Cholesterol is a waxy substance that your body forms and maintains in every cell of your body. Cholesterol helps your body to produce hormones and digestive enzymes, and to convert sunlight into vitamin D. You also consume cholesterol in some of the foods you eat. Cholesterol does not dissolve in the blood; lipoproteins carry cholesterol through your bloodstream to all the cells in your body. Lipoproteins are clusters with proteins on the outside and fats in the center. Your body carries both high-density lipoproteins, or HDL, and low-density lipoproteins, or LDL. LDL is referred to as "bad cholesterol" and HDL is referred to as "good cholesterol."
High LDL
When doctors suggest you lower your cholesterol, they mean lower your LDL, or your bad cholesterol. LDL causes plaque to develop on your vascular walls, which leads to atherosclerosis, blood clots, heart disease and stroke. Eating foods that contain high levels of cholesterol increases your risk of developing high cholesterol and its associated diseases.
Atherosclerosis
Plaque, which consists of cholesterol, fats, calcium, toxins and other substances, forms along the inside of arterial walls. Plaque hardens and leaves less space for blood to flow freely. This condition, called atherosclerosis, can develop and impede the flow of blood in any area of your body. The resulting tissue damage can cause numerous debilitating medical conditions. High LDL is a primary controllable risk factor for developing atherosclerosis.
Heart Disease
Atherosclerosis that develops in your coronary arteries keeps blood--and oxygen--from reaching your heart. Without oxygen to nourish the cells, heart tissue dies, which results in coronary heart disease, or CHD. Plaque that completely blocks blood flow to the heart can cause a heart attack. According to the National Heart Lung and Blood Institute, CHD is the leading cause of death in the United States for both men and women.
Stroke
Atherosclerosis that develops in the arteries in your neck can keep blood from reaching your brain and can lead to a stroke. According to the National Stroke Association, high levels of LDL and triglyceride, another blood lipid, increases risk of ischemic stroke. Ischemic stroke occurs when brain tissue dies because of inadequate blood supply to the affected part of the brain.
Peripheral Arterial Disease
When high LDL levels cause plaque to build up in your arms, legs and pelvis, you can develop a condition called peripheral arterial disease, or PAD. As blood flow slows, PAD can create pain, numbness and infections of the oxygen-deprived areas of your body. If a clot forms in your legs, you may experience muscle cramps and walking difficulties.
High HDL
Whereas high LDL leads to atherosclerosis, coronary heart disease, stroke and PAD, high HDL prevents these conditions from developing. Medical and media focus remains on lowering LDL to protect against debilitating and fatal diseases, but according to a study published in PubMed.gov, low HDL levels is also a risk factor for heart disease and stroke deaths. While continuing to take measures to lower LDL, you should also actively strive to raise your HDL levels.
References
- National Heart Lung and Blood Institute: High Blood Cholesterol
- National Heart Lung and Blood Institute: Atherosclerosis
- National Stroke Association: Cholesterol and Stroke
- PubMed.gov: High-density vs low-density lipoprotein cholesterol as the risk factor for coronary artery disease and stroke in old age.
- Health.com: Atherosclerosis and Peripheral Artery Disease of the Legs
