The olive plant is an evergreen that can grow to heights of 30 feet. It produces a fruit, the olive, and its oil is obtained from the fruit and leaves of the tree. Olive grows in the wild, in parts of the Mediterranean and is also cultivated in areas with similar climate. 
The traditional uses of olive by the inhabitants of the Mediterranean coast include; wound cleansing, cardiovascular problems, malaria, infection, and to support general well being. The olive leaf was used ornamentally as a status symbol, an emblem of peace, and was even included in various religious rituals.
The main constituents of olive are triterpenoid saponins. These include the compounds oleuropein, oleasterol, oleanolic acid, and ursalic acid. It also contains oleic acid, a mono-unsaturated fatty acid, and phenolic compounds which account for its antioxidant activity.
Today olive leaf is most commonly used as a remedy for high blood pressure. It has cardiotonic action via several different mechanisms. It is also considered an antimicrobial, anti-inflammatory, and hypoglycemic agent.
The leaf is the main part of the plant used for medicinal purposes, however the active constituents are contained in all parts of the plant, including its most active compound, oleuropein.
Olive Leaf Uses
As mentioned, olive leaf is primarily employed for the treatment of high blood pressure. It has been proven through various clinical applications to lower blood pressure, possibly by dilating the vessel walls. It is also thought to provide a relaxant effect on the heart, by acting as an antagonist to beta-adrenergic receptors.  This action is similar to beta-blockers.
- Olive leaf can also benefit individuals with arrhythmia. It can correct arrhythmia by causing sinus bradycardia, or a slow normal rhythm heart beat via beta-adrenergic receptors. 
- Olive leaf may also be helpful for atherosclerosis.  It is thought to inhibit the oxidation of LDL as a result of its antioxidant action.  Olive leaf has also been reported to decrease platelet aggregation, thereby decreasing clot formation and artery narrowing.
- Olive leaf has hypoglycemic properties and may be helpful for individuals with Type II diabetes mellitus as well. Olive leaf may cause more insulin to be released, as well as to increase the uptake of glucose out of the bloodstream.  It has also been shown to decrease insulin resistance in some individuals. 
- Olive leaf may be helpful for infections due to bacteria or viruses. It may also be helpful for Candida infections as well as fungal infections of the skin and nails, such as tinea corporis. 
- Olive leaf may be an emerging treatment for HIV. In vitro studies show that Olive leaf inhibits HIV reverse transcriptase.  It has also inhibited acute infection and cell-to-cell transmission, and has the potentiality to be used as a prophylactic in certain cases.  However, further clinical study is needed to confirm this possible treatment option.
Olive leaf can be taken in capsule or tea form. The most common dosage in capsule form is 250 - 500 milligrams (mg), one to four times a day. Many products are standardized to 10 - 15% oleuropein, the main acting constituent of olive leaf. A tea consisting of dried olive leaves can also be used medicinally: 2 teaspoons of leaves per cup of boiling water steeped for approximately 20 minutes. The tea can be drunk three to four times a day, or as needed.
There are no known side effects or toxicity associated with the use of Olive leaf. Olive leaf is contraindicated in people who have gallstones due to its ability to stimulate contraction of the gallbladder. 
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