The use of whole food animal studies in the safety assessment of genetically modified crops: Limitations and recommendations

Abstract

There is disagreement internationally across major regulatory jurisdictions on the relevance and utility of whole food (WF) toxicity studies on GM crops, with no harmonization of data or regulatory requirements. The scientific value, and therefore animal ethics, of WF studies on GM crops is a matter addressable from the wealth of data available on commercialized GM crops and WF studies on irradiated foods. We reviewed available GM crop WF studies and considered the extent to which they add to the information from agronomic and compositional analyses. No WF toxicity study was identified that convincingly demonstrated toxicological concern or that called into question the adequacy, sufficiency, and reliability of safety assessments based on crop molecular characterization, transgene source, agronomic characteristics, and/or compositional analysis of the GM crop and its near-isogenic line. Predictions of safety based on crop genetics and compositional analyses have provided complete concordance with the results of well-conducted animal testing. However, this concordance is primarily due to the improbability of de novo generation of toxic substances in crop plants using genetic engineering practices and due to the weakness of WF toxicity studies in general. Thus, based on the comparative robustness and reliability of compositional and agronomic considerations and on the absence of any scientific basis for a significant potential for de novo generation of toxicologically significant compositional alterations as a sole result of transgene insertion, the conclusion of this review is that WF animal toxicity studies are unnecessary and scientifically unjustifiable.

Consumer acceptance of food crops developed by genome editing

“…These results sensationally emerged in mass media, with warnings that GM crops are unsafe for food consumption (Marshall 2007;Romeis, et al 2013). However, accumulating evidence from other animal feeding experiments suggest that current GM crops in the marketplace are predominantly safe (EFSA_GMO_Panel_Working_Group_on_Animal_Feeding_Trials 2008), although some criticisms about scientific justification and methodology consistency of animal toxicity studies performed so far were raised (Bartholomaeus, et al 2013;Zdziarski, et al 2014). In contrast, it should also be noted that some food products which are not genetically modified may affect human health.…”

A 90-day subchronic feeding study of genetically modified rice expressing Cry1Ab protein in Sprague–Dawley rats

“…Ultimately, the intention is to assess whether the foods and feeds derived from GM crops, prior to commercialization, are as safe and nutritious as those derived from conventional crops that have an established history of safe use. Quite a lot of systematic reviews have been published in peer-reviewed journals, based on rigorous methodology and long-term animal feeding data, which unambiguously show no biologically or toxicologically relevant effects of commercialized GM crops Snell et al 2012;Bartholomaeus et al 2013). The particularly interesting aspect of these international studies is not only the fact that they were conducted by independent institutes from so many different countries, but also the variety of animals tested such as rats, mice, chickens, sheep, pigs, cows, and salmon.…”

The precautionary principle: Making managerial decisions on GMOs is difficult

“…The debate also includes evaluation of uncertainty in risk assessment, the validity of animal models 54 , variability in data 19 and lack of sufficient knowledge 47 . Approaches to assessment of GMOs, for example the substantial equivalence, and concepts of familiarity and 'history of safe use' have been criticised as pseudoscience.…”