No doubt about it. Olive oil is one of the healthiest fats around.

But you'll kill the health benefits if you overheat it. It can become rancid and generate toxic chemicals. One solution: Instead of heating the oil in the pan, just spritz some on your veggies, meats, or taters before cooking them.

Tastes Bad, Too
It's fairly easy to overheat both olive oil and cold-pressed canola oil, because they have relatively low smoking points (the point at which they begin to burn). You'll know if you've overheated the oil, because it leads to that burned, charcoal flavor. Yuck.

Different Temps, Different Tastes
Semirefined sesame oil, peanut oil, grape-seed oil, and virgin olive oil may be your best choices for cooking, because they contain mainly unsaturated fat and have relatively high smoking points; all of the oils can be heated in excess of 400 degrees Fahrenheit. Extra-virgin olive oil starts to burn at about 320 degrees Fahrenheit. Unrefined canola and sunflower oils are even more delicate, burning at about 225 degrees Fahrenheit. (Read our ultimate guide on good and bad fats.)

Once an oil has been overheated, you end up canceling out the major benefits. But treat the oils right and they'll treat your body right, too.

What About Corn Oil?
Read this article to understand why most Americans eat too much
of it.

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This tip originally ran on 8/20/2007.