From Dr. Fuhrman's book Cholesterol Protection For Life:
Fat is one of the three macronutrients (along with protein and carbohydrate) that supply calories to the body. Fats provide 9 calories per gram, more than twice the number provided by carbohydrates or protein.
Fats provide the "essential" fatty acids, which are not made by the body and must be obtained from food. Fatty acids provide the raw materials that help control blood pressure, blood clotting, inflammation and other important body functions.
Fat is essential for the proper functioning of the body. Healthy skin and hair are maintained by fat. Fat helps in the absorption and transport through the bloodstream of the fat soluble vitamins A, D, E and K. Fats perform vital and valuable role in the body. For example, fats:
- Are a part of all cell membranes.
- Make up part of the material that insulates nerves and increases the efficiency of nerve conduction.
- Make up an integral part of certain hormones that regulate blood pressure, clotting and inflammation.
- Are the major component of brain tissue and are necessary for emotional well being. The energy or calories that one consumes in excess of the body's needs is mainly stored as fat (adipose). Eating too much fat, just like eating too much carbohydrate and too much protein (the three sources of calories), can lead to excessive storage of body fat, weight gain and obesity. Too much fat, as well as too many calories in general contribute to coronary artery disease and other heart-related problems.
Like certain vitamins and minerals, there are also certain fats that are essential to humans. Eliminating fat completely from one's diet can lead to an essential fatty acids deficiency with negative health consequences. Therefore, a heart-healthy diet should aim to include dietary fats in a balance with other nutrients to provide essential fatty acids to meet daily energy needs and other metabolic needs of the body. Emphasis should be placed on minimizing or eliminating saturated fat and trans fat intake.
Some naturally occurring fats are called saturated because all the carbon atoms are single bonds. These fats are solid at room temperature and generally recognized as a significant cause of both heart disease and cancer. Saturated fats are found mainly in meat, fowl, eggs, and dairy. The foods with the most saturated fat are butter, cream, and cheese.
Saturated fat raises your LDL-cholesterol level more than anything else in the diet. Eating too much saturated fat and cholesterol is the main reason for the high number of heart attacks seen in North America and other countries.
These fats are a mix of monounsaturated and polyunsaturated fat. Eating unsaturated fats lowers cholesterol when substituted for saturated fats, but excessive amounts may promote cancer and obesity. Examples of unsaturated fats are the fats in nuts and seeds such as flax seeds, sunflower seeds, macadamia and pistachio nuts, almonds, walnuts, cashews, as well as avocados and olives.
Are fats with more than one double bond in the carbon chain. Like monounsaturated fat, these natural fats are also found in their natural state in raw seeds such as sesame, sunflower as well as in corn and soybeans and are essential for normal body development and function.
Are fats with only one double bond in the carbon chain. They are liquid at room temperature and thought to have health benefits. The supposed health benefits of these fats appear when these fats are used in place of dangerous saturated fats. Monounsaturated fat is found in avocados, olives, almonds, peanuts, and most other nuts.
Hydrogenation is a process of adding hydrogen molecules to unsaturated fats which makes plant oils that are liquid at room temperature, solidify. An example is margarine. These fats are also called TRANS FATS. The hardening of the fat extends its shelf life so that the oil can by used over and over again to fry potatoes in a fast food restaurant or be added to processed foods, such as crackers and cookies. While hydrogenation does not make the fat completely saturated, it creates trans-fatty acids, which act like saturated fats. These fats raise cholesterol and increasing evidence is accumulating demonstrating the harmful nature of these man-made fats and their relation to both cancer and heart disease. Avoid all foods whose ingredients contain partially hydrogenated or hydrogenated oils.
Cholesterol is a waxy fat produced by the body and found in animal foods such as meat, fowl, dairy, and eggs. Eating cholesterol does raise blood cholesterol, but ironically not as much as eating saturated fats and trans fats. The amount of cholesterol in plants is so negligible that you should consider them cholesterol free.
LOW DENSITY LIPOPROTEIN (LDL)
LDL cholesterol is the bad guy that promotes the plaque that leads to blockages and heart attacks. Thus, the more LDL-cholesterol you have in your blood, the greater your risk of heart disease.
HIGH DENSITY LIPOPROTEIN (HDL)
HDL cholesterol is the "good" cholesterol and carries cholesterol back to the liver for removal from the body. So a higher HDL helps keep cholesterol from building up in the walls of the arteries. Individuals with a total cholesterol/HDL ratio above 4 are considered to have an exceptionally high risk of heart disease. So, the higher your HDL-cholesterol, the better. However, those with exceptionally low LDL cholesterol do not have to worry about their HDL level. You don't need the garbage collectors when there is no garbage.
Docosahexaenoic acid (DHA) is a long chain omega 3 fat that is made by the body, but can also be found in algae and fish, such as salmon and sardines. DHA is used in the production of anti-inflammatory mediators that inhibit abnormal immune function and prevents excessive blood clotting. DHA is not considered an essential fat because the body can manufacture sufficient amounts if adequate short chain omega-3 fats are consumed (flax, walnuts, soybeans, leafy green vegetables). However, because of genetic differences in the enzyme activity and because of excess omega-6 fats, many people, who do not consume fish regularly, are deficient in this important fat.
ARACHADONIC ACID (AA)
AA is a long chain omega 6 fat produced by the body, but also found in meat, fowl, dairy and eggs. Products formed from excessive amounts of this fatty acid have the potential to increase inflammation and are disease-causing. They may increase blood pressure, thrombosis, vasospasm, and allergic reaction. They are linked to arthritis, depression, and other common illnesses.
Triglycerides comprise the largest proportion of fats (lipids) in the diet, in the adipose tissue, and in the blood. Immediately after a fatty meal, triglycerides rise in the bloodstream. We store triglycerides in our fatty tissues and muscle as a source of energy, and gradually release and metabolize it between meals according to the energy needs of the body. Only a small portion of your triglycerides is found in the bloodstream. High blood triglyceride levels are reflective of increased body fat stores. High triglycerides further promote and contribute to atherosclerosis in people with high cholesterol.