GMO Feeding Studies
by Layla Katiraee
January 14, 2016
Proper experimental design is the foundation of any scientific publication. However, a study is not so easy to plan, particularly when it includes methods that are expensive or that use tools that are hard to find. To make things more complicated, many studies are performed as part of a Master’s or Doctoral thesis, and the investigator gains skills and knowledge throughout the course of the experiment. By the time the study is done, the investigator sees parts she would have done differently.
Studies that involve animals are especially complex, since you cannot “redo” a failed experiment as easily as you can with in vitro or in silico assays. Criticisms by reviewers and editors can seldom be addressed during the peer review process: if an editor or reviewer identifies a flaw in an animal feeding study, it often cannot be redone due to resource constraints.
Poorly designed GMO feeding studies abound, quite possibly due to these difficulties in performing any animal feeding study. Such studies are often used by people who claim GMO are dangerous. It can be difficult to determine if a study has been properly designed and performed. We’ve put together a list to help you navigate through the messy world of GMO feeding studies.
*The nutritional content of feed given to both control and treatment animals must be analyzed to determine if there are any differences other than the GM trait. If the feeds aren’t as identical as possible, any difference observed between the treated animals and controls cannot be attributed exclusively to the GM trait.
*Many papers have shown that the environment has a strong impact on nutrient and mineral content in crops, so a failure to perform this analysis is a critical flaw in any GM feeding study. Anti-nutrient content, and toxin-producing fungi and bacteria must be analyzed as well.
*For example, the paper “The Comparative Effects of Genetically Modified Maize and Conventional Maize on Rats” observed differences in organ size and other parameters between the rats fed a diet with GMOs and controls, however, without analysis of the feed we don’t know if the differences are due to the GM trait. Maize has natural variation in sugar content, protein content and other nutrients which could have given rise to the observed differences, rather than the Bt-trait to which the authors attributed the observed differences.