Cholesterol: The Good, The Bad, and the Ugly
You may have had a cholesterol test, but were unsure of how to interpret the numbers. Maybe have heard someone speak of "bad cholesterol" or "good cholesterol", but still wondered what all this meant. We can define these and also discuss goals for your cholesterol "numbers".
Cholesterol is a waxy substance found in all cells of the body where it is produced to form protective membranes, and it is also essential is building vitamin D, substances to digest food (like bile), and hormones such as testosterone and estrogen. The liver produces about 75 percent of it, and the other cells contribute the rest. In other words, your body creates all the cholesterol you need. Dietary sources are not really needed. In fact, a diet high in saturated fats and trans fats stimulate the liver to make even more cholesterol, and this can be in excess to what is needed. The production of cholesterol is mainly taking place while you are sleeping, and this is why you take cholesterol-lowering medicines at night (Scheve, 2008)
There are two lipoproteins that transport cholesterol through your body. Low density lipoprotein, or LDL, is known as the "bad" cholesterol because it is associated with the build up of plaque that blocks the arteries leading to heart disease, heart attacks and strokes. High density lipoprotein (HDL) is often called the "good" cholesterol. The purpose of HDL is to carry cholesterol back to the liver to be broken down and removed from the body. Therefore, theoretically you want a normal or low LDL and a normal to high HDL for health; with this balance you lower your risk of heart disease (National, 2002) How do you remember which is which? I teach a common way to remember: LDL = bad = lousy, and HDL = good = happy.
Triglycerides are the most common fat in our body, and often reflect the diet we eat. This is because a diet high in baked goods (trans fats), sweets and many carbohydrates raise the triglycerides. A high LDL with a high triglyceride level and a low HDL is a risk factor for cardiometabolic disease including risks for heart attack, strokes and even diabetes (American, 2016).
The total cholesterol is a calculation of each of these components: HDL + LDL + 20 percent of your triglycerides (American, 2016). Depending on your health and risks, goals for totals of each of these are set. For instance, those with diabetes or have had a heart attack or stroke need to keep their levels lower to reduce the risk of mortality or another event. The LDL should be less than 130 for most, less than 100 for those with diabetes, and less than 70 if you already have heart disease. When the HDL is checked, the higher the number the better. Generally over 40 is acceptable, and over 60 is good because it is associated with less risk for heart disease. The triglycerides should be less than 150 (Cleveland, 2013).
The American Heart Association recommends that cholesterol levels are checked at age 20 and then every 5 years, but more frequently if you have a cardiometabolic disorder such as high blood pressure, heart disease, diabetes or have had a stroke. High cholesterol (called hyperlipidemia) is silent. Most do not have any clues that you have high cholesterol, except some people develop small yellow raised mole-like skin lesions around the eyes.
Know your risks, know your numbers, and live a healthy lifestyle that reduces your risks.
American Heart Association (2016). What your cholesterol levels mean, Retrieved from www.heart.org/HEARTORG/Conditions/Cholesterol/AboutCholesterol/What-Your-Cholesterol-Levels-Mean_UCM_305562_Article.jsp#WKuYPYWcFMs on 2/19/17.
Cleveland Clinic News and More (2013). What do cholesterol numbers mean. Retrieved from www.myclevelandclinic.org/health/articles/what-do-cholesterol-numbers-mean on 2/20/17.
National Heart, Lung and Blood Institute (2002). What is cholesterol. Retrieved from https://www.nhlbi.nih.gov/health/health-topics/topics/hbcon 2/19/17.
Scheve, T. (2008). What's the difference between LDL and HDL cholesterol? http://health.howstuffworks.com/diseases-conditions/cardiovascular/cholesterol/difference-between-ldl-and-hdl-cholesterol1.htm. Reprinted Feb. 2017. Retrieved on 2/19/17