Cholesterol is one of several types of fats (lipids) that play an important role in your body. Cholesterol is a waxy substance found in all cells of body. The body needs it to make hormones, Vitamin D, and substances that aid in digestion. The liver makes all the cholesterol needed for these functions.
For the fat-like cholesterol to travel in the bloodstream, the cholesterol is packaged in molecules called lipoproteins. These small packages are made of fat (lipid) on the inside and proteins on the outside. Two of the lipoproteins that carry cholesterol throughout the body are LDL and HDL. It is important to have healthy levels of both LDL and HDL.
Lifestyle can have an impact on cholesterol level, but genetics influence the amount of cholesterol the liver produces. While some people can control cholesterol with a healthy diet and exercise, others may need to add a medication to this regime.
LDL, HDL, and one fifth of the triglyceride value (see below) makes up the total cholesterol value. A healthy total cholesterol level for people at low risk is less than 200. For individuals with coronary artery disease, diabetes, or with more than two other risk factors total, cholesterol should be less than 180.
The National Cholesterol Education Program recommends all adults over age 20 have their total cholesterol checked. If the cholesterol is less than 200 a routine check with subsequent medical checkups is appropriate. If the cholesterol is greater than 200, LDL, HDL, and triglyceride values should be checked.
A modest reduction in cholesterol is known to decrease risk even in those with seemingly "normal" values. Research has shown that decreasing cholesterol lowers the chance of deaths due to heart disease. In those that have heart disease, lowering cholesterol retards further development of blockages and may even promote regression of some blockages.
Low-density lipoprotein or LDL is the bad cholesterol. LDL is the main constituent in the fatty deposits that can develop in the arteries. Elevated LDL increases the risk of heart disease, stroke, aortic aneurysm, and arteriosclerosis in other arteries of the body.
Lowering LDL by 10 percent results in a 20 percent reduction in future coronary risk. If you have heart disease or plaque in the arteries, lowering LDL can stop further plaque from accumulating and may aid in disease regression (a decrease in plaque). An optimal LDL level is 100 or less; 100 to 129 is near optimal for most people.
If have a history of coronary artery disease, carotid or peripheral arterial disease, aortic aneurysm, diabetes, or two other risk factors LDL must be below 100 to decrease the risk of further disease progression. A more aggressive target of LDL <70 is often used for these patients.
For those at very high risk, for example someone who has a coronary stent and continues to smoke, it is recommended that LDL be lower than 70. Dietary changes can reduce LDL levels an average of 15 percent. Dietary changes have the most effect when initial triglyceride levels are elevated.
High-density lipoprotein (HDL), or good cholesterol, protects the arteries against the formation of fatty deposits. The HDL helps remove unused cholesterol from the body. Heredity plays an important role in determining your HDL level.
A low HDL level is an independent risk factor for heart disease. You can raise HDL slightly by losing excess weight, exercising routinely, and not smoking. If heart disease develops in an individual with optimal LDL but low HDL a medication may be added to target the HDL. Low HDL is a value of 40 or below in men and 50 or below in women. High HDL (greater than 60) is considered protective.
Triglycerides are another form of fat that circulate in the blood. Studies have shown that as the level of triglycerides rise, so does the risk of heart disease. An optimal triglyceride level is 150 or less. A fast of 12 hours and no alcohol for 24 hours is required to get an accurate triglyceride blood value.
Triglyceride level is influenced greatly by lifestyle. If your triglycerides are high you can lower the level by losing excess weight, exercising routinely, and decreasing fat, sugar and simple carbohydrates, and alcohol in your diet. The American Heart Association recommends a diet that is low in saturated fat and simple carbohydrates and contains no trans fat.