ConsiderationsOil Overview
- The best cooking oil has a high smoke point, does not break down when heated, contains healthy ingredients, lacks unhealthy ingredients and has an appropriate flavor.
- All oils are fats (NOT all fats are oils).
- All fat has 9-calories per gram. This is true of all oils, too.
- There are three basic categories of fat (based on their fatty acid content) -- Monounsaturated, Polyunsaturated and Saturated.
Health Factors
- In general, healthy oils tend to break down into unhealthy chemicals when heated.
- Unless heated, the healthiest fat is Monounsaturated fat. It raises the good HDL cholesterol ratio.
- When heated, Monounsaturated fat tends to break down and become unhealthy.
- The unhealthiest fat is Saturated fat. It is associated with the bad, artery-clogging LDL cholesterol, but it is also the most stable when heated.
- Trans fatty acids are twice as unhealthy as saturated fats.
- Trans fatty acids are in hydrogenated and partially-hydrogenated oils. Avoid them.
- Linolenic (Omega-3) and Linoleic (Omega-6) are essential fatty acids. They are healthy (especially Omega-3), but they break down and become unhealthy when heated.
- Western countries typically consume too much Omega-6 and not enough Omega-3. They must be balanced.
Shelf Life
- Oils have a relatively short shelf life and become rancid rather quickly. Rancid fats have been associated with atherosclerosis, heart disease and cancer.
- Shelf life for cooking oils is about 3-months to 1-year. Exposure to oxygen, heat and light diminish an oil's shelf life.
- Refined oils stay fresh longer and can be heated to higher temperatures, but they contain more impurities than unrefined oils.
- Saturated fat has the longest shelf life, but it is the most unhealthy fat.
- Polyunsaturated fat readily combines with oxygen in the air to become rancid.
- Dark cooking oils have shorter shelf lives than light-colored or clear oils.
- Anti-oxidants extend an oil's shelf life.