Every day we hear about either the benefits or side effects of fat consumption and some time it is hard to make sense of any of it. Fred Pescatore, MD, MPH, CCN explains how fats are made and processed in his feature The Production of Oil – Move over OPEC
I wanted to just focus on trans-fatty acids in this chapter but realized that in order to understand trans-fats, it is important to know how oils are produced and processed. As in most other components of our food supply, the product isn’t so bad when it first starts out; it is what we do to the product that makes it unhealthy.
I was explaining this process to Jim, a 52 year old gentleman who wanted to go down in the book as the guy who said, “This is the easiest diet I have ever been on.” He lost 75 pounds in 7 months and hadn’t been this thin since college. He felt terrific, had come off all of his diabetes and high blood pressure medications and his cholesterol and triglyceride levels were better than they had ever been. He wanted people to know that he attributes this to becoming monounsaturated rich. He had no idea that oils went through so much processing before they reached his table. He thought that he was always doing the right thing by using olive oil exclusively. Jim wanted my new readers to know that the only reason he stuck to this diet and the only reason he knows it worked for him was because of his exclusive use of Macadamia nut oil – a totally non-processed oil.
Oils have been extracted from plants for thousands of years. It is again only very recently in modern man’s history that we started to use machinery to increase the efficiency of the extraction. Unfortunately, the methods we now employ transform the fatty acid content of the oil and make it unhealthy and potentially dangerous. Since so many of you have heard the terminology but may not know what these methods really are, here is a brief synopsis of extraction methods – some better for us than others.
Stone Pressing – is the traditional method of extracting oil from seeds and olives. This method is still employed for some very expensive olive oils. Stone pressing generates very little heat and therefore the oil retains whatever natural anti-oxidants are present.
Hydraulic Pressing – is traditionally used for avocados, some olives and walnuts. In this type of pressing, the oil is squeezed out from the ground-up material by means of a weight applied from above with the aid of a crank. This is the traditional way of extracting extra-virgin olive oil; however, just because it is traditional does not mean it is the way it is done today.
Mechanical Pressing – this is also known as expeller pressing and is basically the same as above only machines are involved to turn the crank. However, because the machine can turn the crank much more quickly than any human could, friction is created and this produces heat – temperatures up to 190 F. Since mechanical pressing is also known as cold-pressed, it is really important to know that the product is being heated in the processing. This is a more expensive way to produce oil, if the processing stops at this stage, since it takes more raw materials to generate an equivalent amount of product than if the oil undergoes the next step. In order to ensure that this is the only thing that happens to the oil you purchase, the label must read: “100% mechanically or expeller pressed.” If it does not say that, then the next step occurs.
Solvent Extraction – this was invented so that the residual pulp left over from the above method could have the remaining oil removed, about 10%. During this process, the residual raw material is exposed to hexane, a volatile solvent that is considered carcinogenic and hazardous by the Environmental Protection Agency (EPA). The oil is then heated to around 230 F so that the hexane supposedly washes off. However, microscopic traces of hexane are still found in most commercial oils. The residual meal is then sold as animal feed so that our animals, another critical component of the food chain, are exposed to this hexane that has not been washed off. The animal stores any toxins it comes into contact with in its tissues and then we eat it – not very appetizing or healthy.
Mechanical/Solvent Extraction – this is the most common method in use today and the main reason why olive oil prices are so low. The raw material is crushed at temperatures up to 230 F. The oil is then squeezed out at extremely high pressures, causing the oil to heat even more. During this process, the oil is exposed to light and oxygen which can further break down its chemical structure leading to enhanced free radical damage. Then, a solvent, usually hexane is introduced to the meal to get that last 10% of oil or so. Any pesticide residue on the raw material will stick during the solvent procedure. The oil is then heated to remove the solvent and this high temperature causes the weak bonds of a polyunsaturated fat to break apart (canola, safflower, sunflower, etc.) thereby creating even more free radicals. The natural anti-oxidant properties and natural preservatives of the oil are lost and preservatives have to be added such as BHT and BHA – two substances that are both suspected of causing cancer.
