by Leslie Eldeiry, M.D., Harvard Clinical Instructor ~ Endocrinologist ~ Internist
Elevated cholesterol, and LDL cholesterol in particular, is one important risk factor for heart disease. An individual may inherit a tendency for high cholesterol (or hyperlipidemia) from his or her parents or grandparents. In addition, lifestyle factors, including diet and exercise habits, other health conditions, and certain medications, can influence cholesterol levels.
LDL, which stands for low density lipoprotein, is also called ‘bad cholesterol’. LDL contributes to plaque formation (hardening of arteries), and is therefore an important risk factor for heart disease, stroke, and peripheral vascular disease. HDL, or high density lipoprotein, is termed ‘good cholesterol’. HDL transports LDL away from blood vessels and back to the liver, therefore high levels of this lipid are considered an important protective factor against heart disease. A third type of blood lipid, triglycerides, which are stored in fat cells and released for energy, are a secondary risk factor for cardiovascular disease.
Some individuals who have very high LDL levels or low HDL levels on the basis of genetic factors may require medication treatment to improve their cholesterol levels. This is especially true if they have other risk factors for cardiovascular disease, such as high blood pressure (hypertension), or diabetes. Age, gender, family history of heart disease, and smoking also determine a person’s cardiovascular risk.
There are currently several available effective medications that are prescribed to lower LDL, but a group of medications called ‘statins’ are the first line option for this purpose. This is because they’ve been proven in large clinical trials to prevent and treat cardiovascular disease in those who are at risk. These drugs work by lowering the production of LDL by the liver, stabilizing plaques (hardening of the arteries) inside blood vessels, reducing inflammation, and clot formation. They are occasionally associated with important side effects, such as muscle ache and liver injury.
Few medication options are currently available and effective for raising HDL. However, both aerobic exercise and strength training can raise good cholesterol levels and also lower triglycerides. This is one more reason to get moving, and often! A group of medications called ‘fibrates’ are prescribed to some patients with very high triglyceride levels.
While medications can help improve lipid levels, dietary modification is a critical mainstay of managing this problem. Specifically, dietary saturated and trans fat reduction is an important intervention you can make to lower both your LDL and triglyceride levels. Saturated and trans fats are found in red meat, whole-fat dairy, such as butter, whole milk, and cream, fried foods, and packaged goods, such as boxed crackers, cookies/dessert, and frozen foods. Read food nutrition labels often to learn how much saturated and trans fats (also called hydrogenated and partially hydrogenated oils) are contained in the foods you eat. In addition, triglyceride levels are influenced by simple sugar (carbohydrate) intake, so reduce your intake of alcohol, sugared sodas, juice, and sweets to help lower this type of blood lipid.
So called ‘good fats’ are contained in oily fish, such as sardines and mackerel, olive and canola oils, nuts, seeds and avocado, so include plenty of these foods in your diet to help maintain healthy cholesterol levels. Finally, foods that are high in fiber, such as oats, beans, whole grains, fruits and vegetables, can help lower cholesterol levels.
The American Heart Association regularly publishes guidelines for screening and treatment of high cholesterol and is a good resource for more information about this subject.