An international study conducted in Crete, Greece has found that moving from a Western diet to a non-organic Mediterranean diet based on a high intake of fruit and vegetables can result in insecticide and organophosphate levels three-times the normal level.

Even more alarming was the finding that a Mediterranean diet made from conventionally farmed food results in a ten times higher pesticide intake than a Mediterranean diet made entirely from organic produce.

The international research team included Southern Cross University’s Professor Carlo Leifert, the foundation Director of SCU’s Centre for Organics Research. Co-authors came from a range of institutions and the study was published in The American Journal for Clinical Nutrition.

The study, Diet and food type affect urinary pesticide residue excretion profiles in healthy individuals: results of a randomized controlled dietary intervention trial, compared the effect of a healthy Mediterranean type diet with a habitual Western diet, as well as the effect of conventionally produced foods with organic food on intake of pesticides, a group of environmental pollutants with known negative health effects.

The study was carried out with higher degree students during an agricultural field course in Crete and lasted five weeks. The conventional group consumed the Mediterranean diet made entirely from non-organic foods, while the intervention group consumed the same diet made entirely from certified organic foods. 

Before and after the intervention period all participants consumed their self-selected habitual Western diets, which according to their food diaries were low in fruit, vegetables and wine consumption, and consisted entirely of conventional foods.
 
The study’s main findings were that:     

  • switching from a “Western” to a Mediterranean diet with high fruit and vegetable consumption resulted in more than 3-times higher total insecticide and organophosphate intake;
  • conventional fruit, vegetables and wholegrain cereals are the most significant dietary sources for synthetic chemical pesticides;
  • organic food production methods resulted in substantially lower pesticide (including insecticide, fungicide and herbicide) residue levels in fruit, vegetables and cereal products; and
  • consuming a Mediterranean diet made from conventional food results in 10 times higher total pesticide intake than a Mediterranean diet made entirely from organic food

Prof Per Ole Iversen (MD) from the University of Oslo, said, ‘There is growing evidence from observational studies that the health benefits of increasing fruit, vegetables and wholegrain consumption are partially diminished by the higher pesticide exposure associated with these foods. Our study demonstrates that consumption of organic foods allows consumers to change to a healthier diet, without an increased intake of pesticides.’

 

Watch a video, filmed in Crete, featuring short interviews with the study’s researchers and participants: 

 

View Diet and food type affect pesticide intake graphic (credit Carlo Leiferr) 

Funding

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 had no role in study design, implementation, analysis and interpretation of the data, and writing of the report.