Author: Winston Craig, MPH, PhD, RD.
No tree is more closely associated with the history and development of human civilization than the olive. The olive tree is a traditional symbol of peace, prosperity, and performance. Leafy wreaths were used to crown the winner in athletic games, and the victorious after war.
Throughout the Mediterranean region, the fruit, oil and leaves of the olive tree (Olea europaea) have made a significant contribution to the health and well-being of the local inhabitants. While olive oil is well known for its health benefits, the medicinal value of the leaf is less well known.
What Actually Are Olive Leaves?
Olive leaves, considered to be an agricultural waste, refers to a mixture of leaves and branches from pruning olive trees as well as from the harvesting and cleaning of olives.About 5 percent of the weight of harvested olives collected at the oil mill end up designated as olive leaves. Olive leaf tea is a common, traditional herbal tea used throughout the Mediterranean region to cure a variety of diseases. Olive leaf extracts are also combined with olive oil for soaps and skin creams.
A Real Fighter
Olive leaf extract is commonly used as an antibiotic to fight colds and flu, yeast infections, and viral infections such as the Epstein-Barr virus, and to treat gout. Various studies have reported the antioxidant, antibacterial, antifungal, and anti-inflammatory effects of olive leaves.
Olive leaves are widely recognized in Europe as a traditional herbal remedy to treat diabetes and hypertension. Animal studies have confirmed the reports that olive leaves have beneficial effects on diabetes, in addition to their ability to lower blood pressure, blood glucose, and cholesterol levels, and increase blood flow by relaxing the arteries. Preliminary research has shown olive leaf extract is effective for the treatment of liver, prostate, and breast cancer. The extracts limit the growth of leukemic cells and induce apoptosis (death of cancer cells).
The Potency of Oleuropein
The active compounds in olive leaves include oleuropein, flavonoids (such as hydroxytyrosol), triterpenes, and various polyphenolics. Oleuropein is a potent antioxidant endowed with significant anti-inflammatory properties. The oleuropein content of olive leaves is 10-200 times greater than that of olive oil. Oleuropein can prevent cardiac disease by promoting coronary blood vessel dilation, exerting anti-arrhythmic action, and improving lipid metabolism. Oleuropein in olive leaves has also been found to accelerate the uptake of glucose by the cell.
Hydroxytyrosol, a metabolite of oleuropein, has an action similar to oleuropein, and protects against atherosclerosis. The flavonoids in the olive leaves exhibit synergism, thus enhancing their natural biological properties. The triterpenes in olive leaves exhibit a potent antioxidative activity as well as lowering blood glucose and blood lipid levels in lab animals possessing abnormal biochemical parameters.
How Is It Consumed?
Olive leaf can be taken as a liquid concentrate, dried leaf tea, powder, or capsule. The freshly-picked olive leaf liquid extracts are gaining popularity due to the broader range of healing compounds they contain. The effective dose of olive leaves is yet to be determined for humans.