What is Cholesterol?
Cholesterol is a steroidal biochemical (or molecule) that enters the body in two ways: it is eaten, and it is made in the body in the liver and other tissues. When cholesterol is ingested, it comes from animal-based foods like eggs, milk, cheese, and meat. It then enters the blood stream during the digestion process and travels through the blood stream attached to lipoproteins (fat protein). The body also produces cholesterol, because it is needed to create hormones, to maintain cell membranes, for bile production, and for other biological processes, such as the formation of vitamin D. However, too much cholesterol in the blood is unhealthy. It can increase the risk of heart disease by joining with other molecules to create a buildup on the artery walls called plaque.
How Does High Cholesterol Cause Heart Disease?
Cholesterol is a major component of the plaque that causes atherosclerosis. Plaque builds up to the point that it narrows the arteries and restricts blood flow to the heart muscle. When the heart muscle is deprived of blood (and the oxygen in the blood), a heart attack occurs. A diet high in cholesterol and saturated fat produces much more cholesterol than the body needs, so the extra cholesterol joins with other molecules to form plaque and is deposited on the arterial walls. An inactive lifestyle, smoking, obesity, age, heredity, and gender also contribute to high levels of cholesterol.
Because high cholesterol produces no symptoms, it is important to know your cholesterol levels and keep them under control. The screening process involves drawing and analyzing your blood after you have fasted for 12 hours. The American Heart Association and National Institutes of Health recommend having a “lipoprotein” panel drawn beginning at age 20. In fact, there is compelling evidence that children are now at risk for having high cholesterol, so testing at younger ages is recommended for some individuals. A fasting lipoprotein panel measures LDL, HDL, total cholesterol, and triglyceride levels. If results are within a healthy range, they should be rechecked every 5 years. If the results are high or abnormal, you will need to develop a treatment plan and follow-up testing schedule with your doctor.
What are Healthy Cholesterol Panel Scores?
- Total blood Cholesterol: less than 200 mg/dL.
- A cholesterol level greater than 240 mg/dL is high, and you are more likely to suffer a heart attack or stroke.
- HDL (high density lipoproteins): greater than 40 mg/dL.
- HDL cholesterol is the “good” cholesterol. HDL cholesterol provides protection against heart attacks and helps decrease “bad” cholesterol. An HDL level that is lower than 40 mg/dL increases the risk for heart disease.
- LDL (low density lipoproteins): less than 100 mg/dL.
- LDL cholesterol slowly builds up on the walls of the arteries leading to the heart and brain. LDL is the “bad” cholesterol because a high level is associated with a high risk of heart disease. In fact, your LDL level is a better determinant of risk than total cholesterol. The lower your LDL level, the lower your risk.
- Triglycerides: less than 150 mg/dL.
- Triglycerides are a type of fat in the blood, and their level is often high when total cholesterol and LDL cholesterol levels are high or when HDL cholesterol levels are low. High triglyceride levels are linked to coronary artery disease and may also be found in patients with untreated diabetes.
High Risk Populations
You are at a high risk of heart attack if:
- You have low HDL cholesterol and high total cholesterol (you are at the highest risk).
- You are a man with an HDL cholesterol level of 37 mg/dL or less (regardless of your total cholesterol level).
- You are a woman with an HDL cholesterol level of 47 mg/dL or les (regardless of your total cholesterol level).
- You are overweight.
- You have diabetes.
Prevent High Cholesterol
Controlling blood cholesterol level is important in reducing the risk of coronary artery disease and stroke. You have no control over some of the factors that affect your cholesterol level, such as age, gender, and heredity. Therefore, it is important to positively influence the risk factors that you can control:
- Eat a low-fat diet that especially avoids saturated fats and trans fats. Reduce saturated fat and cholesterol consumption by eating lean meats, low-fat dairy products, whole grains, fruits, and vegetables. Read nutrition labels and avoid fast food to completely eliminate trans fats.
- Achieve and maintain a healthy weight. Even a 5% to 10% reduction in weight provides health benefits.
- Be physically active. Regular physical activity and exercise lowers LDL cholesterol levels and raises HDL cholesterol levels. Find a variety of activities that you enjoy and do them for at least 30 minutes every day of the week.
- Quit smoking. Smoking reduces HDL cholesterol levels and damages arteries. If you smoke, seek help in quitting.
- Follow the recommendations of your doctor or healthcare provider.
If you have high cholesterol, your doctor may prescribe cholesterol lowering medication. If so, a heart healthy diet and healthy activity levels make the medication work more efficiently. A healthy lifestyle offers protection against many chronic illnesses, including cardiovascular disease.
American Heart Association www.americanheart.org/presenter.jhtml?identifier=1516
Medline Plus www.nlm.nih.gov/medlineplus/cholesterol.html
Minneapolis Heart Foundation www.mplsheartfoundation.org/education/education_riskfactors_highchol.asp