Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses.

British Journal Of Nutrition (Impact Factor: 3.34). 06/2014; DOI: 10.1017/S0007114514001366
Source: PubMed

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.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Natural ecosystems persist without synthetic inputs. Would mimicking the organization of natural ecosystems enhance the productivity, year-to-year stability, or long-term sustainability of agriculture? Ecological research has disproved once widely accepted ideas, such as the assumption that homeostatic mechanisms in natural ecosystems are as reliable as those in organisms. Although there are still many unanswered questions, we argue that natural-ecosystem organization (diversity, spatial patterns, etc.) is not necessarily superior to that in well-designed agricultural ecosystems, especially by criteria relevant to agriculture. Furthermore, agriculture׳s constraints (exporting protein to cities, challenges in managing mixtures) would limit mimicry even of any hypothetical natural ecosystems with superior organization. Unlike overall ecosystem organization, individual adaptations of wild species have been consistently improved over millennia, via competitive natural selection. These adaptations, which might be applied to improve pest resistance or stress tolerance of crops, may best be studied in the natural ecosystems where they evolved.
    12/2014; 4. DOI:10.1016/j.gfs.2014.12.002

Full-text (4 Sources)

Available from
Jun 30, 2014