Tea tree oil does not cause anti-biotic resistance in humans, according to an “international” study led by researchers from the University of Western Australia (UWA). The study found no evidence to support recent reports that exposing bacteria to the oil contribute to anti-biotic resistance in humans.

The tea tree oil is popularly used in cosmetic products. Its antiseptic properties helps fight off skin blemishes, like acne. It also suggested that it is medically beneficial when appliad topically,such as anti-viral properties, among others. However, it is toxic when swallowed and should be kept away from children and pets.

Researchers at UWA have been studying the antimicrobial properties of tea tree oil since the early 1990s and its anti-cancer effects since 2007.

To test out their hypothesis, UWA’s Dr Christine Carson and her colleagues from UWA, PathWest and a university in The Netherlands exposed golden staph (Staphylococcus aureus) and other bacteria to tea tree oil. Their research found no difference in resistance to antibiotics compared to bacteria not exposed.

“The need for new antimicrobial agents is particularly pressing owing to the continued occurrence and spread of resistance to existing agents,” the authors wroe.

“Agents from different chemical classes that have diverse mechanisms of action would be most welcome. One possibility is tea tree oil.”

“It has broad-spectrum in vitro activity against bacteria, including antimicrobial-resistant and multiresistant organisms, and its use for the decolonisation of methicillin-resistant golden staph has attracted particular attention.”

According to the researchers, the weight of evidence now shows that tea tree oil does not contribute to antibiotic resistance.

“It is low-level exposure to tea tree oil that is alleged to promote resistance to it and other antimicrobial agents. But we found that tea tree oil does not in fact induce resistance,” said Dr. Carson.

Tea tree oil is a natural, renewable resource from Melaleuca alternifolia, a tree native to Southeast Queensland and northeast coast of New South Walesin Australia. Australia exports 90% of its tea tree oil to North America and Euope. It is also where most commercial production of the oil is done, with 3000 hectares dedicated to its cultivation and 100 producers.

According to the press release from UWA, tea tree oil was used--- the earliest on record---by the Bundjalung Indigenous people of northern NSW who treated their coughs, colds and wounds with crushed leavesof the tree.