University student scientist view of crop biotech safety critics: Where’s the beef?

As a graduate student at Cornell University in Plant Sciences whose research revolves around molecular biology I would like to present some background information on the science of crop genetics that some people may not be aware of.

Many of the allegations voiced by critics concern me because they have little or no scientific basis. For example, critics list a range of so-called health issues linked to eating genetically modified foods as if they are facts: “Independent studies show organ damage, accelerated aging, allergies, reproductive issues”; or “There is no reliable information about GM foods and their impact, especially regarding health effects”; or (vaguely and ominously) “GMO’s can be a threat to human and environment health”; or, reflecting one of the most common claims of the anti-biotech advocates: “Genetic engineering may cause unexpected allergic reactions”.

Based on papers published in prominent peer-reviewed science journals, these statements alleging that GM foods are unsafe are either untrue or dubious. I address each of these of these concerns below. (Readers can find more background by clicking the hyperlinks throughout this post.)

There is no documented proof that any approved, commercially grown GE crop has caused allergic reactions due to a transgenically introduced allergenic protein (Goodman et al. 2005; Goodman et al. 2008). Proteins of course can be toxic (for instance ricin, cholera toxin, botulinum toxin, diphtheria toxin). But to be toxic, they’d have to be able to survive digestion and get to their site of action. Let’s take Bt crops as one example. These crops produce a protein from the bacteria Bacillus thuringiensis that is toxic to certain types of insects (commonly called Bt toxin). This protein is activated at alkaline pH, while mammals have a basic pH in our digestive systems. Further, Bt proteins interact with specific receptors located on the surface of cells in susceptible insects, and other organisms do not have these receptors.

Note that we already have billions of bacterial cells in our gut containing proteins very similar to the EPSP synthase used in glyphosate-resistant varieties. Non-specific effects such as allergy can be an issue if the protein is resistant to degradation. However, if a prospective transgene passes toxicity testing including testing how well it is digested, there is no scientific basis to assume that it is more harmful than any other protein

There is also no evidence that the creation of a GE crop has caused a significant increase in the production of allergens (Goodman et al. 2005; Goodman et al. 2008). In fact, according to the Swiss National Research Programme NRP 59 (Sweet and Bartsch 2012), there are more than 1,000 scientific publications showing there is no evidence of harmful impacts on health from plant genetic engineering. You can read the entire report from Sweet and Bartsch or browse in the Swiss National Science Foundation website.

Crucially for science there is not only substantial research backing the safety of genetically engineered crops but there is also a consensus in the scientific literature (Kuntz and Ricroch 2012; Mendelsohn et al. 2003). I would encourage you to read the 30 scientific articles and reports addressing crop biotechnology safety cited at the bottom of this post. These are also many easily accessible papers using Google Scholar, a free web search that indexes the full texts of scholarly literature across an array of peer-reviewed journals. These studies and others are available for anyone to read critically, study and challenge. Some key excerpts from these studies focusing on crop biotechnology controversies:

  • [A] 90-day feeding study performed in rodents, according to the OECD Test Guideline, is generally considered sufficient in order to evaluate the health effects of GM feed. The studies reviewed present evidence to show that GM plants are nutritionally equivalent to their non-GM counterparts and can be safely used in food and feed (Snell et al. 2012).
  • “In this 90-day study, compared with the parental rice Minghui 63 and the control diet, the GM Bt rice T1C-1 exhibited no toxicological effects on SD rats when fed a 60% rice diet (Tang et al. 2012).
  • “The transgenic KMD1 rice expressing Cry1Ab protein was compared to its non-transgenic parental wild type, Xiushui 11. No adverse effects on animal behavior or weight gain were observed during the study (Schroder et al. 2007).”
  • “By using standard in vitro methods and SPT for determination of allergenicity we were not able to detect any significant difference in the allergenic potency between GM and WT soybeans (Sten et al. 2004). 

