Fats and Oils and Cholesterol
There are so many different types and categorizations of fats and oils that it is extremely confusing to know what to shop for and what to avoid. For many years fats have taken the brunt of the blame from nutritional authorities for the increasing incidence of heart disease and arteriosclerosis. It was clear to some nutritionists that all fats were bad, and that Americans should eat as little of them as possible. This whole issue makes another fascinating study of how politics and business affect science in this country, but that will have to wait for another day.  Thus began the promotion of low fat diets during which time Americans as a group have become more overweight than ever before, and make lipid lowering dugs among the best sellers for the pharmaceutical companies. Well it turns out that has been very bad advice, and that in fact there are some fats which are absolutely essential to health, and others which exert favorable effects on disease states. Are you tired of being completely confused? Then read on, because I am going to keep this simple and easy to understand.

The chemistry term lipid is all encompassing, and includes triglycerides, phospholipids, sterols, and waxes. Trigycerides is the correct technical term for the everyday fats (solid at room temperature) and oils (liquid at room temperature) we all know about, although we usually only hear the term in the doctor’s office when our blood tests are being discussed. Both fats and oils consist of 3 fatty acid molecules combined with one molecule of glycerol, thus the name. The fatty acids in the triglycerides can be short, medium, or long chained depending on how many carbons in the chain of the molecule. Further, within each type, the fatty acid molecules can be either saturated (no double bonds), monounsaturated (one double bond), or polyunsaturated (many double bonds). None of these types of fatty acids are ESSENTIAL to us except several poly-unsaturated fats that will be noted below. When the fatty acids are primarily unsaturated, the substance will usually be from a plant source and will be liquid at room temperature. Finally, depending on where in the carbon chain the double bond is located, the fatty acid can be referred to as omega 3 (EPA/DHA), omega 6 (Borage oil, evening primrose oil, or black currant seed oil, other vegetable oils), or omega 9 (oleic acid monounsaturated in olive oil) with double bonds located at the third, sixth, and ninth carbon atoms respectively.

Certain fatty acids are essential to human life. That is, they cannot be manufactured within the body and must be supplied from the diet. Essential fatty acids include alpha linolenic (an omega 6 fatty acid) and linoleic acid, and the body will convert these into the polyunsaturated fatty acids (PUFA’S) which are used for cell membranes (EPA and DHA) and to produce prostaglandins (like arachidonic acid), chemical messengers involved in many body functions. Fats (such as Crisco, lard. suet, butter, and the fat on red meat) are primarily composed of saturated fatty acids which are stable at high temperature, resist the oxidative process called rancidity, and usually derive from animal sources. Oils (like canola, flax, sunflower, and olive) are more likely to contain unsaturated fatty acids and are more prone to oxidative rancidity from exposure to air, light, or high temperatures. Exceptions are palm and coconut oils which are plant based, mostly saturated, yet liquid at room temperature.

After cholesterol became a buzz word in American society about 30 years ago, we were exposed to a lot of propaganda telling us that all saturated fat was bad and polyunsaturated oils were good. That is still the conventional wisdom of today. The problem is what happens to poly-unsaturates when they are used in cooking at high temperatures, when rancidity sets in, or when they are hydrogenated and hardened into shortening or margarine.  What happens is they convert into the “trans” form of the lipid molecules, i.e., hydrogen atoms are rearranged in such a way that they occupy opposite sides of the two carbon atoms, and changes the shape of the molecule. Though technically still unsaturated, the product is now solid at room temperature and many of the health benefits of the polyunsaturated oil is lost.  Trans fats are also found in many other foods besides margarine and shortening, including fried foods like french fries and fried chicken, doughnuts, cookies, pastries and crackers. Store-bought bakery goods, junk food, fried foods, and convenience foods may contain as much as 40-50% trans fatty acids. Trans fat is known to increase blood levels of low density lipoprotein (LDL), or "bad" cholesterol, while lowering levels of high density lipoprotein (HDL), known as "good" cholesterol. It can also cause major clogging of arteries, type 2 diabetes, cancer, obesity, and other serious health problems, and was found to increase the risk of heart disease.

