[Suzanne 3FC]

Mayo Clinic Health Information News
Friday, July 27, 2001

The Skinny on Cooking Oils

ROCHESTER, MINN. -- Cooking with oil doesn’t have to be a fattening experience. In fact, a little fat can be good for you -- if you choose the right kind. The August issue of Mayo Clinic Women’s HealthSource offers a guide to cooking oils.

In terms of calories, all oils are the same. They each contain 9 calories per gram. Don’t be misled by oils that are labeled "light." The word only refers to the taste. Among cooking oils, monounsaturated oils are the best choice. When substituted for saturated fats like lard or butter, they can decrease LDL "bad" cholesterol levels without lowering HDL "good" cholesterol levels.

Olive oil is one of the most popular cooking oils thanks in part to the popularity of Mediterranean cooking. Olive oil burns at high temperatures, so never cook with higher than medium heat. Extra-virgin olive oil is the best bet for recipes that don’t require cooking, such as dressings, marinades or dips. Olive oil comes in many varieties and brands and has a distinct flavor, so shop around for the one you like best.

Canola oil is great for sautéing and salad dressings when you want flavors of the other ingredients to come through. Safflower oil has a very low saturated fat, second only to canola oil. It’s similar to olive oil and is used in stir frys or as a salad oil.

Sesame oil has the pronounced flavor of toasted sesame seeds. It’s used in many Asian and Indian dishes. The flavor doesn’t stand up well to heat, so use it in uncooked dishes or add it at the end of cooking. Peanut oil is also used in a lot of Asian foods. It’s particularly good for stir frying or other techniques that require high heat.
Finally, walnut oil is high in alpha linolenic acid, one of the omega-3 fatty acids which are thought to be protective against heart disease. Walnut oil gives food a distinctive nutty flavor and is especially good on salads.

All of these oils are healthy additions to your diet -- in moderation. Remember that one serving of oil is only one teaspoon. Using a cooking spray made with one of the oils or an oil mister can help control the amount you’re using.

[DreamSmall]

I thought that I read somewhere a few years back that when Canola Oil gets hot that it becomes spoiled and almost like formaldahyde(or something like that)... is that true? I may be confused... the older I get the more likely that is and it was a few years back that I seem to recall reading this.

[TobeyToe]

Here is an article that you may find useful.

Tobey


Q: I recently read that canola oil and other unsaturated oils are not good to cook with at high temperatures. What oils are safe to use for grilling, baking, sautéing and frying?

Mary Murkland, Gulf Breeze, FL

A: Thanks for your important question. Any fat, and oil is a liquid fat, becomes rancid (oxygen denatured) with exposure to heat, light or air. We all know the taste of rancidity. Recall munching a hand full of peanuts and inadvertently swallowing a bad one. Yech! The peanut's rancid fat has a nasty, acrid taste that lingers in your mouth and burns all the way down your throat. Eating a rancid peanut, or old butter, or oil processed at high temperatures, or a food cooked in reused frying oil is toxic. It especially challenges the liver, the primary organ for fat metabolism.

Unsaturated fats high in omega-3 fatty acids, like canola oil, are especially fragile. So fragile, in fact, that temperatures above 120 F. trigger rancidity. Please avoid rancid fats. They speed aging, suppress the immune system, are carcinogenic and challenge the digestive and cardiovascular systems.

Unfortunately, the majority of oils in natural food stores and supermarkets, even some organic, expeller pressed oils, are rancid because of poor processing and storage conditions. Most are bleached, de-flavored and deodorized at temperatures above 500 degrees F. When rancid oil is stripped of flavor and aroma we can no longer taste its rancidity, but rancid it is.

Fortunately, it doesn't take a Ph.D. in chemistry to discern good oils from bad. There are two tests. First, purchase quality fats that smell and taste like the foods from which they were made. Thus, quality canola oil smells and tastes like the hybrid rape seed from which it was pressed. That over 98 percent of all canola oil sold has no aroma or flavor aptly categorizes it as a highly refined, and therefore a rancid oil. I don't recommend highly refined oil for any culinary use.

A second quality indicator is how oil feels in your mouth. Within seconds of swallowing a sip of vital oil your mouth feels fresh and clean. It's as if your body, knowing that good oil is indispensable, invites it right in. On the other hand, a refined or denatured oil tastes greasy and coats (rather than dissolves in) the mouth. Imagine how this greasy stuff gums up arteries and insults the liver.

To protect quality oils from light, purchase and store them in opaque containers such as tin cans or black or amber bottles.

To protect oils from heat, keep them refrigerated (olive oil and ghee excepted). Additionally, learn which fats take high cooking temperatures. The solid, saturated fats, like butter and coconut oil, tolerate high heat (above 240 degrees) and you may bake with them. Unsaturated, omega-6 fatty acid oils like sesame and safflower withstand moderate heat, up to 240 degrees and are good for frying at moderate temperatures. When grilling, I favor a dry marinade or rub, a mixture of herbs and spices, over an oil-based marinade.

So what about cooking with oils containing omega-3 fatty acids, like canola, flax and hemp oil? If they underwent high temperatures during manufacture they're rancid and so please don't use them. If they were processed at low temperatures, properly packaged and they taste fresh and vital then still don't cook with them. However, enjoy these tasty oils as a supplement or in salad dressings. An excellent source is at www.omegaflow.com.

I hope this information helps you. Thanks for visiting and may you be well nourished.