There seems to be a lot of confusion on what is a healthy fat. We now know that trans-fats like margarine or shortening at to be avoided, but there are still other fats that are available which are still very unhealthy to consume, Yet people still think they are doing themselves good by using these fats. Avoiding damaged fats while following the Paleo diet is extremely important.
Which fats to avoid and why
The list of vegetable fats and oils to eliminate from your diet is not terribly long.
- Canola (from rape seed)
Why these oils? These are polyunsaturates. These particular oils contain an excess of omega-6 fatty acids and not enough omega-3. Getting too much omega-6 can cause blood clots, inflammation, high blood pressure, digestive upsets, depression of the immune system, sterility, cancer and weight gain.
During processing the oils are subject to heat, moisture and oxygen. They oxidize, and become rancid.Then they become free radicals, attacking cell walls, red blood vessels and then damage DNA strands. This causes mutations in the body which means premature aging and wrinkles. Enough damage will cause cancer, and the build up of arterial plaque, thus causing heart disease. Free radicals have also been linked to arthritis, Alzheimer’s, cataracts and more.
The processing of the oils is also toxic.From the Weston A Price website:
Oils naturally occurring in fruits, nuts and seeds must first be extracted. In the old days this extraction was achieved by slow-moving stone presses. But oils processed in large factories are obtained by crushing the oil-bearing seeds and heating them to 230 degrees. The oil is then squeezed out at pressures from 10 to 20 tons per inch, thereby generating more heat. During this process the oils are exposed to damaging light and oxygen. In order to extract the last 10% or so of the oil from crushed seeds, processors treat the pulp with one of a number of solvents—usually hexane. The solvent is then boiled off, although up to 100 parts per million may remain in the oil. Such solvents, themselves toxic, also retain the toxic pesticides adhering to seeds and grains before processing begins.
High-temperature processing causes the weak carbon bonds of unsaturated fatty acids, especially triple unsaturated linolenic acid, to break apart, thereby creating dangerous free radicals. In addition, antioxidants, such as fat-soluble vitamin E, which protect the body from the ravages of free radicals, are neutralized or destroyed by high temperatures and pressures. BHT and BHA, both suspected of causing cancer and brain damage, are often added to these oils to replace vitamin E and other natural preservatives destroyed by heat.
Then there is the process of hydrogenation. This process turns normally liquid fats to solids at room temperature. These oils are even worse for you. Again from the Weston A Price website:
To produce them (hydrogenated fats), manufacturers begin with the cheapest oils—soy, corn, cottonseed or canola, already rancid from the extraction process—and mix them with tiny metal particles—usually nickel oxide. The oil with its nickel catalyst is then subjected to hydrogen gas in a high-pressure, high-temperature reactor. Next, soap-like emulsifiers and starch are squeezed into the mixture to give it a better consistency; the oil is yet again subjected to high temperatures when it is steam-cleaned. This removes its unpleasant odor. Margarine’s natural color, an unappetizing grey, is removed by bleach. Dyes and strong flavors must then be added to make it resemble butter. Finally, the mixture is compressed and packaged in blocks or tubs and sold as a health food.
Partially hydrogenated margarines and shortenings are even worse for you than the highly refined vegetable oils from which they are made because of chemical changes that occur during the hydrogenation process. Under high temperatures, the nickel catalyst causes the hydrogen atoms to change position on the fatty acid chain. Before hydrogenation, pairs of hydrogen atoms occur together on the chain, causing the chain to bend slightly and creating a concentration of electrons at the site of the double bond. This is called the cis formation, the configuration most commonly found in nature. With hydrogenation, one hydrogen atom of the pair is moved to the other side so that the molecule straightens. This is called the trans formation, rarely found in nature. Most of these man-made trans fats are toxins to the body, but unfortunately your digestive system does not recognize them as such. Instead of being eliminated, trans fats are incorporated into cell membranes as if they were cis fats—your cells actually become partially hydrogenated! Once in place, trans fatty acids with their misplaced hydrogen atoms wreak havoc in cell metabolism because chemical reactions can only take place when electrons in the cell membranes are in certain arrangements or patterns, which the hydrogenation process has disturbed.
There is a correlation between cancer and the consumption of hydrogenated fats. These trans-fats block our bodies from using essential fatty acids, causing, among other things, an increase in cholesterol levels. Trans fats are also associated with:
- Immune system dysfunction
- Birth defects
- and more….
The best thing to do is to just avoid trans fats. Check the labels for hydrogenated or partially hydrogenated fats. It is also best to avoid using the polyunsaturated oils listed above, and avoid them in packaged foods. Again read the ingredients label. Don’t rely on the government’s nutritional label.
I have addressed some of the issue of what oils you should use in other posts: here, here and here. In the future I will write more extensively on which oils to use and why. At least we know which damaged fats to avoid while on the Paleo diet.