Many food companies use trans fats to reduce costs, extend storage life, and improve flavor and texture. Food manufacturers are not required to list trans fat content on labels until 2006, so reading labels generally doesn’t help you here. For now, you just have to know that the higher up hydrogenated or partially hydrogenated vegetable oil is on the ingredient list, the more trans fat there will be in that product. There is really no safe amount of trans fat to eat, and it is now known that this form is much more dangerous to our health than saturated fats. Because molecules of trans fats look identical to functional natural “cis” fat molecules (except that the hydrogenation or partial hydrogenation process of the original oil has altered them specially) the body will attempt to incorporate these rogue molecules into essential structures and processes, but because of their trans natures, they will “gum up the works”. On the other hand, remember that supposedly evil saturated fats like butter and coconut oil actually are safer and can even provide notable health benefits.

The medical terminology you need to know is this. Cholesterol is a sterol molecule, more waxy than fatty but still a type of lipid. It is made in the liver of mammals, and also is found in some animal foods like eggs and meat. It is a unique molecule that bears no resemblance to triglycerides, and contains no fatty acids. It is not found in plants, nor is it necessarily an ingredient in saturated fat. People often confuse the two. They are not the same. Natural peanut butter and coconut oil, for example, are almost all saturated fat, but contain zero cholesterol.  It has many crucial functions within the body, is a precursor for many hormones and other body chemicals, as well as having an awful and undeserved reputation of causing heart disease. Dietary intake is an insignificant source of the cholesterol found in your blood stream. In the body the two types of cholesterol are LDL and HDL. Low fat diets don’t work for weight loss or to prevent heart disease. There is poor scientific basis for a diet-heart disease causal connection. High triglycerides surprisingly are usually due to overuse of starchy foods and sugar, and have almost nothing to do with fat in the diet. I know from years of direct clinical experience that triglycerides are dramatically lowered by eating a diet higher in protein and saturated fats, and lower in sugar and refined carbohydrates, not by eating low fat!

So, here is the bottom line. Olive oil is good for you, but it is not ideal for cooking because of the less stable monounsaturated fatty acid content. Some experts will dispute whether there is much if any formation of trans fatty acids when olive oil is heated, while others insist the monounsaturated fat makes it more prone to this. I feel that the best solution is to not use high heat when cooking with olive oil. None of the shortenings and other polyunsaturated vegetable oils you can buy at the grocery store should be used for cooking. Hydrogenation, instability at high temperatures, and the formation of trans fatty acids make their use inadvisable.

Coconut oil is an excellent alternative for cooking (even at high temperatures) that is extremely stable and has general health benefits as well. Butter can also be used for cooking, and is MUCH healthier than margarines which should never be used. Most packaged convenience foods, fried and junk foods, and bakery products contain large amounts of dangerous trans fats. Avoid them because they can cause many health problems. Humans require alpha linolenic (ALA) and linoleic acid to be present in the diet. Flax oil is a good source of ALA, but since ALA does not easily convert to EPA or DHA in the body, those interested in raising the levels of omega 3 fatty acids should do so by supplementing with fish oil capsules or cod liver oil instead. Generally it has been thought that Americans consume excess omega 6 fatty acids as compared to omega 3. This fact is thought to account for the high incidence of various health problems in this country. This is not universally agreed upon, however, and some think it is more a matter of avoiding hydrogenated omega 6 fats while maintaining a research-derived dietary omega 6/3 ratio of 4/1 using healthy vegetable oils as a supplement or on salads. If you have medical problems see your physician for analysis of red blood cell membrane composition which will accurately assess fatty acid balance in your body.

So to sum up, contrary to conventional wisdom, saturated fats can be good for you, polyunsaturated fats may actually be bad for you depending how you use them, and hydrogenated or partially hydrogenated vegetable oils with associated trans fats are ugly and can kill you early. Avoid all hydrogenated fats and fried foods, use fresh monounsaturated oil like olive oil with your food, but cook with coconut oil or butter. Oils are powerful medicine so supplement with other fats and fatty acids on the direction of your doctor who can test your fatty acid balance as necessary.