A low cholesterol diet is a diet designed to reduce the amount of cholesterol circulating in the blood.
Cholesterol levels .
|LDL Cholesterol (bad)|
|HDL Cholesterol (good)|
source: National Heart, Lung and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services.
(Illustration by GGS Information Services/Thomson Gale.)
No single person originated the low cholesterol diet. However, the American Heart Association has been a major developer of this diet. The National Cholesterol Education Program organized by the National Heart, Lung, and Blood Institute monitors research and new developments in cholesterol control, including new approaches to low cholesterol dieting.
The low cholesterol diet is designed to lower an individual’s cholesterol level. Cholesterol is a waxy substance made by the liver and also acquired through diet. Cholesterol does not dissolve in blood. Instead it moves through the circulatory system in combination with carrier substances called lipoproteins. There are two types of carrier-cholesterol combinations, low-density lipoprotein (LDL) or “bad” cholesterol and high-density lipoprotein or “good” cholesterol.
LDL picks up cholesterol in the liver and carries it through the circulatory system. Most of the cholesterol in the body is LDL cholesterol. When too much LDL cholesterol is present, it begins to drop out of the blood and stick to the walls of the arteries. The arteries are blood vessels carrying blood away from the heart to other organs in the body. The coronary arteries are special arteries that supply blood to the heart. The sticky material on the artery walls is called cholesterol plaque. (It is different from dental plaque that accumulates on teeth.) Plaque can reduce the amount of blood flowing through the arteries and encourage blood clots to form. A heart attack occurs if the
Dietary fiber —also known as roughage or bulk. Insoluble fiber moves through the digestive system almost undigested and gives bulk to stools. Soluble fiber dissolves in water and helps keep stools soft.
Fatty acids —complex molecules found in fats and oils. Essential fatty acids are fatty acids that the body needs but cannot synthesize. Essential fatty acids are made by plants and must be present in the diet to maintain health.
Hormone —a chemical messenger that is produced by one type of cell and travels through the bloodstream to change the metabolism of a different type of cell.
Steroid —A family of compounds that share a similar chemical structure. This family includes the estrogen and testosterone, vitamin D, cholesterol, and the drugs cortisone and prendisone.
coronary arteries are blocked. A stroke occurs if arteries carrying blood to the brain are blocked.
Researchers believe that HDL works opposite LDL. HDL picks up cholesterol off the walls of the arteries and takes it back to the liver where it can be broken down and removed. This helps to keep the blood vessels open. Cholesterol can be measured by a simple blood test. To reduce the risk of cardiovascular disease, adults should keep their LDL cholesterol below 160 mg/ dL and their HDL cholesterol above 40 mg/dL.
Cholesterol is a necessary and important part of cell membranes. It also is converted into some types of steroid (sex) hormones. Cholesterol comes from two sources. The liver makes all the cholesterol the body needs from other nutrients. However, other animals also make cholesterol. When humans eat animal products, they take in more cholesterol. Cholesterol is found only in foods from animals, never in plant foods. The foods highest in cholesterol are organ meats such as liver, egg yolk (but not egg whites), whole-fat dairy products (butter, ice cream, whole milk), and marbled red meat. To reduce the risk of cardiovascular disease, adults should keep their consumption of cholesterol below 300 mg daily. In 2007, the average American man ate 337 mg of cholesterol daily and the average woman ate 217 mg.
Cholesterol and fats
There are three types of fats in food. Saturated fats are animal fats such as butter, the fats in milk and cream, bacon fat, the fat under the skin of chickens, lard, or the fat a piece of prime rib of beef. These fats are usually solid at room temperature and they are considered “bad” fats because they raise LDL cholesterol.
Unsaturated fats can be monounsaturated or polyunsaturated (This refers to one aspect of their chemical structure.) Monounsaturated fats are “good” fats that help lower cholesterol levels. Olive oil, canola oil, and peanut oil are high in monounsaturated fats. Corn oil, soybean oil, safflower oil, and sunflower oil are high in polyunsaturated fats. Polyunsaturated fats are not bad, they just are not as good as monounsaturated fats. Fish oils that are high in omega-3 fatty acids are polyunsaturated and are very beneficial in preventing heart disease.
Trans fat is made by a manufacturing process that creates hydrogenated or partially hydrogenated vegetable oils. Trans fat acts like saturated fat, raising the level of LDL cholesterol. It is found in some margarines and in many commercially baked and fried foods. Dietary Guidelines for Americans 2005 recommends that no more than 30% of an individual’s daily calories should come from fat, no more than 10% of calories should come from saturated fat, and people should consume as little trans fat as possible.
People who need to reduce their cholesterol level can get help by reading food labels. Food labels are required to list in the nutrition information panel nutrition facts that include calories, calories from fat, total fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrates, dietary fiber, sugars, protein, vitamin A, vitamin C, calcium, and iron In addition, the following words have specific legal meanings on food labels.
- Cholesterol-free: Less than 2 mg of cholesterol and 2 g of saturated fat per serving
- Low cholesterol: no more than 20 mg of cholesterol and 2 grams of saturated fat per serving
The home cook can also reduce cholesterol in the diet in the following ways:
- Choose lean cuts of meat. Select USDA graded cuts of beef and lamb marked Choice and Select. These cuts are leaner and less expensive than Prime
- Bake or broil meats on a rack set in a pan, so that the fat can drip off
- Refrigerate homemade soups and stews, then skim the solidified fat off the top before serving
- If using canned soup or broth that contains fat, put the can in the refrigerator for a few hours, and skim the solid fat off the top before heating
- Try cooking with olive or canola oil rather than corn oil
To reduce cholesterol in meals when eating out:
- Order menu items that have the Heart Healthy stamp.