Macadamia nut Oil Packing – This is a specialized mechanical extraction system in which the oil is extracted in a no-oxygen, light free environment. The expellers are kept at very low temperatures – around 70 F, using equipment that is made from non-reactive metals such as stainless steel. This process keeps the fatty acid content intact, does not destroy all the natural anti-oxidants and preservatives, and decreases the chances of having any free radical damage. There are no chemical solvents used. The nuts are tested for pesticide residue by the Australian government and there are none. The nuts are grown in their ideal climatic conditions, 100% expeller pressed under cold conditions, not chemically extracted, filtered or bottled. The naturally occurring vitamin E, carotenes, chlorophyll, phytosterols, and phospholipids like lecithin can all be found in Macademia nut oil. The shelf life is 5 years if kept in ideal conditions. The meal that is left after pressing is given to animals and since there is no chemical residue this is quite a healthy alternative for feed, as opposed to corn that has been laced with antibiotics and growth hormone.
When I tell patients this, they immediately want to go out and buy Macademia nut oil and throw all their other oils away, I can’t really blame them. Just ask Marjorie. She went from a size 26 to a size 14 dress in 8 months on the Hamptons diet. She was on a different low carbohydrate diet and not experiencing much success when her girlfriend told her about my method. She liked the idea of eating good carbohydrates as she could not imagine a life without carbohydrates at all. She wanted to learn about good oils as she knew there was more to fat than just eat all of it that you want. When she heard about Macademia nut oil, she immediately switched and within a week started to drop the weight and is now thrilled with her new trim, monounsaturated rich self.
Still More Processing
Once oils have been extracted, they have to be filtered to remove any particles before bottling or before they are subjected to further processing or refining. That leaves us with two more categories of oil.
Unrefined – these oils have high nutrient contents and Macademia nut oil is unrefined. However, when buying an oil other than Macademia nut (although I don’t know why you would) since there can be solvents in unrefined oils, always make sure the oil is 100% expeller pressed, if it is unrefined.
Unrefined oils are known for being unstable and having short shelf-lives. This occurs because once the bottle is opened; the fatty acids in the oil will combine with oxygen causing the beginnings of free radical formation and the oil begins to turn rancid. Unrefined oils are not supposed to be used at temperatures greater than 320 F because this temperature can accelerate the free radical damage and the rancidity process. Macademia nut oil does not adhere to this rule since it has large quantities of protective vitamin E, a potent anti-oxidant. Its smoke point can be as high as 410 F. This means it can be used for frying up to that temperature and baking up to 450 F before any free radical formation or rancidity issues occur. Keep this cardinal rule in mind – the more processing an oil undergoes, the more nutritionally compromised it becomes – just like any other food product.
Refined – an oil is refined so that the bioactive components are removed. Therefore, the color, odor, free fatty acids and flavor are essentially removed. This is what is currently being recommended we cook with – a big mistake. The oil has to first be degummed using citric acid to remove the lecithin, a phospholipid. It is then refined with a caustic soda which accelerates the oxidation of the oil creating soap. The oil is then bleached where it is mixed with diatomaceous earth or clay to remove colors and odor. The temperature, at which these processes occur, increases during each step. We are now up to 230 F. The oil is then deodorized whereby steam is blown through the oil under high temperature of 470 F. Oils that contain high amounts of waxes or stearines are then winterized to reduce cloudiness. The oil is cooled to around 45 F and these particles will become solids and the oil is then filtered. BHT or BHA is then added as a preservative. Some oils even add methyl silicone which acts as a defoamer. Clearly, it is important to avoid any oil that has had any of this done to it. When you buy canola oil, safflower, corn, most commercial oils that you probably now have in your cupboard, or any oil that is not 100% expeller pressed oil, this is what you are getting. Throw them away right now before reading any further, they will surely kill you.
