September is National Cholesterol Education Month and it seemed fitting to take the time to review the basics of cholesterol as it relates to heart health.
What Is Cholesterol?
Cholesterol is a fatty, waxy substance that comes from two sources: that which is made by the liver, and that which we ingest through dietary intake. The liver makes all that is needed for the human body to function properly (and it doesn’t take much cholesterol at all for our body systems to function), so the amount of dietary cholesterol we need is zero. Dietary cholesterol comes from animal foods; whole plant foods do not contain cholesterol.
What Are Lipids?
Lipids are fat-like substances found throughout the body; cholesterol is a generalized term for certain kinds of lipids. The cholesterol panel that is commonly ordered to check a patient’s cholesterol is more accurately referred to as a lipid panel.
What Is Included in a Lipid Panel?
While there are special, advanced lipid panels that include many different kinds of lipoproteins (forms of lipids that are of particular interest to physicians because of their ability to cause cardiovascular disease), the most common, basic lipid panel measures or calculates the following from a blood sample: total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglycerides.
LDL cholesterol is often called the “bad cholesterol,” because it is directly linked to clogged arteries, blood vessel dysfunction, heart attacks, and strokes. In fact, research has shown that the higher one’s LDL cholesterol level, the higher one’s risk of cardiovascular disease. The rise in cardiovascular risk is directly proportional to rise in LDL.
HDL cholesterol, on the other hand, has often been called the “good cholesterol,” because high levels of HDL cholesterol appear to protect against heart disease, in most cases. However, much remains unknown about HDL cholesterol, and clinical trials that have tried to raise HDL cholesterol by pharmaceutical mechanisms have not borne fruit in terms of preventing cardiovascular disease.
Triglycerides are the main components of fats and oils, and high levels in the bloodstream have been associated with stroke and heart attack. High levels of triglycerides are often found in cases of diabetes, heavy alcohol use, thyroid disorders, obesity, heavy fat and refined-carb intake, and other genetic and metabolic disorders.
When Should Cholesterol Be Checked?
The American Academy of Pediatrics endorses checking cholesterol, particularly LDL cholesterol, levels between the ages of 9 and 11. If there is a family history of a genetic cholesterol disorder such as familial hypercholesterolemia, cholesterol levels should be checked even earlier.
For adults, the American Heart Association recommends that all adults age 20 and older should have their cholesterol levels checked at least once every five years. Those who have cholesterol disorders or high cholesterol will need to have their levels checked more often than that.
It is important to know your cholesterol numbers, as approximately 1 in 500 people has familial hypercholesterolemia (a genetic cholesterol disorder that leads to early heart attack and premature death if left untreated), and most others on a traditional Western-style diet have elevated cholesterol levels that put them at risk of cardiovascular disease. Knowing your numbers is the first step toward taking charge of your heart health!
Yasmine S. Ali, MD, MSCI, FACC, FACP, is President of Nashville Preventive Cardiology, PLLC, in Nashville, TN. She is board-certified in internal medicine and cardiovascular disease, as well as in clinical lipidology and nuclear cardiology. She is a Fellow of the American College of Cardiology and of the American College of Physicians. She graduated from Vanderbilt University School of Medicine in 2001, and has made it her career’s work to follow her passion for preventing cardiovascular disease and improving heart health for as many people as possible. In addition, Dr. Ali is also the Physician Expert for the Obesity site for www.obesity.about.com. Each month she will be contributing an educational piece on preventing cardiovascular disease. To learn more about Dr. Ali, visit www.preventivecardio.com.