Blood cholesterol and dietary cholesterol are two different types of fat. Dietary cholesterol is found in food of animal origin. Blood cholesterol is a waxy substance that occurs naturally in the body. Since cholesterol is not soluble in blood, it is carried around in a protein-coated package called a lipoprotein.
Foods from animal sources that are also high in saturated fats tend to be high in cholesterol. In fact, cholesterol is found only in animal products. These include dairy products, meat, fish, poultry, and fats.
For example: A large egg yolk has about 213 milligrams (mg) of cholesterol.Three and 1/2 ounces of lean ground beef has 78 mg.An 8-ounce glass of 1% fat milk has 10 mg.An 8-ounce glass of nonfat or skim milk has 4 mg.
Some foods, such as nuts, have no cholesterol, even though they are high in fat. Some foods are low in overall fat content but high in cholesterol. For example, a 3-ounce serving of shrimp has 1.5 grams of fat but contains 129 mg of cholesterol. For most people, it is the amount of saturated fat in their diets that raises blood cholesterol levels. However, cholesterol in foods also matters.
A person's blood cholesterol level is influenced by two factors. One is the saturated fat and cholesterol a person eats. The second is how much cholesterol his or her body makes. Cholesterol is made in the liver. Cholesterol is a part of every cell in the body and has some valuable body functions. It is used to make certain hormones and bile, which is needed for digestion of fat.
Sunlight can help a substance containing cholesterol in the skin change to vitamin D. The body produces all the cholesterol it needs. When too much cholesterol is consumed, the body cannot get rid of the excess. Cholesterol can build up on the insides of blood vessel walls. This results in atherosclerosis, or hardening of the arteries.
LDL cholesterol is the main source of buildup on the blood vessel walls. HDL, by contrast, carries cholesterol back to the liver and can prevent buildup on the blood vessel walls.
Cholesterol is a significant factor in the development of coronary heart disease (CHD).
Risk factors and risk equivalents
The higher a person's LDL level and the more risk factors a person has, the greater the chance of developing CHD. People who already have CHD and those who have certain conditions called CHD "risk equivalents" are at the greatest risk of having a major heart-related problem. If a person has CHD risk equivalents, it means that he or she has the same level of risk for a major heart-related problem as someone who already has CHD. These conditions include: diabetesother clinical signs of atherosclerosis, such as peripheral arterial disease,abdominal aortic aneurysm, or certain types of carotid artery diseasethe presence of multiple risk factors (listed below) that give the person a greater than 20% chance of developing CHD within 10 years
A person's risk of developing CHD within 10 years is determined by using information from the Framingham Heart Study. This 10-year risk is calculated from a formula that takes the following into account: agecigarette smokingHDL cholesterolsystolic blood pressure, which is the top number on a blood pressure readingtotal cholesteroltreatment for high blood pressure
A blood lipid test will provide information about a person's: HDL (high-density lipoprotein) cholesterolLDL (low-density lipoprotein) cholesteroltotal cholesteroltriglycerides
The National Heart, Lung, and Blood Institute has set the following guidelines for blood cholesterol levels:
Total cholesterol: desirable range is less than 200 milligrams per deciliter or mg/dLborderline high is 200 to 239 mg/dLhigh cholesterol is 240 mg/dL or greater
LDL results in healthy adults are evaluated as follows: optimal is less than 100 milligrams per deciliter, or mg/dLnear optimal/above optimal is 100 to 129 mg/dLborderline high is 130 to 159 mg/dLhigh is 160 to 189 mg/dLvery high is 190 mg/dL or greater
If an individual has certain other risk factors, LDL cholesterol guidelines goals are stricter. LDL goals for these groups are as follows: less than 100 mg/dL for people with CAD or CAD risk equivalentsless than 130 mg/dL for individuals with two or more risk factorsless than 160 mg/dL for people with 0 to 1 risk factor
A low HDL level is less than 40 milligrams per deciliter, or mg/dL. Low HDL increases a person's risk for CHD. A high HDL is 60 mg/dL or above. High HDL lowers the risk of CHD.
Therapeutic lifestyle changes
The treatment of high blood cholesterol focuses on reduction of LDL cholesterol to the optimal level, whenever possible. LDL can be lowered with therapeutic lifestyle changes or TLC. Medicines may be necessary in addition to TLC for some people. Therapeutic lifestyle changes include regular physical activity and weight management. TLC also includes the following dietary guidelines: 20 to 30 grams of total fiber per day, including 10 to 25 grams of soluble fiber. Soluble fiber is found in oat bran, oatmeal, rice bran, and barley. It is also found in beans, peas, citrus fruits, strawberries, and apple pulp.saturated fat less than 7% of daily caloriespolyunsaturated fat less than 10% of daily caloriesmonounsaturated fat up to 20% of daily caloriestotal fat 25% to 35% of daily caloriescarbohydrates 50% to 60% of daily caloriesprotein about 15% of daily caloriescholesterol less than 200 mg per daysodium limited to 2,400 milligrams a day
TLC guidelines also recommend 2 grams of plant sterols or stanols a day. These are found in enriched food products such as spreads that lower cholesterol.
Putting these recommendations into practice includes: becoming physically active on most daysboiling, baking, broiling, roasting, poaching, steaming sautéing, stir-frying, or microwaving food itemschoosing to eat five or more servings of fruits and vegetables each dayeating no more than 6 ounces of cooked lean meat, fish, or skinless poultry per dayeating six or more servings of breads, cereals, grains, pasta, or dried beans each dayincluding two servings of baked or grilled fish every week. Select fish high in omega-3 fatty acids. Good choices include albacore tuna, salmon, mackerel, lake trout, herring, and sardines.incorporating pasta, rice, beans, and vegetables into mealslimiting the intake of fats to no more than 5 to 8 teaspoons per day. It's helpful to select margarines or vegetable oils that list liquid vegetable oil as the first ingredient. They should contain no more than 2 grams of saturated fat per tablespoon. Good choices include canola, corn, olive, safflower, sesame, soybean, and sunflower oils. Other good choices include almond, avocado, and hazelnut oils. Liquid or tub margarines are better choices than stick margarine. limiting intake of liver, brains, chitterlings, kidneys, heart, and other organ meatsreplacing meat with cooked beans, peas or lentils, peanut butter, or soy products such as tofuselecting dairy products with 1% or less fattrimming all fat from meat products before cooking and removing poultry skin. All fat should be removed after browning meat. Fat can also be skimmed off the top of refrigerated soups and stews.
If a person is not able to lower blood cholesterol levels enough with lifestyle changes, the healthcare professional may suggest medicine that lowers cholesterol.
The FDA has approved health claims for soy products. These plant products can lower cholesterol levels. Diets high in soy products have been shown to reduce LDL cholesterol levels in people with an LDL level above 200 mg/dL when they are substituted for foods high in fat and cholesterol. The soy products can lower LDL cholesterol if the person follows these guidelines: eats a total of 25 grams of soy protein a dayfollows recommended dietary guidelinesmanages weightreplaces saturated fat and cholesterol foods with soy productsstays physically active
Duyff, R., MS, RD, CFCS. (1996). The American Dietetic Association's Complete Food&Nutrition Guide. Minnesota: Chronimed Publishing.