Time For An Oil Change?

With so many cooking and salad oils on store shelves these days, which should you choose?

By Carol Sorgen
WebMD Weight Loss Clinic - Feature

A stroll down the cooking oil aisle of your local supermarket may leave you shaking your head. So many choices? olive, corn, canola, safflower. The list seems to go on and on. Which do you choose?

Before answering that question, it helps to know a bit about cooking oils in the first place.

Fats and oils are made up of "building blocks" called fatty acids. Each type of fat or oil is a mixture of different fatty acids:

  • Saturated fatty acids are found primarily in animal sources such as meat and poultry, whole or reduced-fat milk, and butter. Some vegetable oils like coconut, palm kernel oil, and palm oil have saturated fats. Saturated fats are usually solid at room temperature.
  • Monounsaturated fatty acids are usually found in vegetable oils such as canola, olive, and peanut oils. They are liquid at room temperature.
  • Polyunsaturated fatty acids are found mainly in vegetable oils such as safflower, sunflower, corn, flaxseed, and canola oils. Polyunsaturated fats are also the main fats in seafood. They are liquid or soft solids at room temperature. Specific polyunsaturated fatty acids, such as linoleic acid and alpha-linolenic acid, are called essential fatty acids. They are necessary for cell structure and making hormones. The body does not manufacture its own essential fatty acids; they must be obtained from the foods we eat.
  • Trans fatty acids are formed when vegetable oils are processed into margarine or shortening. Sources of trans fats in the diet include snack foods and baked goods made with partially hydrogenated vegetable oil or vegetable shortening. Trans fatty acids also occur naturally in some animal products such as dairy products.