There's a lot of news about cholesterol these days, and with good reason. High cholesterol contributes to heart disease, which kills more Americans than all cancers combined.
What is cholesterol?
Cholesterol is a waxy, fatlike substance that your body – mainly the liver – produces. Cholesterol is used to make some hormones, vitamin D and bile acids, which help to digest fat. Cholesterol also is used to build healthy cell membranes (walls) in the brain, nerves, muscles, skin, liver, intestines and heart. It only takes a small amount of cholesterol to meet all these needs. Your body makes enough; you don’t have to get cholesterol in your diet.
Why is a high cholesterol level unhealthy?
Cholesterol causes a problem only when you have too much of it in your blood. Excess cholesterol is deposited in the lining of the arteries, including the arteries that feed your heart muscle. This narrows the area inside the artery, through which blood flows. High blood cholesterol itself does not cause symptoms, so many people are unaware that their cholesterol level is too high.
You should have your cholesterol checked at least every five years, starting at age 20. The most accurate test is a lipoprotein profile, a blood test given after fasting for nine to 12 hours. The test will give you these details:
Your total cholesterol
Your LDL ("bad") cholesterol; this cholesterol is what's deposited in your arteries
Your HDL ("good") cholesterol; this cholesterol helps keeps deposits from building up in your arteries
Your triglycerides; these are another form of fat in your blood
Even without a lipoprotein profile, you can get a rough idea of your cholesterol health if you know your total cholesterol and HDL cholesterol. These levels can be determined through a non-fasting cholesterol test often given at shopping malls or health fairs. If your total cholesterol is 200 mg/dL or more, or if your HDL cholesterol is less than 40 mg/dL, you should ask your doctor about getting a complete lipoprotein profile.
A total cholesterol level of 200 mg/dL to 239 mg/dL is considered borderline high; 240 mg/dL and above is high.
HDL (high-density lipoprotein) cholesterol
An HDL level of less than 40 mg/dL for men and 50 mg/dL for women is low; 60 mg/dL and above is considered optimal. The higher your HDL cholesterol, the better, because it helps protect against heart disease.
LDL (low-density lipoprotein) cholesterol
The National Heart, Lung, and Blood Institute identifies 100 mg/dL as an optimal LDL level. An LDL level of 130 to 159 mg/dL is considered borderline high; 160 mg/dL and above is high to very high. For people with known heart disease, the cholesterol level targets are more stringent; ask your doctor what they are. Having a high level of LDL cholesterol can cause fatty plaque to form along the insides of your artery walls. This makes the arteries narrower and stiffer. Narrower arteries mean less room for blood to flow through – like a partially clogged pipe. This process, called atherosclerosis, develops over a long time. It is especially dangerous if it narrows the vessels to the heart and brain, creating a major risk for heart attack and stroke. Build-up of cholesterol in the arteries of the legs can cause leg and foot pain and trouble walking.
What causes high cholesterol?
Heredity is the main factor determining your cholesterol. Then, depending on your genetic makeup, your diet is next in line as a risk factor for high cholesterol. Foods containing cholesterol, saturated fats or trans-fats all contribute to your total cholesterol pool. People with the right genes to handle cholesterol usually have no problem handling a regular fatty diet. For a large portion of the population, however, a bad diet drives the cholesterol up.
Many foods that come from animals are high in both saturated fat and cholesterol. Some non-animal foods also are high in saturated fat; these include foods made with coconut and palm oils and trans-fats, or hydrogenated vegetable oils like shortening and margarine.