Polyunsaturated oils or vegetable oils, are inherently unstable. When in contact with heat, light and/or oxygen it will breakdown and go rancid producing free radicals that are a significant source of oxidative stress. While this is scientifically known, we are still encouraged to not only consume them but use them for cooking purposes. It really makes no sense from a health perspective.
Before any canola (rapeseed), soybean, corn, cottonseed or other “vegetable” oil makes it to your table it has to go through an interesting process.
Extraction: The fats or oils first must be extracted. Traditionally this was done by hand with a slow moving stone process. Today, oils are processed by crushing the oil-bearing seeds and heating them to 230° Fahrenheit. The oil is then squeezed out at pressures from 10-20 tons per inch which generates more heat. The oils are also exposed to damaging light and oxygen. To extract the last 10 percent of the oil, processors treat the pulp with one of a number of solvents, usually hexane. Hexane, if you are not aware, is a petroleum by-product and neurotoxin. The solvent is boiled off, although up to 100 parts per million may remain in the oil. These solvents also retain the toxic pesticide residue that was adhered to the grains and seeds before the processing began.
Not only does this process create damaged free radicals, any antioxidants such as Vitamin E which combat free radical damage are neutralized or destroyed by the high temperatures and pressure.
There is a safe modern method of oil extraction that drills into the seeds and extracts the oil and its antioxidants under low temperatures with minimal exposure to light and oxygen. These expeller-expressed, unrefined oils will remain fresh if stored in the fridge in dark bottles. While they are better options than your standard vegetable oil, they are still polyunsaturates and should not be heated.
Hydrogenation: This process is used to turn a polyunsaturate which is normally liquid at room temperature into a solid at room temperature. Your primary examples of this are margarines and shortening. Typically used are the cheapest oils available, soy, corn, cottonseed or canola that are already rancid from the extraction process. They are then mixed with tiny metal particles, usually nickel oxide. This oil metal blend is subjected to hydrogen gas in a high pressure, high temp reactor. Then they squeeze soap-like emulsifiers and starch into the mixture to improve the consistency. The oil is yet again subjected to high temps when steam cleaned to remove unpleasant odors. Margarines natural color is an appetizing grey (insert sarcasm). That is removed by bleaching. Dyes and strong unnatural flavors are added to make it resemble butter. They finish by compressing the mixture into shapes and tubs to be sold as health food.
All that to make something that appears like and tastes like butter. Why not just consume the real thing that is actually good for you?
Trans Fat: Partially hydrogenated margarines and shortenings are also worse than the highly refined vegetable oils because during this hydrogenation process changes to the chemical bonds take place creating a “trans” formation. This man-made trans fat is toxic to the body, but your digestive tract does not recognize them as such so they are allowed in and incorporated into cell membranes as if they were saturated. In essence, your cells become partially hydrogenated. Trans fatty acids wreak havoc with cell metabolism and cell wall function due to their unnatural chemical structure.
During the 1940’s researchers discovered this strong correlation between cancer and the consumption of fat, specifically trans fat from the hydrogenated sources which they used in their studies. They assumed the culprit was saturated fat….they were wrong. Unfortunately most of the general public does not realize this and marketers and big agribusiness use this to their advantage.
Real Animal Fats: For comparison purposes, lets look at the process involved to make two common and traditional fat products, Lard and Butter.
Lard is essentially rendered pork fat. There are two types, back fat and leaf lard. Leaf Lard is the fat from around the kidneys and ideal for baking. While they are from different locations they are rendered the same. First remove the skin from the back fat and place in a non-reactive pot (stainless steel) with a lid and a small amount of water. Bring to a low simmer, stirring occasionally until the fats starts releasing then leave it alone for anywhere from 6-12+ hours. Once done, strain it and place into jars. You can freeze the lard for later or keep in the fridge for many weeks to months depending on how readily you use it.
Butter is derived from cow’s milk, specifically the cream that separates and floats to the top of raw milk (non-pasteurized). These instructions are just the basics. You can “ripen” the cream by allowing it to sit unrefrigerated. You then either shake or churn the cream for about 15 to 30 minutes or until you see a separation of the buttermilk from the butter. Strain the buttermilk away and save for other yummy recipes. While the solids are still in the strainer rinse thoroughly with cold water. Once you have removed any excess water sprinkle it with salt, work it in until evenly combined and you are done.
If you tend to butter your toasted bread, the ideal amount of butter to use is enough that when you take a bite, you leave tooth impressions in the butter. Anything less is just not good enough.
As you can see, the process required to turn a plant into an oil that is edible but not healthy, is very intensive. Even considering the technology required, the end product is still inexpensive. When you combine the price with excellent marketing by both food corporations and our government you can see why it is so prevalent in the food industry.
Rendering lard or making butter is a rather simple process and minimally processed. You can make real fat at home without a laboratory and manufacturing plant. Plus you get to enjoy taking a hands on approach to building a healthier you.
If you wish to try an experiment, when you go out to eat, ask your server what type or oil or fat the food is cooked in……….