Fats and Oils

First, let’s talk about why it is important to watch fats in our diet. The average American consumes 40% of their caloric intake in the form of fat. This is a very high percentage especially when it has been noted that fat intake within the 20% range is healthier. Let’s look at this nations number one disease, heart disease. It has been clinically proven that fats in the diet are related to arteriosclerosis and high cholesterol level and that by reducing intake of fats, positive results can be seen. There is a great deal of research done in this area, so we will not deal with it in this particular article. What is fat? Fats and oils are made up of carbon chains but the fat chain is a simple linear arrangement of carbon atoms. Fats are a hydrogenated carbon with hydrogen added. Technically then, fats and oils are hydrocarbons and are structurally like petroleum. There are three types of fats: Saturated, mono-unsaturated and poly-unsaturated. We will not deal with the technical nature of these types but will explain them in terms you can understand.

Saturated fats are found in animal products and are solid at room temperature. Lard is a good example as are dairy products like cheese and butter. Beef and pork products are high in saturate fats and lead to cholesterol problems.
Mono-unsaturated fats are liquid at room temperature and are the best form of oils to use. Olive and sesame oils are of this type. This type of fat does not affect blood cholesterol levels.
Poly-unsaturated fats are liquid at room temperature and are similar to mono-unsaturated. The main difference is in the bonding between molecules. Most vegetable oils are this type (corn, safflower, peanut, etc). They can help to reduce cholesterol only if they are unhydrogenated.
Many people ask which is better: butter or margarine. Margarine is a hydrogenated, saturated product that was developed and used widely during World War II because butter was in short supply. Some margarine is often advertised as ” made from poly-unsaturated oils ” and in fact has small quantities of liquid poly-unsaturates that are added to a hydrogenated base. Margarine also is high in trans fatty acids, which have a detrimental effect on the body. Butter is saturated but the molecular chain is different than other saturated fats. It is semi-soft at room temperature and studies show that some butter can be beneficial to the body. Of course it depends on how much a person uses. Remember moderation is the key.

Let’s discuss cholesterol. What is cholesterol? Cholesterol is a waxy, fat – like substance that is found in every cell in our bodies. It is the base from which estrogen, cortisone, cortisol and testosterone are made. It is a component of nerve tissue. One end of the molecule can form a salt, which is soluble in water, and the other end combines well with fat. Cholesterol salts, (bile salts) promote the mixture of fats in the small intestines with water so that they can be broken down and absorbed through the intestinal wall. Cholesterol is not the villain that we are led to believe. The body can synthesize all of the cholesterol that it needs primarily in the liver. The problem with cholesterol arises when we get too much in the blood stream, either produced by the body or through diet. The average cholesterol count for Americans is 225-250 mg. per 100 ml. of blood serum. The cholesterol levels for vegetarians and those on low fat diets range

from 150-175 mg. per 100 ml. of blood serum. This is a significantly lower level and studies show these people have lower incidence of heart problems. When cholesterol levels are high the molecules begin to attach to the arterial walls. There are two forms of cholesterol, HDL (High density Lipo-proteins) and LDL (Low density Lipo-proteins) High HDL is said to be beneficial because the molecular structure is in a loose structure and the molecules are bigger. They are easier to metabolize. The LDL is what comes through dietary sources and is a smaller grouping of molecules, harder to break down.

Since we have discussed how fats affect our body lets discuss oils and what’s been done to them. There are two methods of preparing oils. The first is pressure. The ground or flaked oil bearing material is fed into a large cylinder and driven against a back plate by a big screw. The tremendous pressure squeezes out 95% of the oil. The second method is the solvent method. The ground material is bathed in a solution of hexane or some other petroleum solvent. The resulting oil solvent solution is then boiled to drive off the solvent. This is the most popular method used with commercial oils because only 1-2 % of the oil is left in residue. Remember our ” all natural oil? Natural oils are never prepared in this manner.

Commercial oils go through a few other steps before you buy it off the grocery shelf. First the oil is washed with a sodium hydroxide solution to remove the phosphatides, one being lecithin. Phosphatides cause oil to darken in high heat. Next caustic soda combines with the oil’s free fatty acids to form soap stock. Then the oil is filtered through bentonite, clay, to bleach it by removing minerals and color components like chlorophyll and carotenoids. The next stage is to heat the oil by steam to 446 degrees to deodorize it. The last stage hydrogenation, an optional stage, in which many of the oil’s poly-unsaturates are saturated with hydrogen to stabilize the oil. This is done to give oil a longer shelf life. In many cases, BHT or BHA, anti-oxidants, are added then to prevent rancidity.

Now that you know the process that oils go through, what alternatives do you now have to choose from? We use oils that are mechanically pressed which have been through the least amount of processing. The oils do have color and flavor but they also have nutrients that other oils don’t have. The digestibility of pure oils is better and they don’t lead to build up problems in the arteries. A natural oil has a shelf life of 4-6 months depending on storage conditions. We recommend storage either in a refrigerator or in a cool, dark shelf. How do you know if an oil if fresh? Tasting oil and smelling it are the best ways. If oil is rancid your nose will tell you immediately. With a little practice you will be able to tell. Remember that fats in the diet need to be reduced and the best way to do this is to read labels and control the amount used in your own preparation.

For additional reading of fats and oils read Laurel’s Kitchen by Laurel Robertson, and Diet And Nutrition by Rudolph Ballantine.