title: Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses.
abstract: Demand for organic foods is partially driven by consumers' perceptions that they are more nutritious. However, scientific opinion is divided on whether there are significant nutritional differences between organic and non-organic foods, and two recent reviews have concluded that there are no differences. In the present study, we carried out meta-analyses based on 343 peer-reviewed publications that indicate statistically significant and meaningful differences in composition between organic and non-organic crops/crop-based foods. Most importantly, the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods, with those of phenolic acids, flavanones, stilbenes, flavones, flavonols and anthocyanins being an estimated 19 (95 % CI 5, 33) %, 69 (95 % CI 13, 125) %, 28 (95 % CI 12, 44) %, 26 (95 % CI 3, 48) %, 50 (95 % CI 28, 72) % and 51 (95 % CI 17, 86) % higher, respectively. Many of these compounds have previously been linked to a reduced risk of chronic diseases, including CVD and neurodegenerative diseases and certain cancers, in dietary intervention and epidemiological studies. Additionally, the frequency of occurrence of pesticide residues was found to be four times higher in conventional crops, which also contained significantly higher concentrations of the toxic metal Cd. Significant differences were also detected for some other (e.g. minerals and vitamins) compounds. There is evidence that higher antioxidant concentrations and lower Cd concentrations are linked to specific agronomic practices (e.g. non-use of mineral N and P fertilisers, respectively) prescribed in organic farming systems. In conclusion, organic crops, on average, have higher concentrations of antioxidants, lower concentrations of Cd and a lower incidence of pesticide residues than the non-organic comparators across regions and production seasons.
authors: School of Agriculture, Food and Rural Development, Newcastle University,Nafferton Farm, Stocksfield,Northumberland,NE43 7XD,UK.
authors: Marcin
authors: M
authors: Barański
authors: School of Agriculture, Food and Rural Development, Newcastle University,Nafferton Farm, Stocksfield,Northumberland,NE43 7XD,UK.
authors: Dominika
authors: D
authors: Srednicka-Tober
authors: School of Agriculture, Food and Rural Development, Newcastle University,Nafferton Farm, Stocksfield,Northumberland,NE43 7XD,UK.
authors: Nikolaos
authors: N
authors: Volakakis
authors: Human Nutrition Research Centre, School of Agriculture, Food and Rural Development, Newcastle University,Agriculture Building, Kings Road,Newcastle upon TyneNE1 7RU,UK.
authors: Chris
authors: C
authors: Seal
authors: School of Biology, Newcastle University,Ridley Building,Newcastle upon TyneNE1 7RU,UK.
authors: Roy
authors: R
authors: Sanderson
authors: School of Agriculture, Food and Rural Development, Newcastle University,Nafferton Farm, Stocksfield,Northumberland,NE43 7XD,UK.
authors: Gavin B
authors: GB
authors: Stewart
authors: Center for Sustaining Agriculture and Natural Resources, Washington State University,Pullman,WA,USA.
authors: Charles
authors: C
authors: Benbrook
authors: Department of Agricultural Sciences,School of Agriculture and Veterinary Medicine, University of Bologna,Viale Fanin 42,40127Bologna,Italy.
authors: Bruno
authors: B
authors: Biavati
authors: Department of Pesticide Control and Phytopharmacy,Benaki Phytopathological Institute,GR 14561 Kifissia,Athens,Greece.
authors: Emilia
authors: E
authors: Markellou
authors: Department of Organic Farming and Food Technology,Technological Educational Institute of Ionian Islands,Iosif Momferatou & Ilia Miniati PC28100,Argostoli, Cephalonia,Greece.
authors: Charilaos
authors: C
authors: Giotis
authors: Faculty of Human Nutrition and Consumer Sciences, Warsaw University of Life Sciences,Nowoursynowska 159c,02-776Warsaw,Poland.
authors: Joanna
authors: J
authors: Gromadzka-Ostrowska
authors: Faculty of Human Nutrition and Consumer Sciences, Warsaw University of Life Sciences,Nowoursynowska 159c,02-776Warsaw,Poland.
authors: Ewa
authors: E
authors: Rembiałkowska
authors: Department of Animal Physiology,Faculty of Biology, University of Warsaw,Miecznikowa 1,02-096Warsaw,Poland.
authors: Krystyna
authors: K
authors: Skwarło-Sońta
authors: Biotechnology and Food Research, MTT Agrifood Research Finland,FI-31600Jokioinen,Finland.
authors: Raija
authors: R
authors: Tahvonen
authors: Department of Gene Bank,Crop Research Institute (CRI),Drnovská 507/73, 161 06 Praha 6 -Ruzyně,Czech Republic.
authors: Dagmar
authors: D
authors: Janovská
authors: Research Institute of Organic Agriculture (FiBL),Ackerstrasse 113,CH-5070Frick,Switzerland.
authors: Urs
authors: U
authors: Niggli
authors: INRA, UR407 Pathologie végétale,67 allée des chênes,F-84143Montfavet Cedex,France.
authors: Philippe
authors: P
authors: Nicot
authors: School of Agriculture, Food and Rural Development, Newcastle University,Nafferton Farm, Stocksfield,Northumberland,NE43 7XD,UK.
authors: Carlo
authors: C
authors: Leifert
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D002104:Cadmium / Q000032:analysis*; D018556:Crops, Agricultural / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis; D058870:Food, Organic / Q000032:analysis*; D006801:Humans; D062385:Hydroxybenzoates / Q000032:analysis; D009753:Nutritive Value; D058871:Organic Agriculture; D010573:Pesticide Residues / Q000032:analysis*; D059808:Polyphenols / Q000032:analysis
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D062385:Hydroxybenzoates; D010573:Pesticide Residues; D059808:Polyphenols; D002104:Cadmium; C017616:phenolic acid