Understanding Cholesterol: From LDL and HDL to Diet and Medication

Blood tests measure two kinds of cholesterol: LDL (low-density) and HDL (high-density) cholesterol. LDL cholesterol is unhealthy. HDL cholesterol is not. A lipoprotein that surrounds a cholesterol core, HDL cholesterol is believed to benefit the body by:

• Eliminating LDL cholesterol
• Transporting LDL cholesterol to the liver, where it is reprocessed and recycled
• Maintaining the health of blood vessel inner walls (endothelium) and preventing atherosclerosis

Good levels of HDL cholesterol exceed 60 milligrams per deciliter. If your HDL level is below 40 mg/dL, you may be at risk for heart disease. LDL cholesterol levels should remain below 100 milligrams per deciliter. If your doctor finds your LDL cholesterol over 160, you may need to start taking medications to lower your cholesterol.

Triglycerides are a different type of fat found in the bloodstream, the kind that results from unburned calories. Your body converts excess calories into triglycerides and stores them in fat cells. Burning more calories than you consume causes the release of hormones that oxidize triglycerides for energy. When high triglyceride levels combine with high LDL levels, fat deposits start sticking to inner arterial walls, leaving plaque that narrows the arteries and restricts blood flow. The risk of suffering a stroke or heart attack increases significantly when triglyceride and LDL levels are too high. Dietary changes, exercise, and medication can help reduce this risk by removing plaque and opening arteries.  

Bypass surgery, or surgery to redirect blood flow to healthier arteries, is one of the most common surgeries performed to treat atherosclerosis and heart disease. Placement of stents in clogged arteries is not as invasive as bypass surgery and can help restore normal blood flow in and around the heart. A relatively new procedure, transmyocardial revascularization treats people with inoperable heart disease by increasing blood flow to and from the heart. In most cases, patients receiving transmyocardial revascularization have undergone angioplasty or stent placement already but did not respond well to the surgery. Another surgical treatment is a carotid endarterectomy, which scrapes away plaque from the inner carotid arterial wall. The carotid artery is the main supplier of blood to the brain and could cause a stroke if clogged by cholesterol.

Initially many people don't realize how much cholesterol is in certain foods and may be surprised at the contents of what they regularly eat.

• Beef and veal -- from 80 milligrams/cholesterol and up, depending on grade
• Pork and pork by-products -- 85 mg
• Animal organ meat -- from 300 mg and up, organ meat (liver, heart, and brain) is extremely high in cholesterol
• Skinless chicken -- 85 mg
• Lean ground beef -- 80 mg
• an egg contains 200 mg of cholesterol
• 1 teaspoon of butter contains 11 mg
• a cup of whole milk contains 35 mg
• 1 ounce of cheddar cheese contains 30 mg

Cigarettes contain thousands of toxins detrimental to human health. One chemical, acrolein, is readily passed into the bloodstream as the lungs absorb inhaled smoke. Scientists believe acrolein promotes heart disease by interfering with the way the liver metabolizes LDL cholesterol and supports HDL cholesterol levels. Acrolein can be synthesized in a laboratory and is an ingredient in chemical weapons and pesticides. Additionally, smoking seems to increase triglycerides by affecting metabolism and calorie oxidation. Although people who smoke might follow a healthy diet and lifestyle practice, they remain at substantial risk for heart disease.

Fiber is one of the most important nutrients in a diet aimed at lowering cholesterol. Not only will fiber reduce LDL cholesterol, but it also has the ability to coalesce into a gel-like material which reduces absorption of cholesterol and fat by the blood. However, only soluble fiber (not insoluble) benefits high cholesterol levels. While foods containing insoluble fiber are healthy -- nuts, celery, whole grains, and bran fiber--they will not directly influence cholesterol levels as much as soluble fiber. Soluble fiber is in foods containing soy, oatmeal, legumes, strawberries, oat bran, apples, and potatoes.

If your doctor diagnoses you with high cholesterol, you can incorporate these simple cooking practices to reduce cholesterol in your diet:

• Whenever a recipe calls for butter or shortening, replace it with cooking oils such as canola, sunflower or olive oil
• substitute 3/4 cup of oil for one cup of shortening or butter
• Instead of chocolate, use cocoa powder, which is lower in saturated fats -- one square of chocolate equals three tablespoons of cocoa powder plus one to one and a half teaspoons of oil
• Always oven-cook food whenever possible -- bake, roast, or broil the meat
• Remove meat immediately from water if it is boiled or simmered. Leaving it to cool in the water will allow it to reabsorb fat
• Eliminate the fat in stock or soup by chilling it. Once well-cooled, remove the fat that rises to the top.

High cholesterol in children is rare but can happen. Heredity, obesity, and diet are the primary risk factors of high cholesterol in children. Most children under 18 who have one parent suffering high cholesterol are at risk of high LDL/low HDL cholesterol levels. Children with a family history of high cholesterol should have regular blood tests to detect any changes to their levels. The American Academy of Pediatrics urges parents to have their children screened one time for cholesterol when children are between nine and 11 years old, and again at 17.

Doctors prescribe statins to reduce LDL and triglycerides. Statin medications block liver enzyme actions responsible for making cholesterol. Taking statins puts a small number of people at risk for side effects such as muscle inflammation, gastrointestinal issues, and high blood sugar. However, the FDA states the benefits of taking statins to lower cholesterol significantly outweigh the risks.

Doctors only need a blood sample to test your LDL and HDL cholesterol levels. Results generally confirm cholesterol levels within two weeks. If the test generates abnormal numbers, the doctor will likely recommend modifications to diet and exercise. Very elevated levels may prompt the doctor to prescribe medication.