The subject of dietary fats has been the focus of hot debate for more than fifty years. Beginning in the 1950's, we were all encouraged to reduce fats in our diets, particularly saturated fats. In the 1980's the anti-fat sentiment was so great that authors such as Dean Ornish and Robert Haas were suggesting that fat intake be practically eliminated ...slashed to a mere trickle. "Fats make you fat," we were told. And if that's not bad enough, saturated fats cause a myriad of illnesses from cancer to heart disease and most nasty things in between.
Then in the 1990's, thanks largely to the popularity of Dr. Udo Erasmus' writings and product marketing, we were informed that there are some "good" fats (this idea was always around, but had been lost in the anti-fat craze of the 1980's). Polyunsaturates are good for us, and a particular type of polyunsaturated fat (which Dr. Erasmus happens to profit from the sale of) can prevent and cure the problems associated with the "bad" saturated fats. We were told, and are still advised, that the proper balance of Omega-6 to Omega-3 fatty acids can improve our physical and mental health and even directly cause us to lose body fat.
In this three part series I'm going to cover what my 16 years of studying nutrition and biochemistry has taught me. I'm also basing this on my own personal experience, the experiences of people I've advised and the experience and advice of drug-free Bodybuilders and Weight Lifters over the past 100 years. This information is not intended as a way to treat disease or to be used in lieu of a physician's advice. I don't have any specific training in disease treatment (although, to be perfectly honest, I have little faith in much of the nutritional information that med school students and, in particular, dieticians are taught) and I simply don't want that responsibility. It's not my intent to be politically correct in a nutritional sense, and I'm not interested in arguing with people about nutrition. I will be doing this from the perspective of athletic strength performance ...building muscle and getting stronger.
|Fatty acids travel around in your bloodstream and are stored in the fat cells in a form called triglycerides. A triglyceride is a molecule comprised of three fatty acid molecules connected to one glycerol molecule. Fatty acids are typically in triglyceride form in the plants and meats that you eat as well.|
|Saturated and Unsaturated Fatty Acids|
|There are two main types of fats: saturated and unsaturated. For all you people out there familiar with organic chemistry, saturated fats have no double bonds along their carbon chains, meaning that they are saturated with hydrogen atoms. Unsaturated fats have one or more double bonds, meaning that they are not saturated with hydrogen atoms. If the fatty acid has only a single double bond (meaning the fatty acid could accept two additional hydrogens), then it is called "monounsaturated". If it has more than one double bond (like omega-6 and omega-3 fatty acids) then it is called polyunsaturated. For those of you not familiar with organic chemistry, don't worry about it, this isn't going to be a chemistry lesson. For now, we just need to know that there are basically two types of fats in our diets - saturated and unsaturated.
A triglyceride molecule doesn't have to contain three of the same type fatty acids; it can have a mixture of different saturates and unsaturates.
|Short, Medium and Long-Chain Fatty Acids|
|Fatty acids can also be categorized based on how many carbons atoms they contain. Short chain fatty acids (SCFAs) have two to four carbons. Medium-chain fatty acids (MCFAs) have eight to 12 carbon atoms, long-chain fatty acids (LCFAs) have from 14 to 18 carbon atoms and very-long-chain fatty acids (VLCFAs) have from 20 to 24 carbon atoms. All SCFAs, and most naturally occuring MCFAs, are saturated. Common LCFAs can be saturated or unsaturated. VLCFAs are usually highly unsaturated.
Sometimes you'll see these fats referred to by their triglyeride configuration rather than the fatty acids themselves. For example, rather than say a food contains medium chain fatty acids, the author might say the food has medium chain triglycerides (MCTs). For our purposes such distinction isn't important.
