Cholesterol is a waxy substance produced and released into the bloodstream by the liver. The body uses cholesterol to form cell membranes, aid in digestion, convert Vitamin D in the skin and develop hormones. Cholesterol is stored inside a waterproof envelope of lipids (fat), along with specific proteins that weave in and out of the envelope 's outer shell. These particles are called lipoproteins1. While cholesterol is something the body needs to operate correctly, having high cholesterol (hyperlipidemia) increases the risk of having a heart attack or stroke.
Who Should Be Screened for High Cholesterol?
All adults age 20+ should have a test for cholesterol at least once every 5 years. It is especially important for adults who meet the following criteria to have their cholesterol levels monitored:
- Those who have been diagnosed with coronary heart disease, suffered a stroke/mini-stroke or have peripheral artery disease (PAD)
- Adults age 40+ (annually)
- People with a family history of cardiovascular disease, stroke, or heart attacks
- Adults with a close family member who has a cholesterol-related condition, such as familial hypercholesterolemia (inherited high cholesterol)
- Those with excess body weight, particularly people with a body mass index (BMI) of 25 or higher (calculate your BMI here)
- Adults with high blood pressure or diabetes
- Adults with medical conditions that can cause increased levels of cholesterol or triglycerides, such as kidney disease, an underactive thyroid gland or an inflamed pancreas (pancreatitis)
How Is High Cholesterol Diagnosed?
High cholesterol is determined with a simple blood test called a lipid panel, and screenings are widely available. Fasting is recommended for 8-10 hours before the blood is drawn, because triglyceride levels can spike after a meal. Another rule is no alcohol for 24 hours before a cholesterol test to get the most accurate reading.
Types of Cholesterol
Bad Cholesterol (LDL – low-density lipoprotein) accounts for 60-70% of the cholesterol in the blood and carries cholesterol from the liver to the cells. If there is too much low-density lipoprotein for the cells to use, this can cause a harmful build-up of cholesterol in the blood.
Good Cholesterol (HDL – high-density lipoprotein) carries cholesterol away from the cells and back to the liver for excretion from the body via the gastrointestinal system. There it is either broken down or passed from the body as a waste product. High-density lipoprotein makes up 20-30% of total cholesterol, and the lower the HDL levels, the greater your risk of heart disease.
Triglycerides are fats used for energy and come from fatty foods. There is usually an association between triglycerides and high cholesterol levels in the blood. Being overweight and drinking too much alcohol can push up triglyceride levels.
Understanding Cholesterol Numbers
The lipid panel report delivers four numbers, and desirable levels of each are in the chart at right. The optimal total cholesterol target is less than 200 mg/dL with a good cholesterol level (HDL) above 60 mg/dL and a bad cholesterol of less than 100 mg/dL. Having high levels of HDL (good) cholesterol does not cancel out high levels of LDL (bad) cholesterol—the most important goal in treatment is to lower the LDL (bad) cholesterol to less than 200 mg/dL, even if the HDL measurement is in the desirable range2.
Generally Desirable Level
under 200 mg/dl
LDL (bad) cholesterol
under 100 mg/dl
HDL (good) cholesterol
over 60 mg/dl
under 150 mg/dl
Measurements are milligrams/deciliter of blood
High Cholesterol and Heart Disease
Heart disease is the #1 killer of both men and women in the U.S. Harmful lifestyle choices are a major cause of heart disease in the U.S. population, primarily fatty, high sodium diets, lack of exercise, and smoking. These lifestyle choices can also lead to high blood pressure and diabetes, both of which increases the risk of heart disease.
As stated above, too much LDL cholesterol in the blood leads to the excess being deposited as plaque in the arteries, which is called atherosclerosis. This plaque buildup in the arteries can narrow, stiffen, and weaken the arteries, making them less effective in delivering blood to the organs, limbs, and brain. As well as being a direct link to heart disease, high cholesterol can lead to strokes, heart attack, and peripheral artery disease.
What Causes High Cholesterol?3
Some people are genetically predisposed to have high cholesterol, but for most people, lifestyle plays a role:
- A diet high in saturated and trans fats found in red meat, full-fat dairy products, and commercially produced food.
- Excess body weight, particularly people with a BMI above 25 (calculate your BMI here).
- Sedentary lifestyle: exercise helps boost the body's HDL, or "good," cholesterol while increasing the size of the particles that make up LDL, or "bad," cholesterol, which makes it less harmful
- Cigarette smoking damages the walls of blood vessels, making them more prone to accumulate fatty deposits
- Age above 50, because as the body ages, its chemistry changes and risk of high cholesterol climbs.
- Diabetes, because high blood sugar not only damages the arteries, it contributes to higher levels of a dangerous cholesterol called very-low-density lipoprotein (VLDL) and lower levels of HDL (good) cholesterol.
Treating High Cholesterol
After a lipid panel test indicates high cholesterol in the blood, the first avenue of treatment will usually involve making some changes to diet and getting an adequate amount of regular exercise. If these changes do not lower cholesterol levels after about three months, a physician may suggest cholesterol-lowering medication, most likely in the statin group of medications. Statins are safe and effective, but some people experience side effects, so be sure to discuss this with your doctor.
A Heart-Healthy Diet
A heart-healthy diet includes lots of fruits and vegetables, whole grains, lean protein (primarily chicken and fish), and small amounts of fat. The best fat sources are fish, nuts, and vegetable oils, and you should avoid saturated fats and trans fats. When selecting meats, poultry, and dairy, choose those that are lean, low fat, or fat-free. Portion control is also important. The average person 's stomach is about the size of a clenched fist, so keep this in mind when loading your plate. If you picture your total daily food consumption as a dinner plate, half of the food should be fruits and vegetables, 15% from whole grains, 15% from lean meat and protein, and no more than 20% from fats.
Avoid or cut down on the following foods, which are rich in saturated fat, and can cause high cholesterol:
- Fatty cuts of meat and meat products, especially red meat
- Butter and vegetable shortening
- Cream, sour cream, and ice cream
- Cheese, particularly hard cheese
- Cakes and cookies
- Coconut oil, coconut cream and palm oil
Using olive oil while cooking can actually lower total cholesterol while preserving the important HDL (good) cholesterol. Studies show that it is possible to stop and even to reverse the buildup of fatty deposits within artery walls.
Moderate exercise is important to overall health, and research is showing that people benefit from even short bursts (20-30 minutes) of activity added to their day. With your doctor's OK, work up to at least 30 minutes of exercise five times a week or vigorous aerobic activity for 20 minutes three times a week.
1 American Heart Association, https://watchlearnlive.heart.org/index.php?moduleSelect=chlscr