Although there are some unhealthy saturated fats, there is another category of fats which is far more dangerous. Trans-fatty acids can be the worst fat for your cardiovascular system and may also increase the risk for breast cancer. These are man-made molecules that are produced during the hydrogenation of vegetable oil. The largest offender in this category is margarine. But, these hydrogenated fats are found almost ubiquitously in our common everyday food environments. Look on any packaged food you have in your cupboard and you will find a hydrogenated fat. Simply look for the words, “partially hydrogenated” in the ingredients list and that is your culprit. The other food categories to broadly ignore are fast foods and vegetable shortening. Sometimes the manufacturer will only say vegetable shortening without the partially hydrogenated moniker – don’t be fooled, it is the same thing. Avoid it.
That is only part of the story. There are over 42,000 foods on the American market which contain trans-fats. They are found in 40% of prepared foods, including cookies, crackers, chips, pastries, breakfast cereals, granola bars and microwave popcorn to name a few, according to the United States Department of Agriculture. They are also found in some frozen foods, such as pies and waffles.
Stick margarine is one big trans-fatty acid. Hydrogenated fats and partially hydrogenated oils are used, in part, to increase the shelf life of snacks and mostly because they are cheap. These are the most harmful fats in our diet as they have been shown to increase the LDL or bad cholesterol and they do not increase HDL or good cholesterol, which cleanses arteries. Food manufacturers have not been required to list trans fats on the food label; but, this that is going to change in 2006. Not a moment too soon since they are the most unhealthy fats we are consuming. Because the government has been so slow to require this on food labels, there are lawsuits starting to be filed by health conscious concerns. One lawsuit even goes so far as to call for the banning of Oreos in the state of California as a health risk. Great concept but it doesn’t go far enough.
Some food manufacturers like Kraft and Frito-Lay, have stated that they are going to voluntarily start decreasing the amounts of trans fats in their products. They are worried about large law suits like the ones that roiled the cigarette industry. My only question is why did it take them so long? They had to know these types of fats were killing us. The FDA estimates that the change in regulations will save between $900 million and $1.8 billion a year in medical costs, lost productivity and pain and suffering. When as little as two to three grams of trans fats per day can increase health risk (as an example, a doughnut has four grams), we are facing a serious dilemma as to how to change how we eat.
The New York City Board of Education recently announced that they were going to reduce the fat in their school lunches because of the fact that 21% of third and sixth graders were obese. Also, almost 15% of the kids in certain neighborhoods had type II diabetes. Even worse, in the most recent study of NYC public schools, 43% of all kids were overweight. While these statistics may be startling, to put this into perspective, in the 1960’s, only 4% of children had a weight problem.
Trying to stem this problem is a good effort, the focus on removing fat is wrong. The focus should be on eliminating trans fats. To show you just how rampant trans fats are here is a look at some of the food that are children are being served and the amount of trans fats in each one:
|Total Fat||21.2 gms||20 gms||17 gms.|
|% Trans Fats||46%||69%||42.5%|
*Source: New York City Department of Education
While saturated and unsaturated fats occur naturally, made by plants or animals, most trans-fats come from factories. Trans fat is formed when liquid vegetable oil is turned into a solid, commonly in the manufacture of margarine or shortening. The consumption of trans-fats started to rise in the 1940’s during World War II when butter and lard were in short supply. Many of the older readers of this book can recall what margarine looked like when it was bought at that time. It was delivered as a grey brick to which you had to add in your own coloring (which was supplied) in order to get it to look palatable. In the 1960’s, its use rose again because consumers were worried about the dangers of saturated fats.
Although trans-fats help make cookies and crackers flaky and keeps potato chips from quickly turning rancid and fast food is routinely fried in it, more and more studies have suggested that trans-fat is bad for the arteries. According to Dr. Walter Willett of Harvard, “trans-fat is many times worse than saturated fat on a gram-for-gram basis.”