|Fats and Oils|
|Fats composed mainly of saturated fatty acids tend to be solids at room temperature. In this case, we call them simply "fats". When most of the fatty acids present are unsaturated it tends to make the substance liquid. In that case, we call it an "oil". Basically, fats are solids at room temperature and oils are liquids.|
|Hydrogenated Oils and Trans Fatty Acids|
|Some of you may be wondering why margarines are made of mostly polyunsaturated vegetable oils yet they are solid. The answer is because manufacturers, through the process of hydrogenation, add more hydrogen atoms to the fatty acids in order to make them more saturated. Fully hydrogenated vegetable oils will be completely solid. Whereas partially hydrogenated oils will be solid, yet softer than if they were completely hydrogenated ...these are your margarines. Incidently, manufacturers add artificial colouring to margarine to give it a golden "butter" colour - otherwise it would resemble an unappetizing wax.|
Now that we have some basic knowledge of how fats and oils are made up and categorized, we can get on with the physiological effects of fats, oils and cholesterol. After all, we're looking to see how these these can influence our strength, muscle, body fat and health. I'm going to start with some pretty "radical" statements when viewed in light of today's popular conceptions about dietary fats. I might go against some things you've taken as fact for years. Keep in mind that I have no motivation to present any of this information other than to help you make informed, unbiased decisions, free of commercial influence. So let's jump right in at the deep end...
The lipid hypothesis is the theory that there is a direct correlation between the amount of saturated fats and cholesterol in the diet and the incidence of coronary heart disease. This idea first gained ground with Ancel Keys' research in the early-to-late 1950's. As entrenched as this idea has become over the past 50 years, however, many lesser publicized studies have refuted this claim. In fact, noted authorities such as Dr. Mary Enig, Dr. Uffe Ravnskov and even Dr. Udo Erasmus have cast serious doubt on the Lipid Hypothesis. A large-scale, multi-decade population study (known commonly as the Framingham, Massachusetts study) found a correlation of only 0.36 between total serum cholesterol levels and atherosclerosis. Statistically, this does not indicate a clear link between total serum cholesterol level and "blockages".
The relation between high saturated fat intake and increased serum cholesterol has also been questioned. Recent research has indicated that certain saturated fatty acids in the diet do not raise serum cholesterol levels. Other studies have indicated that saturated fats raise high-density lipoproteins (HDL - the substance which carries cholesterol to the liver for metabolizing and elimination) and low-density lipoproteins (LDL - the substance which carries cholesterol through the bloodstream to the tissues) in roughly equal proportions. It has been shown in many studies that polyunsaturated fats (the "good" ones, as we've been told) lower total serum cholesterol, but there has also been evidence presented that they lower HDL more than LDL, resulting in an overall less healthy serum cholesterol profile. Recent research has indicated that saturated fats raise HDL levels more than any other type of fat (with monounsaturates raising HDL as well). If this seems complex, then that's because it is. And while it does appear clear that if your HDL level is high then you have lesser risk of heart disease regardless of how high your overall total cholesterol level is, very little else about fats and disease is equally clear.
According to Dr. Mary Enig, the director of the Framingham study commented, "In Framingham, Massachusetts, the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower the personís serum cholesterol... we found that the people who ate the most cholesterol, ate the most saturated fat, ate the most calories, weighed the least and were the most physically active." The Lipid Hypothesis is simply that, a hypothesis, and today, 50 years after it's proposal, it still hasn't been convincingly established.
This isn't to say or imply that there is no link between HDL, LDL, fat intakes, cholesterol and athersclerosis. My point is simply that research has yet to establish exactly what fats are "bad" for you, what fats are "good" for you and what role dietary cholesterol plays in all of this. My own thoughts on this subject, after many years of personal research and dietary experimentation, is that this all may be, as Shakespeare said, "much ado about nothing".
Many cultures have traditionally consumed, and continue to consume, large amounts of foods high in saturated fat and cholesterol such as meat, milk, cheese and eggs, yet coronary heart problems are very rare amoung them. Of course, this could be because the French have a glass of red wine with dinner, or the Italians dip their bread in olive oil, or the Eskimos eat seal meat which contains omega-3 fatty acids ...but those reasons only need be presented if we are actively seeking an explanation as to why their high saturated fat intakes don't seem to be negatively affecting their health (operating from premise that high saturated fat intakes should negatively affect their health). By comparison, the consumption of traditional animal fats in North America has dramatically decreased during the past fifty years, yet in that same period heart disease has gone from a medical rarity to the number one killer of Americans. Clearly, the Lipid Hypothesis is either false or incomplete.
