Talk about confusing! With all of the oils available now, it’s hard to know what to buy, and even harder to know what to use for cooking. Before I start talking about cooking oils and health, I want to clarify that all oils are healthier when not exposed to heat of any kind. All fats begin to break down with exposure to air and light as well. Therefore, it is best to use any fat when it is freshest.
Having said that, there are distinct differences between fats that make some healthier for cooking than others. The main factor used to determine this, called the “smoke point”, is the temperature at which any given fat begins to smoke and burn. Smoking and burning is the visible sign that the fat molecules are degrading, which translates to stinky, bad-tasting food that is not good for you! If you look for smoke points of varous fats, you will find that they vary depending on the source of your information.
Many factors influence the smoke point of any given fat, including degree of freshness, purity, processing, and exposure to air or light. The smoke point decreases as any fat degrades. As an example, high quality extra-virgin olive oil will have a higher smoke point than one that has been sitting in the sun with the cap off for a long time.
So, which fats are healthier to cook with? Olive oil and other monounsaturated fats are relatively stable and are good choices. This includes peanut, canola, grapeseed or avocado oil. The smoke point for olive oil seems to vary from about 375-405 degrees F. This is high enough to allow most stovetop cooking with minimal degradation. Since monounsaturated fats like olive oil are considered good choices for heart health, it is comforting to know that they also hold up well to moderate heat.
Butter has a relatively high smoke point (about 350 degrees F), since it is a saturated fat and therefore relatively stable. The problem with butter is that it has a high content of milk solids, which burn easily and cause smoking. Clarified butter is butter with the milk solids removed, so it works better than regular butter for cooking at higher temperatures. (Wow! – Say that 3 times fast!) Still, as with all saturated fats, butter should be limited to promote heart health.
I recommend cooking with olive oil and/or small quantities of butter (adds great flavor). Remember that cooking at a lower heat will produce less damage to the fat used. For even healthier cooking, food can be steamed or poached instead, and then tossed with oil or butter before serving.