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Why You Shouldn’t Use Olive Oil in Your Stir-Fry

We all know that certain oils are healthier than others, but oil health goes beyond just the type. It turns out that the health of your oil can be related to how you use it, too. 

Each type of oil has what’s called a “smoke point.” The smoke point is the specific temperature at which the oil starts to break down, or in more technical terms, the point at which its molecular structure begins to change. These molecular changes result in changes in flavor, as well as changes in nutritional value; specifically, the nutritional value of the oil starts to degrade, changing what once may have been considered an especially healthy oil (such as olive or flaxseed, which is rich in omega-3s) into one that is unhealthy. 

The higher an oil’s smoke point, the higher the temperature the oil can withstand. As a result, each type of oil should be used for the cooking method that is most appropriate to its individual smoke point and heat tolerance. Here is a quick guide for the next time you reach for your favorite oil: 

Heat During Cooking: No heat
Oil: Flaxseed
Best Use: Salads 

Heat During Cooking: Low to moderate
Oil: Coconut, corn, olive, peanut, sesame, walnut
Best Use: Baking (low heat), light sautéing, pressure cooking, salads 

Heat During Cooking: Medium heat
Oil: Macadamia nut, safflower, canola
Best Use: Baking (medium heat), sautéing, stir-fry 

Heat During Cooking: High Heat
Oil: Avocado, sunflower, soybean/soy
Best Use: Deep browning, deep-frying, searing 

Note that the above table represents oils that are refined. Most of the oils we buy in stores are refined. These oils tend to have much higher smoke points than their unrefined counterparts. They also differ in nutrition and flavor. Unrefined oils are more nutritious (some of an oil's nutrients are removed during the refining process), and they tend to be much richer in flavor. For instance, unrefined peanut oil will smell and taste just like peanuts, while refined peanut oil will have a lighter smell and taste. 

When it comes to extremely high-heat cooking, always choose oils that are refined. If, however, you are anxious to have a salad with a rich taste, splurge on the unrefined variety if your palate so desires! 

Excerpted from “GET REAL” and STOP Dieting! Copyright 2009, Brett Blumenthal 

Copyright 2009 Lauren Mackler all rights reserved. Coach Lauren Mackler is the author of Solemate: Master the Art of Aloneness and Transform Your Life (Hay House, April 2009) and Speaking of Success with Jack Canfield and Stephen Covey. Visit Lauren’s web site at 

Originally published on SheerBalance

Updated on March 12, 2011