"And the dove came in to him in the evening, and lo, in her mouth was an olive leaf plucked off. So Noah knew that the waters were abated from off the earth."
(Genesis 8 : 11)
After the Great Flood we didn't hear too much about the olive leaf for a long time. Obviously this was a hard act to follow.
In a much later biblical time (Ezekiel 47 : 12), God speaks of a tree: "The fruit thereof shall be for meat, and the leaf thereof for medicine."
Was it the olive tree?
In Revelations, at the very end of the New Testament, there is an angelic vision of a "tree of life" whose leaves "were for the healing of the nations." Today, as modern medicine increasingly embraces phytochemicals it is interesting to speculate about the biblical "tree of life."
Again, was it perhaps the olive tree?
The ancient Egyptians may be been the first to put the olive leaf to practical use. They regarded it as a symbol of heavenly power, and in keeping with that belief, they extracted its oil and used it to mummify their kings.
Later cultures found the leaf was better utilized for the living than the dead. Over the ages, there is documentation that it was a popular folk remedy for combating fevers.
The first formal medical mention of the olive leaf - an account describing its ability to cure severe cases of fever and malaria -- ocurred about 150 years ago. In 1854, the Pharmaceutical Journal carried a report by one Daniel Hanbury and contained the following simple healing recipe:
Boil a handful of leaves in a quart of water down to half its original volume. Then administer the liquid in the amount of a wineglass every 3 or 4 hours until the fever is cured.
The author said he discovered the effective tincture in 1843 and had used it successfully. This method became well known in England for treating sick Britons returning from His or Her Majesty's tropical colonies. The author believed that a bitter substance in the leaves was the key healing ingredient.
He was right.
Decades later, scientists isolated a bitter substance from the leaf and named it oleuropein. It was found to be one ingredient in a compound produced by the olive tree that makes it particularly robust and resistant against insect and bacterial damage. From a technical angle, oleuropein is an iridoid, a structural class of chemical compounds found in plants. It is present in olive oil, throughout the olive tree, and is, in fact, the bitter material that is eliminated from the olives when they are cured.
In 1962, an Italian researcher reported that oleuropein lowered blood pressure in animals. This triggered a flurry of scientific interest in the olive leaf.
Other European researchers confirmed this interesting finding. In addition, they found it could also increase blood flow in the coronary arteries, relieve arrhythmias, and prevent intestinal muscle spasms.
Around this time, a Dutch researcher determined the active ingredient in oleuropein to be a substance he called elenolic acid. It was found to have a powerful anti-bacterial effect.
By the late 1960's, research by scientists at Upjohn, a major American pharmaceutical company, showed that elenolic acid also inhibited the growth of viruses. In fact, it stopped every virus that it was tested against. Among others, the substance was found to counteract a variety of viruses associated with the common cold of humans.
Moreover, a number of laboratory experiments at this time with calcium elenolate, a salt of elenolic acid, demonstrated a strong effect against not just viruses, but bacteria and parasitic protozoans as well.
The compound worked effectively at low concentrations without any harmful influence on host cell mechanisms, the American researchers concluded. That meant they believed it to be extremely safe and non-toxic, even at high doses.
Following test tube experiments, the pharmaceutical company launched animal tests. Experiments showed the compound was indeed extremely well tolerated. There was a hitch, however. In the body of an animal, the substance rapidly attached to protein in blood serum. For all intents and purposes, this meant calcium elenolate was of no use. The binding action essentially took it "out of action," rendering it ineffective. As a result of this obstacle, research into the compound as a potential virus and bacteria killing pharmaceutical drug was dropped.
Nevertheless, research and interest in olive leaf extracts has moved forward, primarily in Europe. Among the most recent findings are these: