The product, often sold in liquid form, contains at least 12 of the antioxidant polyphenols found in olive leaf thanks to the proprietary processing method developed by privately owned family firm Olive Leaf Australia.
"We had read in some studies that olive leaf compound had good antioxidant activity and decided to investigate this," said Julian Archer, one of the directors of the firm.
"But when the first results came back the researchers thought they had made a mistake, and went back to do further tests."
The team, led by Dr Lesley Stevenson at the Natural Products Pharmacology Unit at Southern Cross University, found that the olive leaf extract had an ORAC value of 10,465 mmol TE/g compared to 5,937 mmol for a green tea extract made by an internationally recognized plant extract firm and sold on the Australian market.
The gap was even wider for grapeseed supplements and vitamin C. While olive oil has long been thought to offer health benefits, particularly for the heart, making supplements from the olive leaf is a relatively new concept.
There is however an increasing number of companies offering such a product, in response to a study in 1999 demonstrating greater antioxidant activity than vitamins C and E. But Archer believes that many of the firm's competitors cannot offer such powerful antioxidant activity.
"Most herbal extracts are made from the dried leaf," he told NutraIngredients.com.
"But if you dry the leaf this reduces a lot of the compounds and shipping has a further damaging effect.
We harvest at sunrise and within two hours are doing the processing."
Tests using HPLC technology have found that the company's EvirOlea brand product, extracted using a natural, water-based process, is rich in many of the olive leaf compounds initially present when the leaf is still on the tree.
Olive leaf extracts are often measured by their oleuropein content but Archer and his scientific colleagues think there is a synergy with the other polyphenols.
This potent antioxidant effect could offer major health benefits.
The company has commissioned a bioassay in the coming months to test the extract for its anti-inflammatory activity, as well as impact on cancer cells.
The lab tests will also check for anti-bacterial and anti-microbial activity.
At the same time, a human trial, to be carried out by the University of Queensland and the Wesley medical institute, will investigate the impact of the antioxidants on cholesterol reduction as well as their capacity to lower blood pressure by relaxing the arteries.
Yet it appears that many Australian consumers have already decided on the health benefits offered by this olive leaf extract.
Since launching in 2001, the product now makes A$1 million per month.
The firm is also present in Asia with an office in Korea and plans to expand into Malaysia, Singapore and Taiwan, and it is in discussions with European businesses looking to supply this market too.
"Most customers are buying it for cold and flu, and others are buying it for particular conditions like arthritis, even though we cannot make claims for these," explained Archer.
Retailing at around A$40 for 500ml, the product's safety is supported by its presence on the Australian register of therapeutic goods.
External links to companies or organisations mentioned in thisstory: Olive Leaf Australia