Each of these scientific findings on GMO safety are in accordance with the conclusions of every other respected science-based organization that has examined the evidence. In other words, the conclusions of independent scientists and scientists with industry links are identical—indicating that the industry research, often dismissed by critics as ‘tainted,’ is in fact state of the art and GMO foods are in fact safe. Key conclusions from select internationally respected science oversight groups:

  •  “[F]ood containing ingredients derived from GE crops (whether Bt or otherwise) is no riskier than the same food containing ingredients from crop plants modified by conventional plant improvement techniques,” according to the American Medical Association (AMA) 
  • “They [GE/GMO foods] are as safe as their non-GE counterparts,” according to the World Health Organization (WHO)
  • “No evidence has supported an increased degree of allergenicity of bioengineered foods compared to their non-bioengineered counterparts,” according to the U.S. National Academy of Sciences (NAS)

Others organization that have examined the safety of GMO products and have reached almost identical conclusions include:

Another key misconception promoted by critics is that research on genetic engineering has been solely ‘funded by industry’. That’s not accurate. First, it should be understand that most industry studies were required as part of the extended evaluation and approval process necessary for GE crops to be approved, so its understandable that a majority of studies in this field can be linked to industry. However well more than a third and as much as 40% of crop biotech studies have been carried out independently.

For example, most of the studies listed in this post were carried out by non-industry researchers at European universities backed by government financial support —the equivalent to getting support from the National Science Foundation in the United States. The financial support for three studies cited above (Schroder et al. 2007; Tang et al. 2012; Snell et al. 2012) came from the European Commission, the Shanghai Agricultural Science, China and the French Government, respectively. Sources of funding are, usually, stated in the papers. Some of the universities involved in carrying out the research presented in this post include:

  • Wageningen University, Toxicology section, Wageningen,The Netherlands
  • Braunschweig Univeristy of Technology, Federal Agricultural Research Centre, Institute of Animal Nutrition, Braunschweig, Germany
  • Wageningen University, GMO Panel member, RIKILT Institute of Food Safety, Wageningen, The Netherlands
  • Universite de Bretagne Occidentale, Plouzane, France
  • French National Institute for Agricultural Research, INRA, Paris, France
  • Wageningen University, RIKILT Institute of Food Safety, The Netherlands
  • University of Reading, School of Agriculture, Policy and Development, Berkshire, UK
  • GMO Panel member, Federal Institute for Risk Assessment, Berlin, Germany
  • University of Copenhagen, Danish Institute for Food and Veterinary Research, Copenhagen, Denmark
  • Centro de Investigacion y de Estudios Avanzados del IPN, Mexico
  • The University of Nottingham and The University of Aberdeen, UK
  • AgroParisTech, Laboratory Végétale Physiologie Cellulaire, CNRS-INRA, France
  • Univeristy of Copenhagen, Allergy Clinic, National University Hospital – Denmark
  • Shanghai Normal University, College of Life and Environment Sciences, People’s Republic of China
Related article:  Farmers worry over weed control in corn as EPA mulls future of atrazine

For more information on the controversy over the safety of genetically engineered foods, please review the large volume of research in the biotechnology area provided by the GMO-Safety team, which is part of the collaborative project on communications management in biological safety research commissioned by the German Federal Ministry of Education and Research and is totally independent., which is an independent website focusing on crop biotechnology and sustainability, is also a good place to get factual information on plant genetics and genetic engineering as the volunteer authors include graduate students, professors and guest experts. The site also hosts the GENERA database, which includes an expanding list of more than 600 crop biotechnology studies, and will soon be searchable.

Lastly “GMO compass Genetic engineering in the EU” financially supported by the European Union, has also summarized scientific reviews regarding biotechnology crops.