- Choose items that are broiled, roasted or baked
Avoid fried foods.
- Select fish or chicken instead of beef or pork
- Use margarine instead of butter on food
- Ask for salad dressing, sauces, and gravy on the side
- Order non-fat or 1% milk
In addition to reducing fats, increasing soluble dietary fiber that is found in whole grains also helps lower cholesterol. Soluble fiber is found dissolved in water inside plant cells. In the body, it lowers LDL cholesterol. Good sources of soluble fiber include:
- oatmeal and oat bran
- kidney beans,
- Brussels sprouts
Walnuts and almonds are good sources of polyunsaturated fatty acids that help reduce blood cholesterol levels. Fish such as mackerel herring, sardines, lake trout, albacore tuna and salmon, as well as walnuts, flaxseed, canola and soybean oil are all rich in omega-3 fatty acids, These fatty acids help control fats in the blood and reduce blood clotting. Cholesterol-lowering drugs are available if changes in diet fail to control cholesterol levels. However, it is most desirable to control cholesterol through diet rather than medicine, as these drugs potentially have unwanted side effects.
Low cholesterol diets are healthy diets that can are most effective if they become lifetime habits. Low cholesterol diets work by reducing the amount of saturated (animal) fat to drive down LDL cholesterol and using more monounsaturated fats (olive oil, canola oil) and soluble fiber to drive up HDL cholesterol. By controlling fats in the diet, many individuals lose weight.
Low cholesterol diets have the following benefits:
- decreased intake of dietary cholesterol
- decreased intake of saturated fats
QUESTIONS TO ASK THE DOCTOR
- What are my current cholesterol numbers?
- What are my current risk factors for cardiovascular disease?
- Can my whole family go on this diet?
- Do I have any special health concerns that might affect this diet?
- increased soluble fiber in diet
- decreased risk of developing cardiovascular disease
Anyone over age two can safely follow a low cholesterol diet. Children under age two need certain fats for the normal development of the nervous system and should be given whole-milk and whole-milk products.
There are no known risks to following a low cholesterol diet.
The relationship between cholesterol and saturated fat intake and heart health has been documented in many studies. However, in a study of 49,000 women between the ages of 50 and 79 that was published in February 2007 in the Journal of the American Medical Association, women were divided randomly into a group that ate a low-fat diet and another group that had no restrictions and ate the average America diet. Researchers found no significant difference in the rates of heart attack or stroke between the two groups. They concluded that there was no justification in recommending a low-fat diet to the public as protection against heart disease. This study is particularly important because it was large, well-designed, independent (It was funded by the federal government.) and followed women for 8 years. This study has been extended and these women will be followed until 2010.
The American Heart Association has questioned these findings and continues to recommend a diet low in fat (especially animal fats) and low in cholesterol for the prevention of heart disease.
American Heart Association. American Heart Association Low-Fat, Low-Cholesterol Cookbook: Delicious Recipes to Help Lower Your Cholesterol., 3rd ed. New York: Clarkson Potter, 2004.
Kowalski, Robert. The New 8-Week Cholesterol Cure: The Ultimate Program for Preventing Heart Disease New York: HarperCollins, 2002.
Siple, Molly. Low-cholesterol Cookbook for Dummies Indianapolis, IN: Wiley Pub., Inc, 2004.
American Dietetic Association. 120 South Riverside Plaza,.
Suite 2000, Chicago, Illinois 60606-6995. Telephone:
(800) 877-1600. Website: <http://www.eatright.org> American Heart Association. 7272 Greenville Avenue,.
Dallas, TX 75231. Telephone: (800) 242-8721. Website:
American Heart Association. “Make Healthy Food Choices.” 2007. <http://www.americanheart.org/presenter.jhtml?identifier=537>
Griffin, R. Morgan. “The New Low-cholesterol Diet.” WebMD.com September 2005. <http://www.webmd.com/solutions/sc/low-cholesterol-diet/lowering-with-food>
Harvard School of Public Health. “Interpreting News on Diet.” Harvard University, 2007. <http://www.hsph.harvard.edu/nutritionsource/media.html>
Jackson Siegelbaum Gastroenterology. “Low Cholesterol Diet.” 2006 <http://www.gicare.pated/edtot24.htm>
Mayo Clinic Staff. “Cholesterol: The Best Foods to Lower Your Cholesterol and Protect Your Heart.” MayoCli-nic.com, May 10, 2006. <http://www.mayoclinic.com/health/cholesterol/CL00002>
Northwesternutrition “Nutrition Fact Sheet:Dietary Cholesterol.” Northwestern University, September 21, 2006. <http://www.feinberg.northwestern.edu/nutrition/factsheets/cholesterol.html>
National Heart, Lung, and Blood Institute “Your Guide to Lowering your Cholesterol with TLC (Therapeutic Lifestyle Changes).” December 2005. <http://www.nhlbi.nih.gov/health/public/heart/chol/chol_tlc.pdf>
Tish Davidson, A.M.