Oil Confusion: Healthiest Oils & Their Heat Limits
Some oils are better for you than others. But even a healthy one, such extra-virgin olive oil (EVOO), has a heating limitation called a smoke point. Somewhere from 300 to 375 degrees F (depending on the manufacturer), EVOO starts to break down chemically, causing the loss of phytonutrients called polyphenols that provide 99% of the amazing health benefits. If the oil is heated beyond the breakdown temperature and begins to smoke, the smoke may even release disease-causing carcinogenic compounds. In the case of extra-virgin olive oil, people may not realize that there are better alternatives for high-heat cooking methods such as roasting, sautéing, grilling and stir-frying. More refined olive oils such as virgin olive oil and light olive oil can be heated to higher temperatures before they break down, but they don't contain as many health-promoting polyphenols.
Other more heat-tolerant, but still healthy oils include refined safflower oil, Canola oil, avocado oil, macadamia oil, almond oil, refined peanut oil, sesame seed oil, and tea seed oil. Most of these oils, like olive oil (78% MUFAs), contain predominately monounsaturated fatty acids (MUFAs), also known as omega-9 fatty acids, which provide many health benefits. Their heart-protective qualities are supported by substantial scientific research. It appears that monounsaturated fats also help to control blood sugars when used to replace either saturated fats, like butter or refined carbohydrates, like white flour. Exciting research suggests that monounsaturated fats may also reduce the belly fat that drives the vicious cycle of inflammation and insulin resistance (which tends to cause us to accumulate yet more body fat). This lowers our risk for heart disease, stroke, metabolic syndrome, cancer, Alzheimer's disease, and muscle loss.
Oil Options
Safflower oil: Refined safflower oil is a neutral oil that is very high in monounsaturated fats (78%) like extra-virgin olive oil. In contrast to extra-virgin and virgin olive oil, it has the advantage of breaking down only at high temperatures (450-510 degrees F), so you can feel comfortable cooking with it. Don't confuse refined safflower oil with unrefined safflower oil, which is fragile like EVOO and shouldn't be heated. Unrefined safflower oil is predominately polyunsaturated fatty acid. It’s a nice oil but doesn't have the same benefits as the monounsaturated fats or the cooking advantages.
Canola oil: There is a lot of confusion revolving around canola oil, so let me set the record straight. The plant is called canola rather than rapeseed. Canola oil was bred naturally from rapeseed in Canada in the early 1970s, but has a different nutritional profile and contains less erucic acid than rapeseed. This misunderstanding has been the cause of canola oil getting a bad rap. Also high in monounsaturated fats (63%), canola oil has the added benefit of containing healthy omega-3 fatty acid (ALA). Try purchasing organic canola oil to avoid pesticides and genetically modified organisms (GMOs), but stick to the refined product, as it has a higher smoke point of around 400 degrees F. It doesn't have the polyphenols that are destroyed in heat like olive oil, and it has all of the benefits of a monounsaturated fat. In fact, highly processed canola oil was studied in the Canola Oil Multi-Centre Intervention Trial, a large research trial conducted by several universities, which reported that MUFA intake specifically reduced abdominal fat. After four weeks, the participants of this ongoing study lost 1.6% of their abdominal fat by consuming a smoothie high in MUFA, along with a heart-healthy diet.
Avocado oil: The temperature at which avocado oil begins to degrade is about 480 degrees F for unrefined avocado oil and up to 520 degrees F for refined avocado oil, so there are no worries about cooking with it, either. Plus, avocado oil is almost as high in monounsaturated fats (74%) as safflower oil and olive oil and consequently has health benefits. If you are not planning on heating the oil, it is preferable to use the whole fruit form of the avocado rather than just the oil. This way you can take advantage of all the nutrients working together, and lose fewer nutrients from the processing. Blenderize an avocado into a salad dressing rather than just adding the oil to thicken it; this way you can add even more body and creaminess to the finished product. Avocados can replace mayonnaise on a sandwich: cut open the avocado and using a knife, just spread the avocado on like a sandwich spread. This moistens the sandwich, and of course, provides many more nutrients. A little sprinkle of salt makes the avocado flavor come alive!
Macadamia oil: Macadamia oil is also high in beneficial monounsaturated fats (84%), with a favorably high smoke point of 410 to 453 degrees F. This mild-tasting oil goes through minimal processing, so more of the nutrients end up in the oil. Macadamia oil is becoming more popular and thus more available lately despite its high price, so you may be able to find it at your regular grocery store.
Other Nut Oils: With the exception of macadamia oil, almond oil, and walnut oil, tree nut oils are similar in makeup and durability. They are composed of about half monounsaturated fat with a smoke point of around 450 degrees F. Almond oil contains a little more than half monounsaturated fat (62%) and has a higher smoke point of 450 degrees F. Walnut oil is fragile and should not be heated.
Peanut Oil: Although it contains a little less of the fat-fighting, health-boosting monounsaturated fatty acids (48%) than other oils, it does contain small amounts of resveratrol, a compound that may protect against cancer and heart disease. Refined peanut oil can handle temperatures up to about 450 degrees F, while unrefined peanut oil has a lower smoke point, at around 320 degrees F. It is best not to use it for high-heat cooking like stir-frying. Peanut oil adds a lot of flavor to a stir-fry, but ensure that you use the refined version.
Sesame Seed Oil: This oil is made up of about 45% monounsaturated fats and has a smoke point of 450 degrees F for the refined version, and 351 degrees F for the unrefined version. The flavor adds an important element to Asian food but is too strong to be the main oil source of a recipe.
Tea Seed Oil: This lesser-known oil here in the United States is the main oil used in the Southern provinces of China. It's hard to find in a regular grocery store and sometimes is labeled "stir-frying oil" but can be purchased online or at some Chinese markets. The extra effort to buy it may be worth it since it contains about 88% MUFAs with a high smoke point of 486 degrees F and tastes delicate with a nutty-like asparagus flavor. It's light, thin and doesn't leave an oily sheen as viscous oil does.
