No effect of the farming system (organic/conventional) on the bioavailability of apple (Malus domestica Bork., cultivar Golden Delicious) polyphenols in healthy men: a comparative study

Abstract

Background: The organic food sales have been increasing during the recent years. It has been hypothesised that organically grown fruits are healthier based on their higher content of phytochemicals. However, data on the bioavailability of phytochemicals from organically or conventionally produced plant foods are scarce.

Methods: Two human intervention studies were performed to compare the bioavailability of polyphenols in healthy men after ingestion of apples from different farming systems. The administered apples were grown organically and conventionally under defined conditions and characterised regarding their polyphenol content and antioxidant capacity. No significant differences in the polyphenol content and the antioxidant capacity from the organic and conventional farming system were observed.

Results: In the short-term intervention study, six men consumed either organically or conventionally produced apples in a randomized cross-over study. After intake of 1 kg apples, phloretin (C (max) 13 + or - 5 nmol/l, t (max) 1.7 + or - 1.2 h) and coumaric acid (C (max )35 + or - 12 nmol/l, t (max) 3.0 + or - 0.8 h) plasma concentrations increased significantly (P < 0.0001) in both intervention groups, without differences between the two farming systems. In the long-term intervention study, 43 healthy volunteers consumed organically or conventionally produced apples (500 g/day; 4 weeks) or no apples in a double-blind, randomized intervention study. In this study, 24 h after the last dosing regime, the apple intake did not result in increasing polyphenol concentrations in plasma and urine compared to the control group suggesting no accumulation of apple polyphenols or degradation products in humans.

Conclusion: Our study suggests that the two farming systems (organic/conventional) do not result in differences in the bioavailability of apple polyphenols.