A large number of comparisons were available for antioxidant
activity in organic and conventional crops (160 for the
unweighted meta-analysis and sixty-six for the weighted
meta-analysis), but the authors used a wide range of different
methodologies. Both weighted and unweighted meta-analyses
detected a significantly higher antioxidant activity in organic
crops (Fig. 3) and the MPD was 17 (95 % CI 3, 32) % (Fig. 3).