The debate over the health benefits of organic food has resurfaced after a French scientist said organic foods contain higher levels of nutrients than conventional food.
Denis Lairon of the University of Aix Marseille said a review of data compiled for the French food agency AFSSA indicated that organic plant products contain more dry matter and minerals, including iron and magnesium, and more antioxidant polyphenols such as phenols and salicylic acid.
Other findings included that 94-100% of organic food does not contain any pesticide residues, while organic vegetables contain far lower nitrate levels — about 50% less — than conventionally produced foods.
"This critical literature review indicates that organic agriculture, as developed until now, has the potential to produce high quality products with some relevant improvements in terms of contents of antioxidant phytomicronutrients, nitrate accumulation in vegetables and toxic phytochemical residue levels," wrote Lairon in his paper, which was published in the journal Agronomy for Sustainable Development.
His conclusions contrast markedly with those of a study commissioned by the UK's Food Standards Agency. In July, the FSA said an independent review of scientific evidence showed there were "no important differences in the nutrition content, or any additional health benefits, of organic food when compared with conventionally produced food."
Alan Dangour, the principal author of the FSA paper, said: "A small number of differences in nutrient content were found to exist between organically and conventionally produced crops and livestock, but these are unlikely to be of any public health relevance. Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority."
But the study was widely criticised. Charles Benbrook, chief scientist at the American pro-organic organisation, The Organic Center, said: "The London team downplayed positive findings in favour of organic food. In several instances, their analysis showed that organic foods tend to be more nutrient-dense than conventional foods. Plus, their study omitted measures of some important nutrients, including total antioxidant capacity."
Lairon, D. "Nutritional quality an safety of organic food, a review." Agronomy for Sustainable Development (2009) DOI: 10.1051/agro/2009019