Scientific Findings About Organic Agriculture

About the Project

Organic agriculture developed from the philosophy of Rudolph Steiner and later Lady Eve Balfour, who in the 1940s founded the Soil Association in the United Kingdom. There are claims to the fact that the production and nutritive values of organic foods are superior to those of conventionally produced foods. This premise has however been avidly refuted by others, including University of Edinburgh professor Anthony Trewavas, with the claim that there is no “science” to substantiate such claims about organic foods.

This project was conducted to explore the scientific evidence about organic and conventional foods and offer the general opinion of scientists regarding organic foods and their impact on human health. This project is the result of a review of the scientific literature.

Research cited on this web site was selected if two conditions were met:

  1. The research was published in a scientific, peer-reviewed journal or publication, and
  2. The research involved a comparison or specific trait of organic food.

This web site contains summaries of the original articles, with appropriate references listed for a full review of articles. Descriptions about the scientific findings and conclusions are those of the original author, and not this project.

How is “organic food” defined?
There is no universal definition for organic food although the U.S. Department of Agriculture has outlined the guiding principles for organic agriculture.

In 1997, the USDA's National Organic Standards Board defined organic agriculture as

an ecological production management system that promotes and enhances biodiversity, biological cycles, and soil biological activity. It is based on minimal use of off-farm inputs and on management practices that restore, maintain, or enhance ecological harmony. The primary goal of organic agriculture is to optimize the health and productivity of interdependent communities of soil life, plants, animals and people.

Unlike food that is labeled “natural” or “eco-friendly,” the term “certified organic” is governed by uniform standards of production and processing that can be verified by independent state or private organizations accredited by the USDA.

In general, crop produce or products that qualify as organic must be

In addition to these requirements, organic animals also must be

What about newer studies of organic agriculture?
The original literature review was done in 2006 and 2007 by David Kwaw-Mensah, a doctoral student in the Department of Agricultural Education and Studies at Iowa State University. He worked under the direction of Jerry DeWitt, tenured professor in the ISU Department of Entomology and director of the Leopold Center for Sustainable Agriculture.

Photos used on the web site were taken by DeWitt. Design for these pages was developed by Charles Richards.

Summaries of new scientific research will be added to this web site on a periodic basis as they become available. Submissions of articles for review should be directed to the following:

Jerry DeWitt, Director, Leopold Center for Sustainable Agriculture
209 Curtiss Hall - ISU
Ames, IA  50011-1050

Or send an email to: organicag@iastate.edu

Be sure to include the complete reference citation and article to be reviewed.

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