"Recent research has provided incontrovertible evidence that a Mediterranean-style diet rich in olive oil is not only generally healthy but consuming olive oil can actually reduce cholesterol levels.
Besides being a monounsaturated fat, virgin olive oil, because it is a completely natural untreated food, rich in anti-oxidants and vitamins, which help prevent body cell ageing, as well as giving the oil itself conservation properties. Since olive oil also contains Vitamin E and oleic acid, it aids normal bone growth and is particularly suitable for expectant and nursing mothers because it encourages the development of the infant's brain and nervous system before and after birth. From all this evidence doctors and nutritionists recognize extra virgin olive oil as having the most balanced composition of fatty acids (saturated, monounsaturated and polyunsaturated) of all edible vegetable oils." ³
"Willet and Sacks, two Harvard researchers, published a paper in The New England Journal of Medicine in favour of the traditional Mediterranean Diet in which 35-40% of calorie intake is in the form of fat, above all olive oil. The paper explains that one of the most striking features of the Mediterranean Diet is its effect on HDL or "good" cholesterol, which does really seem to protect against cardiovascular diseases. An olive-oil-rich diet appears to keep the arteries free of "bad" cholesterol while maintaining HDL cholesterol at healthy levels." ³
³ International Olive Oil Council
Technically
"The bulk of olive oil (98.5% - 99.5%) is made up of what is known as the saponifiable fraction. This consists of triglycerides - esters of glycerol with fatty acids - and free fatty acids. They can be joined by single bonds - in which case they are called saturated fatty acids - or by single bonds and one double bond - these are monounsaturated fatty acids - or by several double bonds, which case they are known as polyunsaturated fatty acids.
The behaviour and characteristics of vegetable oils depend to a large extent on the proportions of fatty acids they contain.
There is a predominance of fatty acids with 18 carbon atoms. Olive oil contains a preponderance of oleic acid, which is a mono-unsaturate. Fatty acid proportions vary in olive oil depending on region, olive variety, year, etc.
The other fraction in olive oil is known as the unsaponifiable fraction. It accounts for a very small part, but is of great significance as regards its biological value. The chlorophyll content, which gives a green color, and the carotene content, which is a reddish pigment, lend each oil its final color.
The volatile aromatic components influence odor and flavor. Poly- phenols account in part for flavor but due to their antioxidant nature they have a decisive effect on the stability of the oil, in other words on its keeping properties and resistance to degenerative phenomena. Tocopherols are also present, predominantly vitamin E (alpha-tocopherol) which also has antioxidant properties. Sitosterol is the major sterol found. Olive oil contains no cholesterol." ²
² an exert from The Olive Tree, The Oil, The Olive