The most extensive systematic review ever conducted of literature published over 50 years finds no evidence of superior nutritional content of organic produce. The London School of Hygiene and Tropical Medicine report found organically and conventionally produced foods to be comparable in their nutrient content. They say there is no evidence that organically produced foods are nutritionally superior to conventionally produced foodstuffs. The study was published in The American Journal of Clinical Nutrition.
Over 50,000 papers were searched, but only 55 were identified as being of satisfactory quality. Analysis was conducted comparing the content in organically and conventionally produced foods of the 13 most commonly reported nutrient categories. For 10 out of those 13 nutrient categories there were no significant differences between production methods and nutrient content.
Differences that were detected were most likely due to differences in fertilizer useand ripeness at harvest and it's unlikely consuming these nutrients at the levels reported in organic foods would provide any health benefit. The school's Alan Dangour says the review indicates there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority.