Nexus - 0402 - New Times Magazine-pages

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THE CHEMISTRY OF FATS Fats are carboxylic esters derived from the sin- gle alcohol, glycerol [C;Hs(OH)s], and are known as "glycerides". Each fat is made up of glycerides derived from many different carboxylic acids (fatty acids). There are three fatty acid chains in each molecule of fat. The proportions of the vari- ous acids differ in each type of fat, while each fat has its characteristic composition which differs very little between samples. With only a few exceptions, the fatty acids are all straight-chain compounds that vary between three and 18 carbon atoms. Besides "saturated" fatty acids, there are also "unsaturated" fatty acids containing one double bond or more per molecule. When one of these fatty-acid chains in a fat is replaced with a phosphate group, we get sub- stances called "phospholipids". These derivatives of fats are very important as they make up the membranes of cells. Morrison and Boyd, in their textbook, Organic Chemistry,* had the following to say about fats and cell membranes: "Phospholipids are found in the membranes of cells—all cells—and so are a basic structural ele- ment of life." They also form skins around all the organelles within our cells, such as mitochondria, the nucleus, nucleolus, lysosomes, Golgi bodies, etc. "This vital function depends on their physical properties." One end of the molecule dissolves in water and the other doesn't. Therefore, in cell walls they exist in a bilayer. The phosphoglyceride ends form the outside of the layer, as these dissolve in water. The bulk of the bilayer is made up of the fatty acid chains. "Non-polar molecules can therefore very easily dissolve and pass through this bilayer, but it is an effective barrier to polar molecules and ions." So how do these membranes very selectively control the passage of substance in and out of the cells? "The answer...seems to involve the proteins that are found in the cell membrane embedded in the bilayer, and even extending clear through it." These help with the active transport of certain sub- stances. "Now, if the transport protein is to do its job, it must be free to move within the membrane. The molecules, while necessarily aligned, must not be locked in a rigid crystalline lattice—as they would be if the fatty acids were saturated (or in the trans- form). Actually, some of the chains in the mem- brane phospholipids are unsaturated, and these, with their cis- double bonds and the accompany- ing bend, disrupt the alignment enough to make the membrane semi-liquid at physiological tem- peratures." From this explanation we can begin to understand the huge importance of these cis- unsaturated fatty acids to all the basic processes of life. Cholesterol is another molecule found in the cell membrane between the fatty-acid chains. Its function is to compensate for changes in mem- brane fluidity. It can be added to stiffen a mem- brane that is too loose, or removed to fluidise a membrane that is too loose. — Eds. reaction to take place. It causes about half of the cis- bonds to flip over into a trans- configuration. Hydrogenation became popular in the US because this type of oil doesn't spoil or become rancid as readily as regular oil and therefore has a longer shelf-life. You can leave a cube of margarine sitting out for years and it will not be touched by moulds, insects or rodents. Margarine is a non-food! It would appear that only humans are foolish enough to eat it! Because the fats in margarine are par- tially hydrogenated (i.e., not fully saturated), the manufacturers can claim it is "polyunsaturated" and market it to us as a healthy food. Many other fatty chemicals are also created when oils are partially hydrogenat- ed. In Fats that Heal, Fats that Kill (p. 103), Udo Erasmus stated: "So many dif- ferent compounds can be made during partial hydrogenation that they stagger the imagination... Needless to say, the industry is hesitant to fund or publicize thor- ough and systematic studies on the kinds of chemicals produced and their effects on health." Erasmus also quoted a statement about hydrogenation, made by Herbert Dutton, one of the oldest and most knowledgable oil chemists in North America. It basi- cally boils down to this: because of the known and unknown health effects of these hydrogenation by-products, government health regulations would not allow the process to be used for making edible products if it were to be introduced today. Another 'side-effect' of hydrogenation is that a residue of toxic metals, usually nickel and aluminium, is left behind in the finished product. These metals are used as catalysts in the reaction, but they accumulate in our cells and nervous sys- tem where they poison enzyme systems and alter cellular functions, endangering health and causing a wide variety of problems. These toxic metals are difficult to eliminate without special detoxification techniques, and our 'toxic load’ increases steadily with small exposures over time. Since they are increasingly found in our air, food and water, the cumulative doses can add up to dangerous levels over time. Since trans- fats don't occur in nature, our bodies don't know how to deal with them effectively and they act as poisons to crucial cellular reactions. The body tries to use them as it would the cis- form, and they wind up in cell membranes and other places they shouldn't be. In recent years, measurements of trans- fats in the membranes of human red blood cells have been as high as 20 per cent, when the figure should be zero. While red blood cells were used because they're easy to access, it's safe to assume that most other cell membranes in the body also contain these unnatural fats. Trans- fatty acids in cell membranes weaken the membrane's protective struc- ture and function. This alters normal transport of minerals and other nutrients across the membrane and allows disease microbes and toxic chemicals to get into the cell more easily. The result: sick, weakened cells, poor organ function and an exhausted immune system—in short, lowered resistance and increased risk of dis- ease. Trans- fats can also derail the body's normal mechanisms for eliminating cho- lesterol. The liver normally puts excess cholesterol in the bile and sends it to the gall bladder, which empties into the small intestine just below the stomach. Trans- fats block the normal conversion of cholesterol in the liver and contribute to elevated cholesterol levels in the blood. They also cause an increase in the amount of low-density lipoproteins (LDLs), considered to be one of the main instigators of arterial disease (hardening of the arteries). Meanwhile, trans- fats lower the amount of high-density lipoproteins (HDLs) which help protect the car- diovascular system from the adverse effects of the LDLs. Trans- fats also increase the level of apolipoprotein A, a substance in the blood which is another risk factor for heart disease. Indeed, trans- fats have now been shown to cause even worse problems than saturated animal fats. Another adverse effect of trans- fats in the diet is an enhancement of the body's pro-inflammatory hormones (prostaglandin E2) and inhibition of the anti-inflam- matory types (prostaglandin El and E3). This undesirable influence exerted by trans- fats on prostaglandin balance may render you more vulnerable to inflam- matory conditions that don't want to heal! Prostaglandins also regulate many metabolic functions. Tiny amounts can cause significant changes in allergic reac- tion, blood pressure, clotting, cholesterol levels, hormone activity, immune func- 40 - NEXUS FEBRUARY - MARCH 1997