No doubt, much of what we've been told is due to the western food industry's heavy investment in, and reliance upon, vegetable oils in the processing of foods. Like the Bodybuilding supplement industry, there is much money at stake (but, in this case, literally trillions of dollars) and truly unbiased information is hard to come by. What you can be certain of, however, is that the unreasonable fear of saturated fats and cholesterol must be overcome if you're to make your maximum drug-free progress with weight training.
CAVEAT: It is a function of LDL to carry cholesterol though the bloodstream to repair cellular damage to artery walls. Primary culprits in causing this artery damage are high insulin levels and free-radicals. In reponse to this, LDL carries cholesterol to the damaged area and "plugs" it by forming a plaque-like coating over it (like repairing a leak in a tire). When the build-up of plaque becomes so large that it restricts blood flow, or if pieces of it break off and travel down the bloodstream to get caught in smaller capillaries, is when problems occur. Convincing evidence indicates that it is oxidized (i.e. processed) cholesterol which is responsible for the excessive build-up of plaque on artery walls, not healthy, natural cholesterol. Unprocessed foods such as eggs, liver and meat DO NOT contain high levels of oxidized cholesterol. In already healthy individuals, the solution to avoiding atherosclerosis is not the avoidance of saturated fats and natural cholesterol in the diet, but rather preventing artery damage in the first place and the avoidance of oxidized cholesterol. That is done by limiting processed foods, not consuming excessive amounts of polyunsaturated fats, and maintaining a high intake of fat soluble antioxidants (such as vitamins E and A). In other words, eating a balanced natural diet.
If you already have artery damage, however, or are an insulin dependent diabetic, it is wise to maintain a high blood HDL to LDL ratio. This appears to be most effectively done by consuming most of your dietary fats in the form of monounsaturates and, possibly, polyunsaturates. Dietary cholesterol may not have a large affect on the blood cholesterols of some people because the body manufactures its own cholesterol and will adjust how much is manufactured in response to how much is consumed - eat more cholesterol and your body manufactures less, eat less and your body manufactures more. This occurs in varying degrees in different people, so the precautionary approach is for high-risk individuals to also limit dietary cholesterol ...though keep in mind that the link between unoxidized dietary cholesterol and atherosclerosis has never been firmly established.
If you are already healthy, and have no arterial damage or medical condition causing a propensity for blockages, then there is no reason to avoid saturated fats and natural cholesterol in the diet. In fact, it is detrimental to health to do so. For the rest of this series on dietary fats I am going to assume that you are healthy and not a high-risk individual for heart disease.
If you have an existing medical condition pertaining to atherosclerosis it is always safe to take the most conservative path possible. In that case, it may be necessary to modify the advice given in this series to fit your problem. Consult a physician who is knowledgeable in this specific area.
Our ancestors didn't have access to modern commercial crops. By necessity, they became expert hunters. As a consequence of their lifestyle, primitive humans consumed higher levels of animal fats and low levels of vegetable, fruit and grain fats. (With the exception of some tropical plants, vegetables, fruits and grains contain very little oil. In order to produce commercial vegetable and grain oils manufacturers have to crush, heat and chemically treat large quantities of vegetables/grains in order produce a few tablespoons of oil.) Because of this, modern man's digestive system is much more suited to digesting animal products than large quantities of grains and the like. Our digestive tracts are simply too short to efficiently digest large amounts of grain products.
Why then, if the ancestors of modern man from homo erectus on up (about 2 million years worth of evolution) consumed low quantities of vegetable/grain fats and high quantities of animal fats, would we conclude that animal fats are "bad" for us and vegetable/grain fats "good"? If that is, in fact, the case, either something is wrong with the theory of evolution or evolution has played a strange trick on human beings.
Short chain fatty acids (SCFAs) and medium-chain fatty acids (MCFAs) "behave" very differently in the body than long-chain fatty acids (LCFAs) and very-long-chain fatty acids (VLCFAs). The long-chains triglycerides (LCTs) and very-long-chains triglycerides (VLCTs) that you eat are broken down by enzymes in the gut and absorbed through the wall of the small intestine. They are then recombined into triglycerides and carried through the bloodstream, by-passing processing by the liver, to the various organs and tissue of the body (including the fat cells). This means that the LCFAs and VCLFAs, whether they are saturated or unsaturated, can be easily stored as body fat when you eat too many of them. As mentioned before, common LCFAs can be saturated or unsaturated and VLCFAs are usually highly unsaturated.
