Consumption of organic diets does not affect intake and absorption of zinc and copper in men – evidence from two cross-over trials

Abstract

Agricultural methods may affect the nutritional composition of plants and cause complex changes in the food matrix. Whether this affects the dietary absorption of minerals that are important for maintaining health thorough life remains unclear. We compared the effects of organic and conventional diets on intake and absorption of zinc and copper in men. Two double-blinded, cross-over, intervention trials (3 dietary periods of 12 days with 2-week-long wash-out) were performed in 2008 (n = 17) and 2009 (n = 16) in young men. The diets were based on 9 crops grown in rigidly controlled organic and conventional systems in 2 replications over 2 years. The primary outcomes were intake and absorption of zinc and copper. The absorption was determined by faecal excretion of stable enriched isotopes extrinsically added to the entire menu. Within each year, the intake and absorption of zinc (overall mean ± SD; 12.35 ± 0.47 mg per 10 MJ and 44.6% ± 12.1, respectively) and copper (overall mean ± SD; 2.12 ± 0.28 mg per 10 MJ and 41.2% ± 13.2, respectively) were not different between the organic and conventional diets. The growing season had no effect on zinc intake and absorption, but the copper intake was higher (P = 0.01) and absorption lower (P < 0.005) in 2008 compared with 2009 (overall mean absorption ± SD; 35.3% ± 13.5 in 2008 and 54.0% ± 10.7 in 2009). In conclusion, organic agriculture does not affect the intake and absorption of copper and zinc in men. Consequently, it does not seem to promote the health beneficial role of these minerals in vivo.

Some Differences in Nutritional Biomarkers are Detected Between Consumers and Nonconsumers of Organic Foods: Findings from the BioNutriNet Project

“…Regarding plasma copper concentrations, no difference was found when comparing the 2 groups of individuals. This is concordant with crossover intervention trials using a stable isotope that did not report differences in copper metabolism after consumption of an organic compared with a conventional diet (41). Evidence regarding differences in copper content between organic and nonorganic foods is scarce; however, copper-based sanitary preparations are classically used both in conventional and organic agricultural practices.…”

Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics

“…Some of these data have partially been presented earlier: Yield data have been published in the supporting material of [21] as averaged over two instead of three field plots and in [18] as averages over 3 years. DM (%), N (%), and S (%) have been presented in [18] as averages over 3 years…”

“…Further details regarding field trial characteristics such as soil type, soil fertility, crop rotation, sowing and harvest dates, fertilizer rates, pesticide applications, climate data, etc. can be found in [18] and in the supporting material of [21]. …”

Increase of 4-Hydroxybenzoic, a Bioactive Phenolic Compound, after an Organic Intervention Diet

“…No changes in the concentration of inorganic elements in plasma were observed after either intervention. According to other authors, organic agriculture does not affect dietary copper [45,46] or zinc absorption [45]. However, a cohort from the NutriNet-Santé study presented a higher level of magnesium after following an OD, whereas no differences were found in iron absorption [45].…”