"Recent studies have raised concerns for the health effects of these chemicals even at relatively low levels.
"Pesticide exposure in Australian adults is mainly through their diets, but there are other sources of exposure, so we wanted to find out the difference going organic could make.
"Our results show that people who switch to eating mainly organic food for just one week can dramatically reduce their exposure to pesticides, demonstrating that an organic diet has a key role to play in a precautionary approach to reducing pesticide exposure.
"While the clinical relevance of reducing pesticide exposure requires further studies conducted on a larger scale, this study is an important first step in expanding our understanding about the impact of an organic diet."
In the study, 13 participants were randomly allocated to consume a diet of at least 80 per cent organic or conventional food for seven days and then switched to the alternate diet for a further week.
Urinary levels of six metabolites of organophosphate pesticides (known as dialkylphosphates or DAPs) were analysed on the eighth day of each phase. The mean level of total DAP metabolites after eating a diet of at least 80% organic food was 89 per cent lower than the levels after eating conventional food. .
The research - conducted by Dr Oates as part of her PhD project and supervised by Professor Marc Cohen from RMIT's School of Health Sciences - was supported in part by a donation to RMIT University from Bharat Mitra, co-founder of Organic India Pty Ltd. A follow-up study has received funding from Australian Organics.