Low-density lipoprotein molecules, or LDL, carry the majority of cholesterol in the blood. LDL is considered the "bad" cholesterol because high levels of LDL correlate with increased risk for heart disease. The American Heart Association says that the level of LDL predicts the risk of heart disease better than does the total level of cholesterol.
Recommendations
According to the American Heart Association, the "optimal" level of LDL is less than 100 mg/dL, and levels ranging from 100 to 129 remain in the healthy range. Levels of 130 to 159 mg/dL of LDL are considered "borderline high," while LDL over 190 mg/dL is very high. The average level of LDL in American adults is 115 mg/dL. The American Heart Association stresses that its recommended levels of LDL are guidelines only, and that individuals need to work with their doctors to achieve a personal healthy level of LDL.
Effects
With high levels of LDL, cholesterol molecules build up on the insides of blood vessels. Combined with other factors, the deposited cholesterol forms plaques or hard, thick clumps that narrow the blood vessels and decrease their flexibility, a condition called atherosclerosis. Plaques make the heart work harder and increase blood pressure, setting the stage for a heart attack or stroke.
Sources
The body naturally makes a certain level of LDL. An individual's genetic background strongly influences his particular "set-point" for production of LDL. Diet also plays an important role. Eating saturated fats and trans fats increases LDL levels, as does eating foods high in cholesterol. Red meats and dairy products tend to be high in saturated fats while commercial cookies and cakes are high in trans fats. Eggs and whole milk are high in cholesterol.
Reduction
Some people can significantly improve their LDL levels by carefully choosing the foods they eat. To lower LDL levels, MayoClinic.com recommends fiber-rich foods like fruits and vegetables, or fish and nuts that provide high levels of omega-3 fatty acids. Losing weight also reduces LDL levels. However, people with a genetic predisposition to high LDL production often cannot control their LDL levels simply by altering their diets.
Medication
MayoClinic.com lists four classes of drugs that can decrease LDL levels. These include statins like lovastatin, bile acid binders like colesevelam, drugs that inhibit cholesterol absorption like ezetimibe, and niacin, which also increases HDL, the "good" cholesterol. Some medications combine two of these classes into one drug. All of these medications have potential side effects and their effectiveness varies among individuals, so patients might need to try several medications before achieving good control of their LDL levels.
