I know most oils get damaged when cooking them over heat. What are some of the best oils to cook with?

Olive oil will be your best bet, its resistant to denaturation from heat and laboratory tests show Olive oil to be a mitochondria uncoupler which will improve fatty acid oxidation...plus it tastes pretty darn good.

Am I mistaken, or doesn't any oil become mildly (1/100) toxic when fried? -Tim

From what i've read on the subject, olive oil and some of your other polyunsaturated oils hold up relatively well to heat, i believe it is in the 400 degree range.

So most of your polyunsaturated oils cook pretty well. Thanks for the tips everyone.

From udoerasmus.com:

How can typical processing methods alter fats and endanger health?

Foremost among destructive processing methods are hydrogenation (or hardening), frying, and the processes used to make cooking (refined, bleached, deodorized [RBD]) oils.


Hydrogenation, which is used to turn oils into margarine, shortening, or partially hydrogenated vegetable oil, produces trans- fatty acids, which are twisted molecules. Twisted, their shape changes, and they lose their health benefits and acquire toxicity instead.


According to the Harvard School of Public Health, trans- fatty acids double risk of heath attack, kill at least 30,000 Americans every year, and increase diabetes. Other research shows that they interfere with vision in children, interfere with cerebral cortex function (lower intelligence), interfere with liver detoxification, make platelets more sticky, correlate with increased prostate and breast cancers, interfere with insulin function, and in animals (no human studies done) interfere with reproduction. They also interfere with EFA functions, and make EFA deficiency worse.


Frying has been known for 40 years to increase cancer and heart disease. During frying, oils are exposed to the destructive effects of light, air, and heat, all at the same time.


Cooking is best done with water (steam, poach, boil, pressure cook). Hard (saturated) fats (ghee, lard, coconut, palm) are damaged less when used in frying than are the liquid oils.





The richer an oil is in EFAs (especially n-3), the more it is damaged when fried, and the more toxic it becomes.


When fried food turns brown, the brown part is toxic. That's because when it is fried, the food loses water and dries out, then overheats and burns. If the food remains wet, it cannot burn. Only the outside of fried food burns: the inside is steamed, even in a frying pan.


The same premise applies to baking. The outside (crust) dries out, overheats, and burns. The inside of the bread remains moist, and is steamed.


To prevent overheating and burning, use water in a pot or pan, and use a lid so the food remains wet. Then it cannot burn. Take care that when you protect the top of the food from burning, you don't forget the bottom of the food. Stir or add water to keep the bottom of the food from burning.


Cooking oils are made by treating oils pressed from seeds with corrosive base, corrosive acid, and bleaching clays. This is done to remove 'minor' ingredients, which have major health benefits, but shorten the shelf stability of the oil.


Bleaching turns oils rancid, and they acquire a bad odor of rancidity. They must then be deodorized to remove the rancid odor, and this process is carried out at frying temperature.


Oils treated this way have lost most of their minor ingredients, are unbalanced, and contain about 0.5 to 1% molecules that have been changed by the processing from natural to toxic.


All of the cooking oils normally found on store shelves have been treated this way (these are the refined, bleached, deodorized or RBD oils), except for extra virgin olive oil, which has not undergone RBD processing and retains its minor ingredients intact.


Extra virgin olive oil should not be used for frying. Italians traditionally used butter and lard for frying, fried seldom, and added extra virgin olive oil to foods after these have been cooked with water.


Saturated (hard) fats like butter, dairy fats, pork, beef, and lamb fats, and tropical fats are natural. All foods contain some. The body uses them for energy and in cells and tissues. These fats cause problems only if we do not get enough EFAs in our diet.


EFAs and saturated fats have opposite effects in the body. EFAs (especially n-3) increase insulin sensitivity and make platelets less sticky, making a clot in an artery (stroke, heart attack, embolism) less likely. Saturated fats, on the other hand, increase insulin resistance and make platelets more sticky.


To prevent the negative effects of saturated fats, we need to make sure that we optimize our intake of EFAs before we start using saturated fats in our diet. And we need to make sure that EFAs always win the competition with saturated fats.

That's an interesting read, although i wonder how unbiased the info is considering what the author of that article sells.

I also question the n-3 breakdown in cooking, here are two studies off of pubmed that would contradict that idea and give some evidence of improvement of the n-6/n-3 ratio in a food cooked in olive oil.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12840197&dopt=Abstract

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12090031&dopt=Abstract

...I also found it interesting that EPA was enhanced yet DHA denatured, i'm not quite sure why that would be the case, perhaps some one more knowledgeable in biochemistry could explain that one to me.