Dr. Willett published a study on trans fats which showed that women with the highest intakes of trans fat were 50 percent more likely to be diagnosed with heart disease than women with the lowest intakes. This study appeared in 1993 but with very little fanfare and public outcry. Subsequent studies also showed that trans fats were causing heart disease; yet, most people still don’t know how much of it they are eating because it is not yet required for food labels. Given the standard American diet, it is likely that intake hovers at around 40 grams per day, with fast food and junk food eaters much more than that.
A landmark study by Dutch researchers Mensink and Katan found that margarine consumption increased coronary heart disease. When Willett separated out the trans fat component of the diet in the Nurses Study, he was able to confirm there were greater rates of cancer in those consuming margarine and vegetable shortening, not butter, eggs, cheese, or meat. Mary Enig was also fundamental to this change as her research was often cited by Willett.
Although this research didn’t start to make news until the mid 1990’s, there was evidence to suggest this way back in 1969, when it was discovered that the use of corn oil caused an increase in atherosclerosis. In 1971, the director of the famous Framingham Heart study warned against too many polyunsaturated fats in the diet; someone from the American Heart Association issued a similar warning and the studies on polyunsaturated fats causing an increase in breast tumors also went ignored. The food processing industry combined with the powers-that-be at the federal government was just too powerful at suppressing this information. They were hell-bent on making saturated fats and red meat the culprit for heart disease and they won out for many years, until now.
There have been many studies that can be found in the literature that speak to the dangers of trans fatty acids. Trans fats have been implicated in heart disease, cancer, increasing the likelihood of developing diabetes, decreased testosterone production, abnormal sperm, altered gestation, low birth-weight babies, and consumption of trans fats interferes with the body’s use of omega-3 fatty acids, leading to impaired prostaglandin production. For years, all fats were lumped together when looking at disease rates with the emphasis being on the health risks of saturated fats. Trans fats were actually touted as healthy as was margarine since neither were saturated fats. They were promoted as heart-healthy. All of those low fat foods with billions of dollars in sales, were riddled with trans fatty acids. All this was occurring while at the same time; natural foods that have been with us since the dawn of creation were being derided as unhealthy. That tide is fortunately turning, but not fast enough.
Additionally, most of the trans fats in modern hydrogenated fats are new to the human physiology and their rise in consumption has paralleled the increase in both heart disease and cancer. If that is true, then the government has fostered this epidemic by encouraging the use of the wrong types of fats, villainizing real foods with natural fats, and publicly deriding those who tried to tell a different story. Given the data, it seems clear that the message ought to be to eat natural fats; oils that are highest in monounsaturated fat like Macadamia nut oil and, butter instead of margarine; yet, there continues to be a dramatic rise in the consumption of polyunsaturated vegetable oils.
To quote Dr. Willett again, he states, “I think people shouldn’t try to think of this as a trade-off between saturated fat and trans fat – what you really want to go for is unsaturated fat.” Macadamia nut oil is the gold standard of unsaturated fat. It is monounsaturated rich and is not processed except in the minimal way that anything has to be processed to give us oil. This is the key to the Hamptons diet – the encouraged use of monounsaturated fat coupled with a preponderance on naturally occurring foods. It is the key to 21st century health.
Since food labels won’t be required to list how many grams of trans fatty acids on in a product until 2006, you may not know how many grams you are getting in any particular food. However, skilled label sleuths can figure it out. If the Nutrition Facts box lists saturated fat, polyunsaturated fat and monounsaturated fat, it is quite easy to figure out. Simply total up the grams from those three and subtract from the total fat grams. The difference is the amount of trans-fats. Macadamia nut oil has no trans fatty acids.
