The best oils for cooking

There is a lot of misinformation and confusion surrounding the topic of the best oils to use for cooking. Mainstream media continues to promote polyunsaturated oils as healthy and continues to demonize coconut oil. But they have it wrong and here is why…

So what are the best oils for cooking?

When you are cooking at high temperatures, you want to use oils that are stable and do not oxidize or go rancid easily. When oils undergo oxidation, they react with oxygen and can form free radicals. There are four types of fatty acids: saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA), which includes omega-3 and omega-6 fatty acids, and lastly, trans fatty acids (TFA).

What defines the type of fatty acid is their chemical structure. The most stable are saturated fats, which are solid at room temperature. These fats include coconut and palm oils. Coconut oil has been demonized because we have been told that the saturated fats we eat become saturated fats in our blood. But the shocking counterintuitive fact is that dietary saturated fats do not raise blood saturated fats. Dr. Mark Hyman in his book Eat Fat, Get Thin reminds us that it is refined “carbohydrates and sugar that cause the liver to produce the saturated fats found in the blood." Coconut oil actually has powerful medicinal properties and it is a medium-chain fatty acid that is easily digested and absorbed by the cells and used for energy.  Oils from saturated fats do not normally go rancid and they are great for both cooking and baking.

​Monounsaturated oils are liquid at room temperature, but become solid if refrigerated. These include olive oil, peanut oil, and avocado oil. These are relatively stable. They do not go rancid easily and can be used in cooking. Olive oil, known for its heart-healthy effects, is ideal for salads and can also be used for cooking at moderate temperatures. Extra virgin olive oil is rich in antioxidants and is one of the safest oils that you can use. Peanut oil is relatively stable and is ideal for stir-frying. Avocado oil is similar to olive oil and can be used in cooking at high temperatures or in salads. 

Polyunsaturated oils are always liquid, even when refrigerated. These oils include corn, soy, safflower, and sunflower. They go rancid easily and should not be heated or used in cooking, frying, or baking.  These oils are known as vegetable oils, but this does not mean that they equate to a serving of greens in any way, shape, or form. The refining of these oils ultimately destroys both the healthy polyunsaturated fatty acids and their antioxidants and converts them into distorted, unhealthy molecules. Dr. Shanahan in her book Deep Nutrition explains that vegetable oils are processed much like motor oil. She explains that the tiny seeds are pressed with intense pressure and heat and that one of the initial steps involves the use of hexane, a component of gasoline. This produces a nasty smelling oil, so it takes another 20 or so additional steps to bleach and deodorize this “dark muck."

Although canola oil is a monounsaturated oil, it is in a category of its own due to the harsh processing method it entails. Although canola oil is still considered “healthy” by the media and certain organizations, it is a highly refined product. The health claim comes from the fact that canola is rich in anti-inflammatory omega-3 fatty acids – and it is, in the seed form (canola comes from the rapeseed). The omega-3 fatty acids are polyunsaturated and are easily distorted when exposed to heat; and during the deodorizing process, these omega-3 fats are transformed into trans fatty acids. Dr. Shanahan posits, “factory processed canola, even organic expeller pressed, contains mutated, oxidized, heat-damaged versions of once-healthy fats." What was once healthy in the seed is no longer healthy in the liquid form.

​Trans fats are the very worst fats for our cells because these toxic fats can lead to the formation of free radicals. Free radicals can cause damage to any part of the body. Trans fats are stiff and hard and literally embed themselves into our cell membranes, causing them to malfunction and create disease. Trans fats are man-made and found in processed foods, shortenings, margarines, fried foods and commercially produced baked goods. Nature does not produce bad fats – factories do! They are not safe to eat and were declared as such in 2013 by the FDA. However, buyer beware: a product that is labeled “no trans fats” can still contain up to 0.5 grams of trans fats per serving. These fats do not belong in your diet! 

Dr. Mary Enig, a nutritional biochemist, has been warning us of these toxic fats since the 70s. If you are interested in an exposé of the false demonization of natural fats and the misinformation of low-cholesterol diets rich in crop oils, check out Dr. Enig’s work called The Oiling of America. It is a 2-hour lecture presented by Sally Fallon, founding president of the Weston A. Price Foundation. It is extremely interesting and traces the intertwining of certain influential scientists with the crop oil industry. ​

​Take away – stick with saturated fats and monounsaturated fats, not polyunsaturated for cooking and baking. And to ensure that your oils do not go rancid:
1. Don’t buy in large quantities. Buy smaller bottles (preferably dark-colored glass with a tight-fitting cap) that you will use before they can get damaged. Heat, light, and oxygen can damage oils.
2. Keep oils in a cool, dry, dark place.

Sources:
Fallon, S. (2001). Nourishing traditions. Washington, DC: New Trends Publishing.
Hyman, M. (2016). Eat fat, get thin. New York, NY: Little, Brown, & Company.
Shanahan, C. & L. (2009). Deep nutrition. Lawai, HI: Big Box Books.