Confused about fats?
If you are, it is no wonder--much of the published nutritional information about fats makes no sense whatsoever. Not only is this information contradictory, it often assumes you are familiar with terminology that only a healthcare professional or scientists would know.
For example, we looked up the word "triglycerides" in a family medical dictionary and here's what we learned:
Triglycerides are a naturally occurring ester of three fatty acids and glycerol that is the chief constituent of fats and oils.
Well, excuse us if we don't know what an "ester" is or a "glycerol." So we looked these words up, too:
An ester is any class of organic compounds corresponding to the inorganic salts and formed from an organic acid and an alcohol.
Meanwhile:
Glycerol is a syrupy, sweet, colorless or yellowish liquid, C3H8O3, obtained from fats and oils as a byproduct of saponification and used as a solvent, antifreeze, a plasticizer, and a sweetener and in the manufacture of dynamite, cosmetics, liquid soaps, inks, and lubricants.
Is it clear yet, or should we look up the word "saponification?" Well, actually, we finally agreed to come with our own definition:
Triglycerides are the main form of fat in our bodies and our food.
Not so difficult, right? One interesting thing about triglycerides is your body doesn't only store them from the fat in your food; it can actually manufacture triglycerides from excess calories from any source such as protein, carbohydrates or fat. This explains, I suppose, why eating too much pasta can make you gain weight.
Triglycerides are the chief fat in our bodies (95%) but not the only fat--there is also "phospholipids" and "sterols."
Phospolipids, are found in cell membranes and are essential to your body's ability to manufacture triglycerides-but your diet has nothing to do with these fats, so we have no reason to dwell on them.
The remaining form of fat, however, is important--the best known of the sterols is cholesterol which is type of fat that attaches itself to protein molecules to be carried through your blood vessels.
As you have probably heard or read a thousand times, there are two types of cholesterol, commonly called "bad cholesterol" and "good cholesterol."
The bad stuff is LDL, which stands for "low-density lipoprotein," while the good stuff is HDL, or "high-density lipoprotein." An excess of LDL can lead to the build up of plaque in your arteries and actually kill you.
Meanwhile, HDL fights back by carrying LDL to your liver where is can be processed and actually "excreted" from your body.
Food does not contain either HDL or LDL-food contains various forms of Triglycerides. Now, here's where things get interesting because some of these fats are good for you because they lower LDL, some are maybe good for you (or maybe not) because they lower both LDL and HDL, while the rest are definitely really, really bad for you.
The Good Fats
Let's start with the good fats:
Monounsaturated fats. Found in olive oil (73 percent), grapeseed oil (60 percent), hazelnuts (50 per cent), almonds (35 per cent), Brazil nuts (26 per cent), cashews (28 per cent), avocado (12 per cent), sesame seeds (20 per cent), and pumpkin seeds (16 per cent), these fats actually lower LDL cholesterol while leaving your HDL at the same level.
The high consumption of olive oil in Mediterranean countries is considered to be one of the reasons why people living there have lower levels of heart disease. High in Vitamin E, monounsaturated fat is also believed to offer protection against certain cancers, like breast cancer and colon cancer, though the recent Women's Health Initiative Study seems to cast doubt on this.
The message here is cook with olive oil or grapeseed oil (which has the highest flashpoint of any oil-it can be heated up to 437 degrees Fahrenheit with no smoke); eat olives, nuts, avocado and pumpkin seeds; and if you're not already on a "Mediterranean diet," you might want to read up on it. A good place to start is the following LongLifeClub article: Mediterranean Diet Extends Lives
Omega-3 fatty acids. This is the oil found in fish and in supplements including cod liver oil. Your body utilizes Omega-3s in the formation of cell walls, making them supple and flexible which improves circulation and oxygen uptake. Thus, Omega-3 is important to good cardiovascular health. In fact, consuming it on a regular basis will lower your LDL cholesterol and serum triglyceride levels. It can also reduce blood pressure.
The association between Omega-3s and human health was first observed by scientist who found it puzzling that the Inuit (Eskimo) people living in Greenland suffer very little heart disease, rheumatoid arthritis, diabetes and psoriasis even though their diets are alarmingly high in fat from eating whale, seal and salmon. Eventually the scientists figured it out-these foods are very high in a type of fat (Omega-3 fatty acids) which must be really good for you.
The American Heart Association [1] recommends you eat fish at least twice a week in order to maintain a desired amount of Omega-3s in your system. However, many people take supplements on a daily basis and/or eat fish more regularly. Omega-3s have been shown to reduce the inflammation associated with arthritis and psoriasis and may even reduce the odds of you getting dementia or Alzheimer's disease.
The two forms of Omega-3 which are most beneficial are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).
The Not so Good, Not so Bad Fats
And now on to the "iffy" fats:
Alpha Linolenic Acid. This is actually an Omega-3 found in flax seed oil and in some other foods, which is converted by your body into EPA and DHA. The American Heart Association recommends eating ALA rich foods including soybeans, canola, walnut and flaxseed; however, the extent to which your body converts ALA to EPA and DHA is limited. And some studies have linked Alpha Linolenic Acid with rapidly progressing prostate cancer and macular degeneration (yikes)-which is why I put this Omega-3 on the "iffy" list.
Omega-6 fatty acids. Like Omega-3s, Omega-6s are "essential" fatty acids meaning your body needs them but cannot manufacture them and therefore they must be obtained from eating food. (Just to make things more confusing, the most common Omega-6 is linoleic acid which is NOT the same as alpha lenolenic acid. Common sources of linoleic acid include vegetable oils, meats, grains, seeds and vegetables.)