SCFAs and MCFAs, on the other hand, are metabolically difficult to store as fat. Differing from LCFAs and VLCFAs, they are carried to the liver for conversion to energy before they go through the bloodstream to the organ, fat and muscle cells. Excess SCFAs and MCFAs can be quickly converted into ketone bodies and excreted in the urine ...sparing you from storing them as body fat. In addition, they contain slightly fewer calories per gram than the longer chain fatty acids (I've seen varying claims of just how much fewer, so I won't put a number value on it here). As mentioned before, all SCFAs, and most naturally occuring MCFAs, are saturates.
But before you decide that you'd just like to stick to SCTs and MCTs and avoid all other forms of fats because they'll make you fat, consider this list, from experts Mary Enig and Sally Fallon, of important roles that saturated fats, in general, play in the human body:
In addition, any type of LCFAs or VLCFAs in the diet will slow digestion, assuring the body of a more gradual supply of nutrients from the other foods present in the digestive tract. This includes lowering the rate at which dietary carbohydrates increase blood glucose and thus decreases insulin release.
Of particular interest to weight trainers is that all dietary fats facilitate the permeation of the muscle cell by testosterone, which, of course, initiates the growth process.
Almost all vegetable/grain oils and animal fats have high amounts of LCFAs (always a mixture of the saturated and unsaturated kinds) with fish (especially some cold water species) supplying the highly unsaturated VLCFAs. Coconut oil is over 64% saturated MCFAs and butter is over 12% saturated SCFAs and MCFAs. Coconut oil contains high levels of lauric acid (a saturated MCFA) which has powerful antibacterial, antifungal, immune-system-supporting and absorption enhancing properties. Butter and full-fat milk also contain small amounts of lauric acid. The SCFAs and MCFAs in coconut oil, butter and milk promote digestive system health and enhanced absorption of foods. When taken in place of LCFAs, research has indicated that they increase metabolism and promote fat loss. Based on this, it is reasonable to conclude that coconut oil results in less calories deposited as body fat than other oils, and butter is less body fat-producing than margarines.
In their natural states, most vegetable/grain oils are liquids and, therefore, unable to be used in many commercial food products and baking. To overcome this, manufacturers "stiffen" them up by partially and fully hydrogenating them (inserting hydrogen ions into the double bonds of the polyunsaturated and monounsaturated fatty acids). This allows margarine to be made from vegetable oil, but it also produces massive quanties of "trans" fatty acids (so named because of their physical structure). In high quantities, these become some of the most toxic and dangerous "food" elements you can put into your body. They do not behave the same as saturates, but because they are both solids at room temparture, and have similar geometric shapes, it is common for nutritionalists to lump the two groups together. Some of the negative actions of trans fatty acids are:
Avoid products containing hydrogenated and partially hydrogenated vegetable/grain oils.
Let me leave the subject of saturated and trans fats with something purely from my own experience and the experiences of others I have advised and taken advice from: Without saturated fats you will never make maximum progress in the gym and with your physique. All sex hormones (testosterone, estrogen, etc.) are produced from cholesterol via the process of steroidogenesis. Deliberately limiting the dietary intake of saturated fats and cholesterol in a natural athletes diet is also deliberately limiting testerone levels and results in the gym. It is an established fact that strict vegetarians (vegans) have lower average testosterone levels than people who consume animal products.
All fats contain roughly 9 calories per gram (though I've seen slightly lower estimates for MCTs), and LCFAs and VLCFAs have a low thermic effect and are stored easily as body fat. Keep this in mind, and don't overindulge on any LCFA- or VLCFA-containing foods. This applies to both saturated and unsaturated fats. However, if you have an unreasonable saturated fat phobia, now is the time to begin adpoting a more balanced outlook with your diet. Your training progress will be your reward.