Mono-saturated fats are liquid at room temperature & are known for being high in the antioxidant Vit. E. They are not as stable for cooking, but used best in spreads & dressings or occasional low heat cooking. The most common form is oleic acid & it can be found in: avocados, almonds, canola oil, cashews, hazelnuts, macadamia nuts, olive oil, peanuts, pecans & pistachios.
Hydrogenated oils are highly refined & found in most packaged food. It's a process by which an extra hydrogen molecule is added, therefore able to convert liquid oils to a solid or semi-solid fat, such as margarine. It is beneficial to the manufacturer, but not the consumer because trans-fats are formed in the process. These have been linked to cancer, heart disease & many other chronic degenerative disorders. Trans fats are actually toxic for our cell membranes. With an over abundance the cells become leaky & distorted.
Polyunsaturated fats are the least stable of all fats. They are liquid or soft at room temperatures. They can not withstand a lot of high heat cooking or processing because free radicals are easily formed. Free radicals are compounds that damage the cells of the body. The most common forms of these fats are the omega-6 (linoleic) & the omega-3 (linolenic)!
Sources of omega-3 fatty acids are: cold water fish oils such as mackerel, salmon, albacore, tuna, sardines & lake trout. Flaxseeds & oil. Pumpkin seeds & walnuts.
Sources of omega-6 fatty acids: Borage, black currant, canola, corn, cottonseed, primrose, safflower, soybean & sunflower.
Processed vegetable oils (i.e. refined oils) are very popular in the grocery aisles & in our diets. These oils are overused due to misinformation of their health qualities by the food industry as well as health care providers. They contain high amounts of omega-6 without the balancing effects of the omega-3's & have been shown to suppress the immune system over time.