The fat content is the same for all oils, therefore, as far as the caloric content is concerned, all oils provide the same quantity of energy, that is to say, in one sense, they are equally fattening. However, from a nutrition point of view, olive oils can be preferred, because of the optimal acid composition and the presence of antioxidizing components and vitamins. It is widely believed that antioxidant substances such as vitamins E, K and polyphenols found in olive oil provide a defense mechanism that delays ageing and prevents cancer, atherosclerosis, liver disorders and inflammations. Every fat has a particular tolerance for high temperatures known as its smoke point. Beyond that level fats decompose, forming toxic compounds. Olive oil, besides having an high smoke point , contains many antioxidizing substances (polyphenols, tocopherols,etc.) that protect its composition, especially in subsequent cooking with the same oil. Because of its low acidity and antioxidant content, one can say that it is the most suitable oil for frying. When heated, olive oil is the most stable fat, which means it stands up well to high frying temperatures. Its high smoking point (210 degree C) is well above the ideal temperature for frying food (180 degree C). The digestibility of olive oil is not affected when it is heated, even when it is re-used several times for frying.