Definition and Facts About High Cholesterol
High cholesterol levels are due to a variety of factors including heredity, diet, and lifestyle.
- Cholesterol is a waxy, fat-like substance that the body needs to function normally. Cholesterol is used as a building block for many structures as well as other chemicals and hormones that are essential for the body’s activities.
- The body does not need that much cholesterol, and excess amounts can be deposited along the lining of artery walls, decreasing the amount of blood flow to different parts of the body.
- High cholesterol is one of the risk factors that can lead to atherosclerotic cardiovascular disease (ASCVD), including heart attack, TIA, stroke, and peripheral artery disease.
- Examples of foods high in cholesterol include:
- Egg yolks
- Shellfish like shrimp
- Processed meats like bacon
- Baked goods such as pies and cakes made with animal fats like lard and butter
What Is High Cholesterol?
The body uses cholesterol to produce many hormones, vitamin D, and the bile acids that help to digest fat. It takes only a small amount of cholesterol in the blood to meet these needs. If a person has too much cholesterol in the bloodstream, the excess may be deposited along the walls of arteries, including the coronary arteries of the heart, the carotid arteries to the brain, and the arteries that supply blood to the legs and the intestines.
Cholesterol deposits are a component of the plaques that cause narrowing and blockage of the arteries, producing signs and symptoms originating from the particular part of the body that has decreased blood supply.
Who Has High Cholesterol?
- Throughout the world, blood cholesterol levels vary widely. Generally, people who live in countries where blood cholesterol levels are lower, such as Japan, have lower rates of heart disease. Countries with very high cholesterol levels, such as Finland, also have very high rates of coronary heart disease. However, some populations with similar total cholesterol levels have very different heart disease rates, suggesting that other factors also influence the risk for coronary heart disease.
- 71 million American adults (33.5%) have LDL, or "bad" cholesterol
- People of all ages and backgrounds can have high cholesterol.
What Causes High Cholesterol?
High cholesterol levels are due to a variety of factors including heredity, diet, and lifestyle. Less commonly, underlying illnesses affecting the liver, thyroid, or kidney may affect blood cholesterol levels.
- Heredity: Genes may influence how the body metabolizes LDL (bad) cholesterol. Familial hypercholesterolemia is an inherited form of high cholesterol that may lead to early heart disease.
- Weight: Excess weight may modestly increase your LDL (bad) cholesterol level. Losing weight may lower LDL and raise HDL (good) cholesterol levels.
- Physical activity/exercise: Regular physical activity may lower triglycerides and raise HDL cholesterol levels.
- Age and sex: Before menopause, women usually have lower total cholesterol levels than men of the same age. As women and men age, their blood cholesterol levels rise until about 60 to 65 years of age. After about age 50 years, women often have higher total cholesterol levels than men of the same age.
- Alcohol use: Moderate (1-2 drinks daily) alcohol intake increases HDL (good) cholesterol but does not lower LDL (bad) cholesterol. Doctors don't know for certain whether alcohol also reduces the risk of heart disease. Drinking too much alcohol can damage the liver and heart muscle, lead to high blood pressure, and raise triglyceride levels. Because of the risks, alcoholic beverages should not be used as a way to prevent heart disease.
- Mental stress: Several studies have shown that stress raises blood cholesterol levels over the long term. One way that stress may do this is by affecting your habits. For example, when some people are under stress, they console themselves by eating fatty foods. The saturated fat and cholesterol in these foods contribute to higher levels of blood cholesterol.
What Are High Cholesterol Symptoms and Signs?
High cholesterol is a risk factor for other illnesses and by itself does not cause symptoms. Routine screening blood tests may reveal elevate cholesterol levels in the blood.
Whom should have their cholesterol checked and when?
The National Cholesterol Education Program guidelines suggest that everyone aged 20 years and older should have their blood cholesterol level measured at least once every 5 years. It is best to have a blood test called a lipoprotein profile to find out your cholesterol numbers.
Is There a Test for High Cholesterol?
Cholesterol levels in the body are measured by blood testing. In addition to cholesterol and its different types, triglyceride levels can also be included in a lipid (fat) profile.
The commonly measured part of the lipoprotein profile blood test includes:
- Total cholesterol
- High density lipoprotein (HDL)
- Low density lipoprotein (LDL)
What Do High Cholesterol Numbers Mean? Charts
High cholesterol is a risk factor for ASCVD including heart attack, TIA, stroke, and peripheral artery disease. The health-care professional and the patient can use the results to decide whether medications may be helpful in lowering cholesterol levels and decreasing the risk of future illness.
Blood test interpretation
|Less than 200 mg/dL: desirable
|200-239 mg/dL: borderline high risk
|240 and over: high risk
|HDL (high density lipoprotein)
|Less than 40 mg/dL (men), less than 50 mg/dL (women): increased risk of heart disease
|Greater than 60mg/dL: some protection against heart disease
|LDL (low density lipoprotein)
|Less than 100 mg/dL: optimal
|100-129 mg/dL: near optimal/above optimal
|130-159 mg/dL: borderline high
|160- 189 mg/dL: high
|190 mg/dL and above: very high
|Less than n150 mg/dL: normal
|150-199 mg/dL: borderline to high
|Above 500 mg/dL: very high
Is High Cholesterol Dangerous? Risk Factors
High cholesterol is just one of several risk factors for coronary heart disease. A health-care professional will consider a person's overall risk when assessing their cholesterol levels and discussing treatment options.
