In Part 1, I talked about how healthy fats are an important part of the diet and are not behind weight problems, despite our programming that we should replace fats with low-fat and non-fat products. These products tend to be high in sugar and and/or other unhealthy additives and subsequently contribute to weight gain just the same. Although the amount of fat we each require varies biologically from one person to the next, fat is and will always be an important part of a healthy diet, achieving our optimal weight and disease prevention.
I also discussed some of the best oils from a health perspective which include extra-virgin olive oil, flaxseed oil, coconut oil, palm oil, avocado oil, nut oil, sesame oil and sunflower oil (in its raw/uncooked form). The labels you should always look for when choosing oils are extra-virgin, cold-pressed and organic to ensure the highest nutritional value and quality.
Today I’d like to take the discussion one step further and talk about the best oils for cooking and the potential health risks associated with the ones you shouldn’t use. But first and foremost, it’s important to understand what happens to oil when it’s heated at high temperatures and used for frying foods.
When polyunsaturated Omega-6 oils are heated at high temperatures, they are highly susceptible to oxidative damage, which is even more dangerous then consuming trans fats. Trans fats are formed when vegetable oils are hydrogenated to create margarine, shortening and increase shelf life in many packaged foods. Most people are fairly aware that they should avoid these fats at all costs if they want to prevent clogged arteries, heart disease and many other chronic diseases. However, the information that heating these cooking oils can not only produce some trans fats, albeit minimal, but also produce more toxic side effects then the trans fats themselves is enough to convince most people to find another option rather than take the risk.
The cooking oils to be avoided are sunflower, soy, corn, safflower and canola. The fact that canola oil has been marketed as an equally healthy oil to olive oil is deceiving and not true. Canola is actually made from genetically modified rapeseed plants, which is subsidized and cheap to produce. It is has been subjected to high heat chemical processing and deodorization to make it consumable. It often contains trans fats due to the refinement process, and is made up of a long-chain fatty acid called erucic acid, which is toxic in high concentrations. Both the erucic acid content and canola oil’s contribution to Vitamin E deficiency, can negatively impact heart health despite claims otherwise. Even though canola is a monounsaturated fat, it is not a “natural” oil found in nature and should not be used for cooking.
With that said, olive oil is also not your best choice for frying foods. Yes it’s true that olive oil is a more stable monounsaturated fat that isn’t genetically modified or processed like canola oil, it still oxidizes at a high temperature and produces aldehydes, albeit to a bit of a lesser degree and later then the polyunsaturated oils. It should be ok if used for low to medium temperature cooking, but is much better kept for salads, sauces and other raw uses.
So which oil is your best option for cooking? Many health experts will agree that coconut oil is your safest bet. This is because coconut is a saturated fat (a good one with many health benefits in both its raw and cooked form), which protects it from heat damage and the creation of trans fats. Red palm oil is another healthy oil that remains stable at high temperatures due to its saturated fat content, retaining its nutritional properties without any negative health effects. Both coconut and palm oil can be stored for many months at room temperature without becoming rancid, as is the case with many other oils once exposed to air. 
 Mercola, J. (2010, October 30). New warning about olive oil. Retrieved from http://articles.mercola.com/sites/articles/archive/2010/10/30/rudi-moerck-on-cooking-oils.aspx
 All-organic-food.com (No date). Canola oil report. Retrieved from http://customers.hbci.com/~wenonah/new/canola.htm
Sciencedaily.com (2012, February 22). Fried food risks: toxic aldehydes detected in reheated oil. Retrieved from http://www.sciencedaily.com/releases/2012/02/120222093508.htm
 Fife, B. (No date). Red palm oil: a daily dose of vitamins from a cooking oil. Retrieved from http://www.coconutresearchcenter.org/article%20red%20palm%20oil.htm
Published On: November 01, 2012