The European Food Safety Authority (EFSA) oversees the safety assessment of genetically engineered (GE) crops in the European Union and has developed a study design and statistical approach for assessing the compositional equivalency between a GE crop and the corresponding non-GE crop on the basis of the results from a small number of concurrently grown reference lines. Confidence limits around the differences in mean analyte composition between the GE variety and the reference lines are compared with equivalence limits on the basis of the variability of the reference lines. Here, we evaluated the performance and consistency of the equivalence conclusions using a non-GE variety that is, by definition, equivalent to the non-GE crop. Using this approach across the same analytes with the same non-GE variety, it was found that equivalence could not be concluded for 19.7, 22.9, 25.4, and 53.5% of the analytes in four separate studies. In addition, equivalency conclusions for the same analyte often differed from study to study. These results call into question the consistency and value of this approach in the risk assessment of GE crops.
Keywords: EFSA guidance; crop composition; equivalence; genetically engineered; genetically modified; statistics.