Scientists have pinned down the constituent of olive oil that gives greatest protection from heart attack and stroke. In a study of the major antioxidants in olive oil, Portuguese researchers showed that one, DHPEA-EDA, protects red blood cells from damage more than any other part of olive oil.

“These findings provide the scientific basis for the clear health benefits that have been seen in people who have olive oil in their diet,” says lead researcher Fatima Paiva-Martins, who works at the University of Porto.

Heart disease is caused partly by reactive oxygen, including free radicals, acting on LDL or “bad” cholesterol and resulting in hardening of the arteries. Red blood cells are particularly susceptible to oxidative damage because they are the body’s oxygen carriers.

In the study, published in Molecular Nutrition & Food Research, Paiva-Martins and colleagues compared the effects of four related polyphenolic compounds on red blood cells subjected to oxidative stress by a known free radical generating chemical.

DHPEA-EDA was found to be the most effective, and protected red blood cells even at low concentrations. The researchers say the study provides the first evidence that this compound is the major source of the health benefit associated with virgin olive oils, which contain increased levels of DHPEA-EDA compared to other oils. In virgin olive oils, DHPEA-EDA may make up as much as half the total antioxidant component of the oil.

Paiva-Martins says the findings could lead to the production of “functional” olive oils specifically designed to reduce the risk of heart disease. “Now we have identified the importance of these compounds, producers can start to care more about the polyphenolic composition of their oils,” she says.

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 such as Croatia, France, Greece, Italy, Slovenia, Portugal, Spain, Syria, Tunisia, and Turkey.

Over 750 million olive trees are cultivated worldwide, 95% of which are in the Mediterranean region. At more than one-third of the world’s production, Spain is the top producer of olive oil in the world.

Most of global production comes from Southern Europe, North Africa and the Near East.

World olive oil production in 2006-2007 was 2.767 million tonnes, of which Spain contributed 40% to 45%.

Of the European production, more than 90% comes from Croatia, Greece, Italy, Portugal and Spain.

Types of Olive Oil :

* Extra-virgin olive oil comes from virgin oil production only, contains no more than 0.8% acidity, and is judged to have a superior taste. Extra Virgin olive oil accounts for less than 10% of oil in many producing countries. It is used on salads, added at the table to soups and stews and for dipping.

* Virgin olive oil comes from virgin oil production only, has an acidity less than 2%, and is judged to have a good taste.
* Pure olive oil. Oils labeled as Pure olive oil or Olive oil are usually a blend of refined and virgin production oil.
* Olive oil is a blend of virgin and refined production oil, of no more than 1.5% acidity. It commonly lacks a strong flavor.

* Olive pomace oil is refined pomace olive oil often blended with some virgin oil. It is fit for consumption, but may not be described simply as olive oil. It has a more neutral flavor than pure or virgin olive oil, making it unfashionable among connoisseurs; however, it has the same fat composition as regular olive oil, rendering it the same health benefits. It also has a high smoke point, and thus is widely used in restauraunts as well as home cooking in some countries.

* Lampante oil is olive oil not suitable as food; lampante comes from olive oil’s long-standing use in oil-burning lamps. Lampante oil is mostly used in the industrial market.

* Refined olive oil is the olive oil obtained from virgin olive oils by refining methods that do not lead to alterations in the initial glyceridic structure. It has a free acidity, expressed as oleic acid, of not more than 0.3 grams per 100 grams (0.3%) and its other characteristics correspond to those fixed for this category in this standard. This is obtained by refining virgin olive oils with a high acidity level and/or organoleptic defects that are eliminated after refining. Over 50% of the oil produced in the Mediterranean area is of such poor quality that it must be refined to produce an edible product. Note that no solvents have been used to extract the oil, but it has been refined with the use of charcoal and other chemical and physical filters. An obsolete equivalent is “pure olive oil”.