We need fats because they provide essential fatty acids and help us to absorb Vitamin A, D and E, but we need to make sure we know the difference between good fats and bad fats.
Good fats are monounsaturated fats and polyunsaturated fats. Polyunsaturated fats and monounsaturated fats both have lower melting points than saturated fats. Foods containing monounsaturated fats and polyunsaturated fats are good sources of essential fatty acids. We call these acids essential because the body cannot produce them itself, thus they must be consumed.
Sources of monounsaturated fat are: olive oil, canola oil, high oleic sunflower oil, avocados, cashews, pecans, almonds, and peanuts.
Sources of polyunsaturated fat are: soybean oil, corn oil, sunflower oil, salmon, mackerel, smelt, herring, trout, fish oils, flax seed, sunflower seeds, soybeans, and walnuts.
Saturated fats are fatty acids that are fully saturated with hydrogen atoms. This is why they have a higher melting point and are more difficult for the body to break down. Saturated fats increase both good and bad cholesterol levels.
Sources of saturated fats are: coconut, palm oil, animal fats, butter, cheese, and other dairy products.
Trans fats only occur naturally in small amounts, however trans fats are also created by hydrogenating fat. When fats are partially hydrogenated trans fats are created. Trans fats raise bad cholesterol and lower good cholesterol levels. This is why packaged foods are now required to contain less than 1 gram of trans fats per serving.
The fear of consuming trans fats was largely directed at the restaurant industry which had been using partially hydrogenated fats in fryers. Partially hydrogenated oils were used because they last longer. Now restaurants have changed their cooking methods and use different oils for frying that contain only trace amounts of trans fats that are created during the oil refining process.
The issue of trans fats has mostly been resolved, but now we are confronted with a new problem. It has been discovered that a toxin is released when heating oils to high temperatures. This toxin is called 4-hydryoxy-trans-2-nonenal. Researchers have found that this “…toxin with known connections to heart disease and neurological disorders accumulate in vegetable-based cooking oils that are heated or reheated for hours at a time…”(http://www.healthywomen.org/resources/womenshealthinthenews/dbhealthnews/reheatingvegetableoilreleasestoxinstudy). For this reason it is recommended that when frying foods at home the oil is only used once and that we avoid eating fried foods at restaurants. Exposure to the toxin HNE has been linked to an increased risk of “cardiovascular disease, stroke, Parkinson’s, Alzheimer’s, Huntington’s disease, liver ailments and…cancer”(http://www.healthywomen.org/resources/womenshealthinthenews/dbhealthnews/reheatingvegetableoilreleasestoxinstudy).
Researcher A. Saari Csallany stated that "HNE’s toxicity is that it reacts very energetically with biomolecules…it reacts with the various kinds of amino groups — proteins, DNA, RNA, affecting basic cellular processes.”
This article is a little bit random but this is where my research lead me. I never would have thought that some sources of fat are actually toxic!
It is best to get essiental fatty acids from whole foods, fish, and oils in the form of salad dressing.
