Olive oil is a vegetable oil. It is made by getting the juice of the fruits of the olive tree. These are called olives. The oil is used in cooking, as well as cosmetics, traditional medicine, and as a fuel for oil lamps. Refined olive oil uses heat and chemicals to get the fat out of the olives.[1]
Olive oil quality is defined by some parameters that are measured by chemical analysis. One of the most important is acidity. The highest quality olive oil (Extra-Virgin) must feature an acidity lower than 0.8%.[2]
People see it as a healthy addition to their diet because of the high level of monounsaturated fats (mainly oleic acid) and polyphenols.[3] Olive oil is popular in Mediterranean countries. It is a big part of the Mediterranean diet as a main fat source.[4]