Organic food: nutritious food or food for thought? A review of the evidence

Abstract

Apparently, one of the primary reasons for purchasing organic food is the perception that it is more nutritious than conventional food. Given the increasing interest towards organic food products, it is imperative to review the existing literature concerning the nutritional value of the produce, and to determine to what extent are consumer expectations met. There are only few well-controlled studies that are capable of making a valid comparison and, therefore, compilation of the results is difficult and generalisation of the conclusions should be made with caution. In spite of these limitations, however, some differences can be identified. Although there is little evidence that organic and conventional foods differ in respect to the concentrations of the various micronutrients (vitamins, minerals and trace elements), there seems to be a slight trend towards higher ascorbic acid content in organically grown leafy vegetables and potatoes. There is also a trend towards lower protein concentration but of higher quality in some organic vegetables and cereal crops. With respect to the rest of the nutrients and the other food groups, existing evidence is inadequate to allow for valid conclusions. Finally, animal feeding experiments indicate that animal health and reproductive performance are slightly improved when they are organically fed. A similar finding has not yet been identified in humans. Several important directions can be highlighted for future research; it seems, however, that despite any differences, a well-balanced diet can equally improve health regardless of its organic or conventional origin.

Effects of organic fertilizers on growth, yield, quality and sensory evaluation of red lettuce (Lactuca sativa L.) ‘Veneza Roxa’

“…These findings, however, are evident only for the plants that grow above the ground (leaf vegetables) such as spinach, lettuce, chard, savoy cabbage and white cabbage (Magkos et al, 2003). Therefore, our results concurred with results obtained by Magkos et al (2003).…”

“…A study by Magkos et al (2003) evaluated the dry matter content of several vegetables and found that organically cultivated crops had higher dry matter content than those grown conventionally. These findings, however, are evident only for the plants that grow above the ground (leaf vegetables) such as spinach, lettuce, chard, savoy cabbage and white cabbage (Magkos et al, 2003). Therefore, our results concurred with results obtained by Magkos et al (2003).…”

Production system and harvesting stage influence on nitrate content and quality of butterhead lettuce

“…Xu et al (2005) observed that vegetables grown with organic fertilizers performed better than those grown with chemical fertilizers. Magkos et al (2003) also confirmed that organic planting system produced higher biomass and better quality of different vegetables including lettuce than conventional planting system. In the present study, production system did not affect plant growth in terms of plant height and fresh weight of butterhead lettuce.…”

Segurança alimentar de hortaliças orgânicas: aspectos sanitários e nutricionais

“…Diversos autores relatam que os alimentos produzidos sob sistema orgânico possuem, frequentemente, teores de vitamina C superiores aos produzidos convencionalmente (CLARKE; MERROW, 1979;MULLER;HIPPE, 1987;LECLERK et al, 1991;BOURN;PRESCOTT, 2002;WILLIAMS, 2002;MAGKOS;ARVANITI;ZAMPELAS, 2003). Neste trabalho, foi possível observar que os teores de vitamina C das amostras de alface, tomate e cenoura orgânicas analisadas estavam acima dos valores registrados na TACO (UNICAMP, 2006), corroborando as literaturas citadas.…”