Risk factors are conditions that increase a person's risk for developing heart disease. Some risk factors can be changed and others cannot. In general, the more risk factors a person has, the greater the chance of developing coronary heart disease. Some risk factors can be controlled; however, some cannot be controlled.
Risk factors that cannot be controlled include:
- Age (45 years or older for men; 55 years or older for women)
- Family history of early heart disease (father or brother affected before age 55 years; mother or sister affected before age 65 years)
Risk factors that can be controlled include:
If a person has high lipoproteins and thus high cholesterol, their doctor will work with them to target their levels with dietary and drug treatment. Depending on a person's risk factors for heart disease, target goals may differ for lowering their LDL cholesterol.
What Are the Diet Guidelines for High Cholesterol?
The National Cholesterol Education Program has created dietary guidelines for high cholesterol.
- NCEP dietary guidelines are:
- Total fat: less than 30% of daily caloric intake
- Saturated fat: less than 7% of daily caloric intake
- Polyunsaturated fat (found in vegetables, nuts, seeds, fish, leafy greens): less than or equal to 10% of daily caloric intake
- Monounsaturated fat: approximately 10%-15% of daily caloric intake
- Cholesterol: less than 200 milligrams per day
- Carbohydrates: 50%-60% of daily caloric intake
- Some people are able to reduce fat and dietary cholesterol with vegetarian diets.
- Stanol esters can be included in the diet and may reduce LDL by about 14%. Products containing stanol esters include margarine substitutes (marketed as brand names Benecol and Take Control).
- People with higher triglycerides may benefit from a diet that is higher in monounsaturated fat and lower in carbohydrates, particularly simple sugars. A common source of monounsaturated fat is olive oil.
What Foods Help Lower Cholesterol Levels?
Foods may lower cholesterol levels in the body through different mechanisms. High fiber foods bind cholesterol and make it difficult to be absorbed. Some plants contain stanols and sterols, which prevent the cholesterol from being absorbed into the bloodstream. Examples of cholesterol-lowering foods include:
- Oats, barley and other whole grains
- Apples, strawberries, grapes
- Citrus fruits
- Fatty fish
- Foods that are manufactured or fortified to contain sterols and stanols, like some orange juices and margarine
What Foods Should You Avoid Because They Raise Cholesterol Levels?
There are some foods that have a tendency to increase cholesterol and should be avoided if possible:
- Egg yolks
- Dairy products including butter and some cheeses, including cream cheese
- Processed meats like bacon
- Baked goods made with animal fats like lard
- Fast foods like hamburgers, French fries, and fried chicken
- Snack foods like microwave popcorn because of their high salt and butter content
- Red meats
What Other Lifestyle Changes Help Lower Cholesterol?
In addition to eating a heart-healthy and cholesterol-lowering diet other lifestyle changes can help lower cholesterol; and therefore, lower the risk of heart attack, stroke
and peripheral artery disease.
- Exercise: 30 minutes a day can raise HDL levels (the good cholesterol). If you are just beginning to exercise start in moderation. If you have underlying medical problems including heart or lung disease, check with your health-care professional for guidance about what exercise program might be best for you.
- Stop smoking: Smoking increases HDL levels, but also by itself decreases the risk of heart attack almost immediately.
- Maintain a healthy weight: Even a little weight loss can help manage cholesterol levels.
- Activity: Although exercise has little effect on LDL, aerobic exercise may improve insulin sensitivity, HDL, and triglyceride levels and may thus reduce the risk of heart disease. People who exercise and control their diet appear to be more successful with long-term lifestyle modifications that improve their heart risk profile.
How Do Statins Work (Treatment)?
Statins lower LDL cholesterol levels more than other types of drug. They lower cholesterol by slowing down the production of cholesterol and by increasing the liver's ability to remove the LDL cholesterol already in the blood.
- Studies using statins have lower LDL cholesterol levels in people taking them. Statins also reduce high triglyceride levels modestly and produce a mild increase in HDL cholesterol.
- Results from statin medications are seen after several weeks. After 6 to 8 weeks, a patient's doctor may recheck blood tests. The second measurement of LDL cholesterol level must be averaged with the first to help adjust medication dosing.
- Statins are well tolerated, and serious side effects are rare. Rarely, widespread muscle breakdown, known as rhabdomyolysis, may occur. The symptoms include diffuse muscle pain, weakness, and dark colored urine. This may signal a medical emergency: if you develop these symptoms, stop taking the statin medication and contact your health care practitioner immediately.
- Other side effects may include an upset stomach, gas, constipation, and abdominal pain or cramps. These symptoms are usually mild to moderate and generally go away as your body adjusts to the medication.
