your needs.
You can find out more about blood cholesterol by contacting the following organizations:
Centers for Disease Control and Prevention
National Heart, Lung, and Blood Institute