A new international study has found that adopting a healthy Mediterranean diet significantly increased pesticide consumption, while switching to organic food resulted in a substantial decrease.
Using a unique new intervention study model, an international team of experts led by Professor Carlo Leifert (Southern Cross University, Australia; University of Oslo, Norway) and Professor Chris Seal (Newcastle University, United Kingdom) compared the effect of a healthy diet (Mediterranean type) with a usual western diet and they also compared the effect of conventionally produced foods with organic foods on the consumption of pesticides, a group of environmental pollutants with known negative health effects.
The study was carried out with graduate students during an agricultural field course in Crete, Greece and lasted for five weeks. The conventional group consumed the Mediterranean diet made up entirely of conventional foods, while the intervention group consumed the same diet made entirely of certified organic foods. Before and after the intervention period, all participants ate their self-chosen usual Western diets, which according to their food diaries were low in fruits, vegetables and wine and consisted entirely of conventional foods. .
See Diet and food type influence pesticide consumption graphic credit Carlo Leifert
The main findings of the study, published in The American Journal for Clinical Nutrition, were as follows:
- the switch from a “Western” diet to a Mediterranean diet with a high consumption of fruits and vegetables resulted in a total consumption of insecticides and organophosphates more than 3 times higher;
- conventional fruits, vegetables and whole grains are the most important dietary sources of synthetic chemical pesticides;
- organic food production methods have resulted in significantly lower levels of pesticide residues (including insecticides, fungicides and herbicides) in fruits, vegetables and grain products; and
- consuming a Mediterranean diet based on conventional foods results in a total intake of pesticides 10 times higher than a Mediterranean diet consisting entirely of organic foods.
Professor Chris Seal (PhD), University of Newcastle, said: “This study provides clear evidence that our diet and the way we produce food can affect the level of exposure to synthetic chemical pesticides and ultimately , our health.”
Professor Carlo Leifert (PhD), Director of the Center for Organics Research Foundation at Southern Cross University, said: “Many of the synthetic pesticides detected in food and urine samples in this study are disruptive chemicals. confirmed or suspected endocrine (EDC). Exposure to pesticides 10 times higher from conventional foods may therefore provide a mechanistic explanation for the lower incidence of overweight / obesity, metabolic syndrome and cancer associated with high levels of organic food consumption in epidemiological studies. / cohort.
Professor Per Ole Iversen (MD), University of Oslo, said: “Observational studies increasingly show that the health benefits of increasing the consumption of fruits, vegetables and whole grains are partially reduced by the higher exposure to pesticides associated with these foods. Our study shows that consuming organic foods allows consumers to switch to a healthier diet without increasing the consumption of pesticides.
Dr Leonidas Rempelos (PhD), project leader of the study in Crete, said: “One of the difficulties in assessing the public health impacts of dietary exposure to pesticides is that once pesticides are widely used in food production, everyone is exposed. This study demonstrated the potential to use organic food consumers as a “low pesticide exposure control group” to study the effect of currently used and newly released pesticides on public health. ”
The authors of this study welcome the continuing public and scientific debate on this important topic. The entire database generated and used for the analyzes will be available on request for the benefit of other experts and interested members of the public.
Organic food purchased in Crete for the study of the Mediterranean diet (credit Carlo Leifert).
The study was funded by the Sheepdrove Trust, Drove Farm, Sheepdrove, Lambourn, Hungerford, RG17 7UN, UK (charity number: 328369; www.charitychoice.co.uk/the-sheepdrove-trust-124094). The funder played no role in study design, implementation, data analysis and interpretation, and report writing.
Diet and Food Type Affect Urinary Pesticide Residue Excretion Profiles in Healthy Individuals: Results from a Randomized Controlled Dietary Intervention Trial
Authors: Leonidas Rempelos, Juan Wang, Marcin Barański, Anthony Watson, Nikolaos Volakakis, Hans-Wolfgang Hoppe, W Nikolaus Kühn-Velten, Catherine Hadall, Gultakin Hasanaliyeva, Eleni Chatzidimitriou, Amelia Magistrali, Hannah Davis, Vanessa Vigar, Dominika-Tobernick, Steven Rushton, Per Ole Iversen, Chris J Seal, Carlo Leifert
Published in The American Journal of Clinical Nutrition, 2021; nqab308