Olive oil is rich in monounsaturated fatty acids (MUFA), which promote heart health by decreasing "bad" LDL cholesterol without reducing the "good" HDL cholesterol. The invisible healers within this "liquid gold" also work to prevent cancer, inflammation, and may even play a helpful role in diabetes and weight loss.
Research indicates that replacing other types of fats with monounsaturated fats, especially olive oil, helps people lose weight without additional food restriction or physical activity (although doing so would further increase weight-loss!). A number of studies showed that when people substituted MUFA-rich olive oil for saturated fat, they ate less food and either maintained their weight or lost weight. Several other studies indicate that monounsaturated fat enhances the body's breakdown of stored fat.
Olive oil is a good source of vitamin E, carotenoids, and polyphenolic compounds.
Selection and Storage
Extra virgin and virgin olive oils possess the monounsaturated fats (MUFA), nutrients, and phytochemicals that give health benefits your body will be happy to receive -- so choose them whenever possible.
Lite olive oils -- Also called "light" or "mild" -- have undergone an extremely fine filtration process (no heat or chemicals) to remove most of the natural color, aroma, and flavor. This makes them suitable for cooking or baking, where the fruity olive flavor would be objectionable. The terms "lite," "light," and "mild" can be used along with "extra virgin olive oil," "virgin olive oil," and "olive oil." In this case, the terms "lite" and "light" do not refer to fat content. These oils contain the same amount of fat and calories as any other oil (about 13 grams of fat and 120 calories per tablespoon).
To prevent the formation of cell-damaging free radicals, store olive oil in a cool, dark place; the refrigerator is ideal. The best storage containers for olive oil are either tinted glass (to keep out light) or a non-reactive metal such as stainless steel. Avoid most plastic. Oil can leach noxious substances, such as PVCs, out of the plastic and into the oil. Containers need to have a cap or lid for tight resealing to keep out unwanted air.