Nutritional Value of Organic Compared to Conventional Fruits, Vegetables and Grains - The Organic Center has posted on its www site " ... A comprehensive review of 97 published studies comparing the nutritional quality of organic and conventional foods ..." which concludes that " ... organic plant-based foods (fruits, vegetables,
grains) contain higher levels of eight of 11 nutrients studied, including significantly greater concentrations of the health-promoting polyphenols and antioxidants ... [and that] that organically grown plant-based foods are 25% more nutrient dense, on average, and hence deliver more essential nutrients per serving or calorie consumed ..."
You can view the report in it's entirety here.
The March 18, 2008 Organic Center News Release is posted here.