The healthiest oils are those that are high in monounsaturated and polyunsaturated fats, such as vegetable oil and olive oil. These types of fats can help lower your risk of heart disease when used instead of saturated and trans fats.
When it comes to cooking, however, not all oils are created equal. Some oils can handle the heat, and some can't.
An oil's smoke point is the temperature at which it will start to smoke and break down. When cooking oil starts to smoke, it can lose some of its nutritional value and can give food an unpleasant taste.
Oils with high smoke points are good for high-heat frying and stir-frying. These include:
Oils with moderately high smoke points are good for sauteing over medium-high heat. These include:
Oils with low smoke points, such as flaxseed, pumpkin seed and walnut, are best saved for use in salad dressings and dips. Some oils, including avocado, grapeseed, olive and sesame, are versatile enough to be used for frying or in salad dressings.