Eating a mainly organic diet for just seven days can reduce pesticide exposure in adults by almost 90 per cent, researchers have found.
The RMIT University study is the first to compare the differences in pesticide residues in adults who consume organic and conventional food.
Published in the journal Environmental Research, the small-scale trial found that one week of eating mostly organic food reduced organophosphate pesticide levels in urine by 89 per cent.
"Conventional food production commonly uses organophosphate pesticides, which are neurotoxins that act on the nervous system of insects - and humans - by blocking an important enzyme," Dr Oates said.
"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 per cent organic food was 89 per cent lower than the levels after eating conventional food.
The research was conducted by Dr Oates as part of her PhD project supervised by Professor Marc Cohen from RMIT's School of Health Sciences.
It was supported in part by a donation to RMIT from Bharat Mitra, co-founder of Organic India Pty Ltd. A follow-up study has received funding from Australian Organics.