COOKING WITHOUT OILS

Why it is Important to Cook Without Heated Oils

Food companies have come a long way in their ability to improve the properties of vegetable oils at the manufacturing level. There are refined and conditioned oils in the marketplace, including oils from plant hybrids that are high in certain types of fat such as monounsaturated fatty acids, which are less susceptible to damage from heating (high-oleic safflower oil is one example). If you are going to cook with oils, your best bet are these organically produced, high quality oils that have been specifically adapted for use in high heat cooking or oils that have naturally high smoke points, like avocado oil. But I believe you have an even better option—cooking without oils!

Heating Oils 

When you heat a highly unsaturated oil like safflower or sunflower oil, it will start to smoke at a fairly low heat—in the vicinity of 225°F (107°C); this is called its smoke point. When manufacturers refine these oils, they can increase the smoke point by about 100–125°F (38–52°C). In the case of refined safflower or sunflower oil, the heated oils won’t smoke until about 325–350°F (163–175°C). With a monounsaturated oil like canola oil, however, refinement can raise the smoke point to about 400°F (204°C). Manufacturers of extra virgin olive oil claim smoke points of anywhere from 200°F (93°C) to 405°F (207°C), depending on the degree of refinement and original condition of the oil. Refined avocado oil—an oil that is naturally 12% saturated and 72% monounsaturated—has one of the highest smoke points of all vegetable oils at 520°F (271°C).

When you heat an oil to its smoke point, you have definitely inflicted a good bit of damage to the oil. This damage comes in several form.

DAMAGE TO NUTRIENTS IN THE OIL 

• Heating causes loss of available nutrients contained in oils, including fat-soluble vitamins like vitamin E and the phytonutrients that give oils their characteristic colors, smells and flavors.

• Heating oils can cause the formation of free radicals, highly reactive molecules that can damage the oil further by triggering unwanted oxidative reactions. Oil manufacturers actually assign a value (called a peroxide value, or PV) to the oils based on the amount of oxidative reactions occurring.

• Formation of unwanted aromatic substances (like polycyclic aromatic hydrocarbons, or PAHs) in the oil that can increase our risk of chronic health problems including cancer.

The smoke point is a natural property of unrefined oils, reflecting their chemical composition. When oil is refined, the process increases the oil’s smoke point; in fact, raising the smoke point is one of the reasons why the refining process is used. To get a better idea of how refining increases the smoke point of oil, look at Table 1 on the next page, which shows several examples.

Olive Oil and its Smoke Point 

You will see various types of olive oil on the market:

• EXTRA VIRGIN: derived from the first pressing of the olives and has the lowest acidity level.

• FINE VIRGIN: also created from the first pressing of the olives, but it has an acidity level more than double that of extra virgin oil.

• REFINED: unlike extra-virgin and fine virgin olive oils, which only use mechanical means to press the oil, refined oil is created by using chemicals to extract the oil from the olives.

• PURE: a bit of a misnomer, it indicates oil that is a blend of refined and virgin olive oils.

Unlike the information presented in Table 1, the information on olive oil’s smoke points is, unfortunately, not very clear or consistent since different companies list different smoke points for their olive oil products; this variability most likely reflects differences in degree of processing.

Generally, the smoke point of olive oil falls in the range of 220–437°F (104–225°C). Most commercial producers list their pure olive smoke points in the range of 425–450°F (218–232°C), while “light” olive oil products—which have undergone more processing—are listed at 468°F (242°C). Manufacturers of extra virgin oil list their smoke points in a range that starts just under 200°F (93°C) and extends all the way up to 406°F (208°C). Again, the variability here is great and most likely reflects differences in the degree of processing.

In principle, organic, unrefined, cold-pressed extra virgin olive oil should have the lowest smoke point of all forms of olive oil since it is the least refined and most nutrient-rich, containing the largest concentration of fragile nutritive components. For a natural, very high-quality extra virgin olive oil, I believe the 200–250°F (93–121°C) range reflects the most likely upper limit for heating without excessive damage. In other words, this would allow the use of extra virgin olive oil for making sauces but not for 350°F (175°C) baking or higher temperature cooking.

On my last visit to Italy, I visited many homes and restaurants to find how extra virgin olive oil was used in cooking. What I found was they don’t use extra virgin olive oil for cooking; they use safflower oil or refined olive oil because of their high smoke point.

Cooking Without Heated Oils—“Healthy Sauté”

If damage to oils only occurred at smoke point, I might be more comfortable with the idea of using oils when cooking. However, oil can be damaged from heat long before its smoke point is reached. Exactly when does damage start to occur? The research is not entirely clear about this point. Very low heating of soy oil, for example, at temperatures below 160°F (71°C), does not appear to cause many oxidative reactions even if prolonged for the course of an entire day. However, 160°F (71°C) is hardly hot enough for stove-top cooking. Water boils at 212°F (100°C). Damage seems to vary between 175°F (79°C) and the oil’s smoke point—depending on the specific oil and its processing. However, even with a refined and relatively saturated oil, nutrient changes and oxidative reactions begin to occur well before the smoke point is reached.

For the reasons above, I believe it is best not to cook with heated oils. While steaming is a popular cooking method that doesn’t use oils, I have created another low-heat alternative that I call “Healthy Sauté.” This method was developed specifically to avoid unnecessary heating of vegetable oils by using broth instead of oil.

I have been using this technique for over 10 years with great results. Adding extra virgin olive oil to vegetables, sauces and soups after they have been cooked not only prevents the oil’s exposure to high heat but allows you to enjoy more of the oil’s wonderful flavor. All of the recipes in this book cook foods without the use of heated oils. I think you’ll like the results in terms of flavor as well as nourishment!




By George Mateljan in "The World's Healthiest Foods - Essential Guide for The Healthiest Way of Eating", George Mateljan Foundation USA, 2007, excerpts part 3. Adapted and illustrated to be posted by Leopoldo Costa.