- Monitoring of liver function by blood tests is usually ordered in patients taking statins.
- There are many statin drugs (available by prescription). The choice made by the healthcare professional and patient will depend upon the clinical situation. Examples include:
What Other Medications Treat High Cholesterol?
Bile acid sequestrants: These drugs bind with cholesterol-containing bile acids in the intestines and allow them to be eliminated in the stool. Bile acid sequestrants may lower LDL cholesterol by a significant amount. Bile acid sequestrants are sometimes prescribed with a statin to enhance cholesterol reduction.
- Cholestyramine (Questran, Questran Light), colestipol (Colestid), and colesevelam (WelChol) are the three bile acid sequestrants currently available. These three drugs are available as powders or tablets and are not absorbed from the gastrointestinal tract.
- Bile acid sequestrant powders must be mixed with water or fruit juice and are taken once or twice daily with meals. Tablets must be taken with large amounts of fluids to avoid stomach and intestinal complaints including constipation, bloating, nausea, and gas.
Cholesterol absorption inhibitors: These drugs inhibit cholesterol absorption in the gut and has few, if any, side effects. Cholesterol absorption inhibitors may be rarely associated with tongue swelling (angioedema). Ezetimibe (Zetia) reduces LDL cholesterol by a significant amount. It is probably most useful in people who cannot tolerate taking statins. When used in addition to a statin, ezetimibe is equivalent to doubling or tripling the statin dose.
Nicotinic acid or niacin: Nicotinic acid lowers total cholesterol, LDL cholesterol, and triglyceride levels while raising HDL cholesterol levels.
- There are two types of nicotinic acid: immediate release and extended release.
- The immediate-release form of crystalline niacin is inexpensive and widely accessible without a prescription, but, because of potential side effects, it should not be used for cholesterol lowering without monitoring by a healthcare professional. (Nicotinamide, another form of niacin, does not lower cholesterol levels and should not be used in place of nicotinic acid.)
- A common and troublesome side effect of nicotinic acid is flushing or hot flashes, which are the result of blood vessels dilating. Most people develop a tolerance to flushing, which can sometimes be decreased by taking the drug during or after meals or by the use of aspirin or other similar medications prescribed by your doctor 30 minutes prior to taking niacin. The extended-release form may cause less flushing than the other forms.
- The effect of high blood pressure medicines may also be increased while taking niacin causing blood pressure to potentially drop. A variety of gastrointestinal symptoms, including nausea, indigestion, gas, vomiting, diarrhea, and peptic ulcers have been experienced with the use of nicotinic acid. Other major side effects include liver problems, gout, and high blood sugar.
- Extended-release niacin is often better tolerated than crystalline niacin. However, its liver toxicity (liver damage) is probably greater. The dose of extended-release niacin is usually limited to 2 grams per day.
Fibrates: These cholesterol-lowering drugs are effective in lowering triglycerides.
Side effects of fibrates may include stomach or intestinal discomfort, gallstones, and may affect anticoagulation medication effects in thinning blood.
PCSK9 protein inhibitors: these medications are indicated for certain patients whose LDL levels are not adequately controlled with diet and statins.
- alirocumab (Praluent)
- evolocumab (Repatha)
Is It Possible to Prevent High Cholesterol?
Adoption of a healthier lifestyle, including aerobic exercise and a low-fat diet, should reduce the risk of obesity, high cholesterol, and, ultimately, the risk of coronary heart disease.
- Knowing your cholesterol number is the first step in controlling your levels.
- Set dietary goals based on the guidelines from the National Cholesterol Education Program.
- Aim for daily intake of less than 7% of your calories from saturated fat and less than 200 mg of cholesterol from the food you eat.
- You may eat up to 30% of your calories from total fat, but most should be from unsaturated fat, which doesn't raise cholesterol levels.
- Add more soluble fiber (found in cereal grains, beans, peas, and many fruits and vegetables) and foods that contain plant stanols and sterols (included in certain margarine and salad dressings) to boost your LDL-lowering power. The best way to know what's in the foods you eat is to read the nutrition label.
- Lower cholesterol levels start at the grocery store. Read food labels, and buy foods low in saturated fat and low in cholesterol.
- Work with your healthcare professional to determine whether medication is needed to control high cholesterol.
What Is the Outlook for a Person With High Cholesterol?
- Controlling high cholesterol levels is a lifelong challenge. Regardless of the method of treatment, routine blood tests may be required to monitor cholesterol, HDL, LDL, and triglyceride levels.
- Cholesterol control is useful in reducing the risk of heart attack, stroke, and peripheral artery disease. It is one part of the risk reduction strategy that includes smoking cessation, weight control, blood pressure control, and exercise
Lloyd-Jones DM, et al. "2016 ACC Expert Consensus Decision Pathway on the Role of Non-Statin Therapies for LDL-Cholesterol Lowering in the Management of Atherosclerotic Cardiovascular Disease Risk." Journal of the American College of Cardiology. 68:1. July 2016
Stone NJ, et al. "2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines." Circulation 2014.