You’ve probably heard of good and bad lipoproteins in relation to your blood cholesterol. However, both the low-density lipoprotein, or LDL, cholesterol and the high-density lipoprotein, or HDL, cholesterol are essential for cell function. Although LDL is traditionally associated with increasing heart disease risk and HDL is associated with reducing it, the relationship between the two is not straightforward. Many disorders can influence your cholesterol levels, so check with your healthcare professional to find the cause if you have abnormal levels.
Cholesterol has traditionally been deemed the artery-clogger contributing to cardiovascular disease and stroke. However, cholesterol is an essential component of your cell membranes and is the precursor molecule for certain hormones and bile acids. Your liver produces all the cholesterol you need, but your body can also use the cholesterol you get through your diet. Since cholesterol can’t dissolve in your blood plasma, you need lipoproteins to carry it throughout your body. These lipoproteins, which consist of varying amounts of protein, cholesterol, triglycerides and phospholipids, vary in size, density, molecular composition and mobility.
Chylomicrons are the largest, least dense lipoprotein. They transport fat and cholesterol that you eat from your intestinal cells to your liver. Very low-density lipoprotein, or VLDL, molecules contain a high proportion of fat. These molecules travel to different tissues through your bloodstream, where the tissues remove the fat from the VLDL molecule. This converts the VLDL molecule to an intermediate-density lipoprotein, or IDL, and eventually to an LDL molecule. LDL molecules are the major cholesterol transporters throughout your body. HDL molecules pick up excess cholesterol from tissues and transport them to your liver.
Excessively high amounts of LDL in your bloodstream have a tendency to build up on your artery walls, causing blood vessel narrowing that can contribute to heart disease. However, you need some LDL to carry cholesterol to your cells and tissues. According to a 2011 report from Texas A&M University, LDL may also help your muscles repair and build mass in response to weight training. Furthermore, low-quality and high-quality forms of HDL may have different health benefits, according to a 2008 study from the University of Chicago. High levels of the low-quality HDL have been associated with diseases such as rheumatoid arthritis, kidney disease and diabetes and don’t have the same heart-protecting effect as the high-quality HDL.
Eating a healthy high-fiber, limited saturated fat diet, exercising regularly and not smoking are generally the most effective ways to achieve healthy blood cholesterol levels. However, some causes of high cholesterol are due to genetic factors and other diseases that alter your cholesterol balance. Therefore, your cholesterol-regulating treatment plan will likely vary depending on the original cause and should be discussed with your doctor.
- Basic Medical Biochemistry A Clinical Approach 3rd Edition, Matthew Lieberman, Ph.D and Allan D. Marks, M.D
- Science Daily: Some 'Good Cholesterol' Is Actually Bad, Study Shows
- Science Daily: 'Bad' Cholesterol Not As Bad As Some People Think
Gina Battaglia has written professionally since 2006. She served as an assistant editor for the "International Journal of Sports Medicine" and coauthored a paper published in the "Journal of Strength and Conditioning Research." Battaglia completed a Doctor of Philosophy in bioenergetics and exercise science at East Carolina University and a Master of Science in biokinesiology from the University of Southern California.