There is suppose to be a balance between Omega-6s and Omega-3s but if you are taking an Omega-3 supplement you really don't worry about this. The average North American diet provides 10 times the necessary amount of Omega-6. Compared to Omega-3, most people have way too much of it. The ratio between the two should be 1:1 and no more than 1:4 (4 times as much Omega-6). They typical North American diets are in the range of 1:11 all the way up to 1:30. This imbalance contributes to the development of long-term diseases such as heart disease, cancer, asthma, arthritis and depression.
A recent study showed that Omega-6 acids accelerate the growth of human prostate tumors. Some researches suspect that there is a link between the increase in prostate cancer and the increase in Omega-6.
Polyunsaturated fats. Most vegetable oils including safflower oil, canola oil, sunflower oil and corn oil are polyunsaturated fat. They tend to lower both LDL and HDL cholesterol levels; on this score they are definitely a mixed bag. Like monounsaturated fats, they are liquid at room temperature. (The difference between "mono" and "poly" has to do with molecular structure which I could tell you about in elaborate detail but frankly, these type of explanations are irrelevant unless you are a chemistry student.)
In the U.S., polyunsaturated oils are commonly used for cooking which is probably a huge mistake. A toxin associated with heart disease and neurological disorders referred to as HNE (4-hydroxy-trans-2-nonenal) forms in high amounts in these oils when they are cooked. HNE has been linked in numerous studies with all sorts of nasty things including heart disease, stroke, Parkinson's, Alzheimer's, Huntington's disease, liver ailments, and cancer.
These oils are fine for salads (though olive oil is much better) but not so fine for cooking. They are found in most of the baked goods you buy in the store, so be aware.
Bad, Bad Fats
And now on to the really "bad" fats.
Saturated Fats. Solid at room temperature, saturated fats are considered by the "traditional" medical establishment to be the most detrimental of all the fats. Outside of smoking and excessive alcohol intake, they are public enemy number one.
Derived from animal products, saturated fats include butter, cheese, cream, the fat in milk and meats. Eating these fats will raise your LDL cholesterol and serum triglyceride levels and as they saying goes, "harden your arteries." They are strongly correlated to heart disease.
In recent years, of course, this iron-clad concept has gotten more than a bit rusty. First, there was Dr. Atkins who proved you could lose weight by eating a diet high in saturated fats but low in carbohydrates. Then along came the South Beach Diet which says it's not all the carbohydrates which are bad for you, just the simple ones (as compared to complex carbs). And finally, there's the Women's Health Initiative's Low Fat Diet Study which showed that saturated fats do raise your LDL levels, but not by very much.
So are saturated fats still bad? Well, yes, but not that bad. It makes sense to keep saturated fats in check, just don't obsess about it. For myself, I eat butter, cheese and use half-and-half in my coffee but then I put have drastically reduced the amount of red meat I eat.
My theory is this: a diet too high in saturated fats will still eventually kill you-just not quite as quickly as we once thought.
Hydrogenated (and partially Hydrogenated) fats-AKA "trans fats." Purely an invention of the processed food industry, these fats are polyunsaturated fats that have been turned from a liquid to a solid or semi-solid form through a chemical process which in of itself should make you very leery. It goes something like this: particles of nickel or copper are added to a polyunsaturated fat (usually corn oil) and heated to an extremely high temperature under pressure for up to eight hours while hydrogen gas is injected.
The hydrogenated process destroys the essential fatty acids in polyunsaturated fat and replaces them with a deformity called "trans fatty acids." Because your body's digestive system is the result of thousands of years of evolution, guess what, it's not equipped to process these "Frankenfats." The result is an imbalance throughout your metabolism and fatty deposits in your arteries.
You probably think hydrogenated fats are a fairly new invention but the first one was "Crisco" which was introduced to the world by Procter & Gamble in 1911. Always a great marketing company, P&G included a recipe book with each can of this gluck and by 1913 they were sending out teams of "home economists" who gave Crisco cooking demonstrations across the United States. And the beats goes on as you can see for yourself by clicking on Crisco.com
Hydrogenated and partially hydrogenated fats are found in almost every processed food from soups to chips, margarine, vegetable shortening, crackers, cookies, pastries, mixes of all kinds even including some pasta and rice mixes. They can also be found in frozen food including pizza and pot pie and of course, they are widely used in deep-fried food including French fries.
Effective this past January, the FDA is requiring all packaged food labels to specify the level of trans fats in food products. Ironically, McDonald's recently announced that an order of its French fries contains more trans fat than was previously thought (8 grams instead of 6 grams). The company promised in 2002 that it would use a new cooking oil with 48 percent less trans fat by February, 2003. As this promise never came about, McDonald's is the subject of a class action lawsuit for "false advertising."
More than any other fats, Hydrogenated, partially hydrogenated, or trans fats raise LDL levels and there is little doubt they cause obesity, diabetes and heart disease. You should simply avoid them at all costs.
No More Important Matter
One more thing that you should definitely know about fats is that all fats contain the same amount of calories. A gram of fat, whether it is a trans fat or a monounsaturated fat, has 9 calories. Meanwhile, a gram of protein or a gram of carbohydrates only has 4 calories (a gram of alcohol has 7). For this reason, it is a good idea to eat less fat-the rule of thumb is fat shouldn't be more than 30% of your diet.