If the Nutrition Facts box only lists total fat and saturated fat (since that is required by law), turn to the ingredient list and look for those words, “partially hydrogenated, or vegetable shortening”. That signals that there are trans fats, but it still won’t tell you how much.
|Trans Fat in One Serving of Selected Foods
*Source: United Stated Department of Agriculture
Betty, a 52 year old woman also asked to be included in the success stories of patients because she couldn’t believe how easy it was to lose weight and reduce her menopausal symptoms when she started this program. She had been trying to lose those same 25 pounds since she was 45 and had been unsuccessful on any diet she had tried. At 50, she started to experience severe hot flashes, memory loss, and mood swings as she really started to go through menopause. And, of course, she couldn’t lose weight although Betty had done everything from starvation to Atkins. In the first two weeks, Betty lost 7 pounds on the Hamptons diet, and after the first month her hot flashes diminished to less than once per day. “I know it’s because I am now monounsaturated rich!” Betty got rid of all of the packaged and box foods she was addicted to, started to use Macadamia nut oil exclusively in her kitchen and she began to feel so much better and the weight just poured off.
This is the process whereby the polyunsaturates which are normally liquid, are turned into solids at room temperature. Crisco is an example of this type of fat. The oils that are used in this process are generally the cheapest ones – soy, corn, canola. These have already been damaged by the extraction process so they are unhealthy to begin with. They are then mixed with tiny metal particles, usually nickel oxide. The oil is then heated to a very high temperature. Emulsifiers and starch are then squeezed into the mixture to give it a better consistency. It is then steam cleaned to remove the unpleasant odor and bleached. Artificial flavors and colors are added and then it is ready for the supermarket shelf.
During this heating process, the chemical structure changes. This is where these products get the name “trans.” The hydrogen atom switches the side it naturally occurs on, and is now located in the “trans” position. These fats take their name from this chemical aberration. This configuration allows the oils to become compactable and hence they can become solids. This was originally invented in the late 1800’s and came to the United States in 1909 because butter melted on hot days and refrigeration wasn’t readily available at that time and a need for an un-meltable shortening was filled.
This process was originally used for cottonseed oil. After the Second World War, technological advancements were made which made it possible to apply this same procedure to corn and soybeans. Corn oil and soybean oil is even more unsaturated than cottonseed oil, making it cheaper to process. Soybean oil results in a 40% trans fat product. Cottonseed oil made a 35% trans fat product, corn oil only 25% trans fatty acids and the winner of this dubious unhealthy contest is canola oil which makes a product that is 50% trans fats. Canola oil is a dubious product at best and an entire chapter will be dedicated to undoing all the positive press this unhealthy product has received.
While smoke points, flash points and fire points are terms that are used interchangeably, they are different. A smoke point of an oil or other fatty material is a measure of its thermal stability when heated in contact with air. This is the temperature at which smoke is first detected in a special laboratory apparatus protected from drafts. The temperature at which an oil will smoke freely is usually somewhat higher. This is the temperature to which an oil can be heated before it smokes and becomes discolored which is the visual indication that the oil is decomposing.
The flash point is the temperature at which the volatile products of the oil are produced and the fire point is the temperature at which the oil will turn to flame – sort of like Fahrenheit 451 – that great science fiction thriller which describes the flame point of books.
For typical fats with a free fatty acid content of about 0.05% which is the free fatty acid content of Macadamia nut oil, the smoke point is around 410 F; the flash point is around 620 F and the fire point is around 670 F. Oils containing fatty acids of low molecular weight have lower smoke, flash, and fire points. Oils that are subjected to extended use will have increased free fatty acid contents which results in a lowering of the smoke, flash, and fire points. That means you should never reheat your cooking oils – use them only once – any attempt to save money this way will be a very poor investment in terms of your health.
High heat can cause degradation of the oil that will not only decrease the flavor of the food you are cooking in it, but can cause harmful free radicals to form. The smoke point of any particular oil is very significant and should thoroughly convince you to make that switch to the oil of choice for the Hamptons diet – Macadamia nut oil. Smoke points of various oils will be discussed in a further chapter. Simply keep the heat of the oil you use to a temperature low enough so that you never see smoke rising from the pan.