On the Use of Olive Oil

Olive (Olea europaea) is a small tree native to the Mediterranean, southern Asia, the Middle East, China and the Canary Islands. The species has been cultivated widely because of its many benefits and is considered naturalized in all the countries of the Mediterranean coast, as well as in Argentina, Saudi Arabia, Java, Norfolk Island, California and Bermuda.

Olive oil is one of the core ingredients in Mediterranean cuisine.  The word “oil” in multiple languages derives from the name of this tree and its fruit.  Fossil evidence indicates the olive tree had its origins some 20–40 million years ago in the Mediterranean and was cultivated for its fruit 7,000 years ago in Mediterranean regions.  Its origin can be traced to written tablets, olive pits, and wood fragments found in ancient tombs in the Levant and cookbooks referring to its use in Lebanon, Syria, Palestine, and Crete.

Fossil olive pollen has been found in Macedonia and other places around the Mediterranean. Fossilized olive leaves were found on the volcanic Greek island of Santorini (Thera) and were dated about 37,000 BCE. Imprints of the larvae of olive whitefly were found on the leaves. The same insect is commonly found today on olive leaves, showing that the plant-animal co-evolutionary relations have not changed since that time.  As far back as 3000 BCE olives were grown commercially in Crete.

Spanish colonists brought the olive to the New World, where its cultivation prospered in Peru and Chile. Cultivation quickly spread along the Pacific coast where the climate was similar to the Mediterranean.  Spanish missionaries cultivated olives at Mission San Diego de Alcalá in 1769 and orchards were started at other missions throughout California.  Olive oil production became a highly successful commercial venture from the 1860’s onward.  In Japan, the first successful planting of olive trees happened in 1908 on Shodo Island, which became the cradle of olive cultivation in Asia. 

Olives are one of the most extensively cultivated fruit crops in the world.  In 2011, about 9.6 million hectares were planted with olive trees, which is more than twice the amount of land devoted to apples, bananas, or mangoes. Only coconut trees and oil palms command more space. There are estimated to be 865 million olive trees are in the world today, 95% of which are found in Mediterranean countries where the olive has long been considered sacred.   

Olive branches symbolizing abundance and peace were ritually offered to deities and powerful figures in ancient Rome and Greece and used as emblems of benediction and purification.  They were used to crown the victors of friendly games and to signify the end of a war.  The use of olive oil in many religious ceremonies can be traced to the history of its use in ancient times to symbolize wisdom, fertility, power, and purity.

Olive was one of the main elements in ancient Israelite cuisine and used for lighting, sacrificial offerings, ointment, and anointment for priestly or royal office.  The olive tree is one of the first plants mentioned in the Hebrew Bible and one of the most significant. An olive branch was brought back to Noah by a dove to demonstrate that the flood was over (Book of Genesis, 8:11). 

The olive is listed in Deuteronomy 8:8 as one of the seven species that are noteworthy products of the Land of Israel.  The ancient Greeks smeared olive oil on their bodies and hair as a matter of grooming and good health.  Olive oil was used to anoint athletes in ancient Greece and burnt in the sacred lamps of temples.  The “eternal flame” of the original Olympic games was fueled by olive oil and victors of the olympic games were crowned with olive leaves.

In Homer's Odyssey, Odysseus crawls beneath two shoots of olive that grow from a single stock.  Greek myth attributed the understanding of olive husbandry to the ancient Greek hero Aristaeus, who also pioneered cheese-making and bee-keeping. Olive wood was used to fashion the most primitive Greek cult figures that were preserved for centuries and the Greeks claim the olive originated first in Athens, but this cannot be proven.

According to the fourth-century BC father of botany, Theophrastus, olive trees ordinarily attain an age of 200 years, but some trees growing on the Acropolis in his life time were believed to date back to the Bronze Age.  In On the Causes of Plants, Theophrastus makes clear that the olive is propagated by pits that are spread far and wide by birds, but a bearing olive tree can be grafted onto a wild olive to increase productivity.  In addition to being propagated by seed and grafting onto an existing tree, olives can be propagated from a piece of the trunk, the root, a twig, or a stake.

According to Pliny the Elder, a vine, a fig tree, and an olive tree grew in the middle of the Roman Forum to provide shade. The Roman poet Horace wrote that he survived on simple diet of olives, endives and mallows supporting the idea of the olive being one of the most perfect foods preferred by the ancients.

The Mount of Olives east of Jerusalem is mentioned several times in the New Testament. St. Paul's Epistle to the Romans compares the scattering and gathering of Israel to the widespread propagation of the olive tree.  The olive tree itself, as well as olive oil and olives, play an important role in the Bible and are mentioned seven times in the Quran.  The Prophet Muhammad is reported to have said: "Take oil of olive and massage with it – it is a blessed tree" (Sunan al-Darimi, 69:103).

Olive oil contains 93.3 grams of fat, of which 13.33 grams are saturated and 66.6 grams are monounsaturated.  It contains no carbohydrate or protein.  The fact that olive oil is so rich in monounsaturated fat, is believed to be the reason that populations from that region enjoy longer life expectancy and lower risks of heart disease, high blood pressure and stroke, compared with North Americans and Northern Europeans.

The monounsaturated fatty acids found in olive oil are healthier alternative to fats and oils used in cooking in other regions.  Studies carried out in Barcelona, Spain found that people who regularly consume olive oil are less likely to develop cardiovascular diseases, including hypertension (high blood pressure), stroke, and hyperlipidemia (high blood cholesterol and triglyceride levels).

Olive oil intake also appears to help reduce inflammation, endothelial dysfunction (problems with the inner linings of blood vessels), thrombosis, and carbohydrate metabolism.  Scientists in France concluded that older people who regularly used olive oil for cooking and salad dressing or with bread had a 41-percent lower risk of stroke, compared with those who never consumed it.  People whose diets are high in monounsaturated fats have a lower risk of depression than those whose diets are rich in the trans fats typically used in fast foods and mass-produced items, such as pastries.

Scientists from Barcelona in Spain found a key mechanism by which virgin olive oil protects the body against breast cancer, in contrast to other vegetable oils.  In contrast corn oil, an oil rich in polyunsaturated fatty acids, increases the aggressiveness of cancerous tumors.

Oleocanthal, a compound found in extra-virgin olive oil was found beneficial in preventing Alzheimer’s by helping to shuttle the abnormal Alzheimer's disease protein, beta-amyloid, out of the brain.  Findings of initial research done on mice suggest that oleocanthal boosts the production of two proteins and key enzymes that help remove beta-amyloid from the brain.  Rates of Alzheimer's disease are lower in Mediterranean countries, where consumption of olive oil is higher than anywhere else in the world.

In a laboratory experiment at the University of Granada in Spain, researchers found that the components of extra virgin olive oil appear to protect against acute pancreatitis. Investigators from Tunisia and Saudi Arabia carried out a study demonstrating that extra virgin olive oil may protect the liver from cell damage associated with the chemical reaction between free radicals and other molecules in the body. 

A scientific study in the United Kingdom found that consuming 2-3 tablespoons of olive oil daily could fend off ulcerative colitis.  Participants with that daily intake of oleic acid had a 90-percent lower risk of developing ulcerative colitis compared to those with the lowest intake.

Consuming cured olives has the some of the same benefits as consuming the oil, but may have a higher amount of sodium depending on how they are processed, making them a potential cause of high blood pressure.  Olives are also very high in vitamin E and other powerful antioxidants. Studies show that they are good for the heart, and may protect against osteoporosis and cancer.