Olive oil is an oil obtained from the olive (Olea europaea; family Oleaceae), a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps. Olive oil is used throughout the world, but especially in the Mediterranean countries.
A widespread view exists that the first cultivation took place on the island of Crete. Archeological evidence suggest that olives were being grown in Crete as long ago as 2,500 B.C. The earliest surviving olive oil amphorae date to 3500 BC (Early Minoan times), though the production of olive is assumed to have started before 4000 BC. An alternative view retains that olives were turned into oil by 4500 BC by Canaanites in present-day Israel.
Ancient oil press
Bodrum Museum of Underwater Archaeology, Bodrum, Homer called it “liquid gold.” In ancient Greece, athletes ritually rubbed it all over their bodies. Olive oil has been more than mere food to the peoples of the Mediterranean: it has been medicinal, magical, an endless source of fascination and wonder and the fountain of great wealth and power. Indeed the importance of the olive industry in ancient economies cannot be overstated. The tree is extremely hardy and its useful lifespan can be measured in centuries. Its wide and deep root system ensures its survival without additional watering, even in the water-sparse Mediterranean. It thrives close to the sea, where other plants cannot tolerate the increased salt content of underground water. Other than pruning in late spring, it needs minimal cultivation and its fruit matures in the late autumn in the Northern Mediterranean) or through the winter (further south), when other staple food harvests are over and there is no other agricultural work to be done. Olive collecting and processing is relatively straightforward, and needs minimal, mechanical technology. Olive oil, being almost pure fat, is dense in calories yet healthy, without adverse health effects. Unlike cereals which can be destroyed by humidity and pests in storage, olive oil can be very easily stored and will not go rancid for at least a year (unless needlessly exposed to light or extremely hot weather), by which time a fresh harvest will be available. The combination of these factors helped ensure that the olive industry has become the region’s most dependable food and cash crop since prehistoric times.
Nutrition and health effects
Olive oil contains a wide variety of valuable antioxidants that are not found in other oils. Hydroxytyrosol is thought to be the main antioxidant compound in olives, and believed to play a significant role in the many health benefits attributed to olive oil. Epidemiological studies suggest that olive oil has a protective effect against certain malignant tumours in the breast, prostate, endometrium and digestive tract. Research has revealed that the type rather than the quantity of fat seems to have more implications for cancer incidence.
Evidence from epidemiological studies also suggests that a higher proportion of monounsaturated fats in the diet is linked with a reduction in the risk of coronary heart disease. This is significant because olive oil is considerably rich in monounsaturated fats, most notably oleic acid.
In the United States, producers of olive oil may place the following health claim on product labels:
Limited and not conclusive scientific evidence suggests that eating about 2 tbsp. (23 g) of olive oil daily may reduce the risk of coronary heart disease due to the monounsaturated fat in olive oil. To achieve this possible benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories you eat in a day.
This decision was announced November 1, 2004, by the Food and Drug Administration after application was made to the FDA by producers. Similar labels are permitted for foods rich in omega-3 fatty acids such as Almonds and hemp seed.
There is a large body of clinical data to show that consumption of olive oil can provide heart health benefits such as favourable effects on cholesterol regulation and LDL cholesterol oxidation, and that it exerts antiinflamatory, antithrombotic, antihypertensive as well as vasodilatory effects both in animals and in humans. Additionally, Olive oil protects against heart disease as it controls the “bad” levels of LDL cholesterol and raises levels of the “good” cholesterol, HDL.
As they are the least processed forms of olive oil, extra virgin or virgin olive oil have more monounsaturated fatty acids than other olive oil. These types also contain more polyphenols, which may have benefits for the heart.
Some clinical evidence suggests that it is olive oil’s phenolic content, rather than its fatty acid profile, that is responsible for at least some of its cardioprotective benefits. For example, a clinical trial published in 2005 compared the effects of different types of olive oil on arterial elasticity. Test subjects were given a serving of 60 g of white bread and 40 ml of olive oil each morning for two consecutive days. The study was conducted in two stages. During the first stage, the subjects received polyphenol-rich oil (extra virgin oil contains the highest amount of polyphenol antioxidants like oleuropein or tyrosol). During the second phase, they received oil with only one fifth the phenolic content. The elasticity of the arterial walls of each subject was measured using a pressure sleeve and a Doppler laser. It was discovered that after the subjects had consumed olive oil high in polyphenol antioxidants, they exhibited increased arterial elasticity, while after the consumption of olive oil containing fewer polyphenols, they displayed no significant change in arterial elasticity. It is theorized that, in the long term, increased elasticity of arterial walls reduces vascular stress and consequentially the risk of two common causes of death—heart attacks and stroke. This could, at least in part, explain the lower incidence of both diseases in regions where olive oil and olives are consumed on a daily basis.
In addition to the internal health benefits of olive oil, topical application is quite popular with fans of natural health remedies. Extra virgin olive oil is the preferred grade for moisturizing the skin, especially when used in the oil cleansing method (OCM). OCM is a method of cleansing and moisturizing the face with a mixture of extra virgin olive oil, castor oil (or another suitable carrier oil) and a select blend of essential oils. Olive oil has been known for generations not only for its healing qualities but also as a natural, deep penetration moisturizer, regenerating skin cells and softening the tissue. Olive oil is also used by some to reduce ear wax buildup.
Olive oil can be used as an effective shaving oil to shave facial and other body hair.
Studies on mice showed that application of olive oil immediately following exposure to UVB rays has a preventive effect on the formation of tumors and skin cancer.
It is also widely used in cosmetics, soaps and are immensely beneficial in adding smoothness and softness to dry scaly skins especially during winter seasons.
Source and References http://en.wikipedia.org/wiki/Olive_oil