  • Aguilera J, Gomes AR, Olaru I (2013) Principles for the risk assessment of genetically modified microorganisms and their food products in the European Union. International journal of food microbiology
  • Atherton KT (2002) Safety assessment of genetically modified crops. Toxicology 181–182: 421-426
  • Beever D, Kemp C (2000) Safety issues associated with the DNA in animal feed derived from genetically modified crops. A review of scientific and regulatory procedures. Nutr Abstr Rev Series B: Livestock Feeds and Feeding 70: 175-182
  • Bernstein JA, Bernstein IL, Bucchini L, Goldman LR, Hamilton RG, Lehrer S, Rubin C, Sampson HA (2003) Clinical and laboratory investigation of allergy to genetically modified foods. Environmental health perspectives 111: 1114-1121
  • Betz FS, Hammond BG, Fuchs RL (2000) Safety and advantages of Bacillus thuringiensis-protected plants to control insect pests. Regulatory toxicology and pharmacology : RTP 32: 156-173
  • Brake DG, Evenson DP (2004) A generational study of glyphosate-tolerant soybeans on mouse fetal, postnatal, pubertal and adult testicular development. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 42: 29-36
  • Brake DG, Thaler R, Evenson DP (2004) Evaluation of Bt (Bacillus thuringiensis) corn on mouse testicular development by dual parameter flow cytometry. J Agric Food Chem 52: 2097-2102
  • Conner AJ, Glare TR, Nap J-P (2003) The release of genetically modified crops into the environment. The Plant Journal 33: 19-46
  • Devos Y, De Schrijver A, De Clercq P, Kiss J, Romeis J (2012) Bt-maize event MON 88017 expressing Cry3Bb1 does not cause harm to non-target organisms. Transgenic research 21: 1191-1214
  • Domingo JL, Giné Bordonaba J (2011) A literature review on the safety assessment of genetically modified plants. Environment International 37: 734-742
  • Eizaguirre M, Albajes R, Lopez C, Eras J, Lumbierres B, Pons X (2006) Six years after the commercial introduction of Bt maize in Spain: field evaluation, impact and future prospects. Transgenic research 15: 1-12
  • Flachowsky G, Chesson A, Aulrich K (2005) Animal nutrition with feeds from genetically modified plants. Archives of Animal Nutrition 59: 1-40
  • Fu T-J, Abbott UR, Hatzos C (2002) Digestibility of Food Allergens and Nonallergenic Proteins in Simulated Gastric Fluid and Simulated Intestinal FluidA Comparative Study. Journal of Agricultural and Food Chemistry 50: 7154-7160
  • Goodman RE, Hefle SL, Taylor SL, van Ree R (2005) Assessing Genetically Modified Crops to Minimize the Risk of Increased Food Allergy: A Review. International Archives of Allergy and Immunology 137: 153-166
  • Goodman RE, Vieths S, Sampson HA, Hill D, Ebisawa M, Taylor SL, van Ree R (2008) Allergenicity assessment of genetically modified crops; what makes sense? Nat Biotech 26: 73-81
  • Kuntz M, Ricroch AE (2012) Is it Time to Adjust the Current Regulatory Risk Assessment for GM Food and Feed? ISB news report
  • Ladics GS, Selgrade MK (2009) Identifying food proteins with allergenic potential: Evolution of approaches to safety assessment and research to provide additional tools. Regulatory Toxicology and Pharmacology 54: S2-S6
  • Lehrer SB, Bannon GA (2005) Risks of allergic reactions to biotech proteins in foods: perception and reality. Allergy 60: 559-564
  • Mendelsohn M, Kough J, Vaituzis Z, Matthews K (2003) Are Bt crops safe? Nature Biotechnology 21: 1003
  • Ricroch AE, Berge JB, Kuntz M (2011) Evaluation of genetically engineered crops using transcriptomic, proteomic, and metabolomic profiling techniques. Plant Physiol 155: 1752-1761
  • Schrøder M, Poulsen M, Wilcks A, Kroghsbo S, Miller A, Frenzel T, Danier J, Rychlik M, Emami K, Gatehouse A, Shu Q, Engel K-H, Altosaar I, Knudsen I (2007) A 90-day safety study of genetically modified rice expressing Cry1Ab protein (Bacillus thuringiensis toxin) in Wistar rats. Food and Chemical Toxicology 45: 339-349
  • Sinagawa-García SR, Rascón-Cruz Q, Valdez-Ortiz A, Medina-Godoy S, Escobar-Gutiérrez A, Paredes-López O (2004) Safety Assessment by in Vitro Digestibility and Allergenicity of Genetically Modified Maize with an Amaranth 11S Globulin. Journal of Agricultural and Food Chemistry 52: 2709-2714
  • Snell C, Bernheim A, Berge JB, Kuntz M, Pascal G, Paris A, Ricroch AE (2012) Assessment of the health impact of GM plant diets in long-term and multigenerational animal feeding trials: a literature review. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 50: 1134-1148
  • Sten EVA, Skov PS, Andersen SB, Torp AM, Olesen A, Bindslev-Jensen U, Lars K B-J, Bindslev-Jensen C (2004) A comparative study of the allergenic potency of wild-type and glyphosate-tolerant gene-modified soybean cultivars. APMIS 112: 21-28
  • Sweet J, Bartsch D (2012) National Research Programme NRP 59 “Benefits Risks of the Deliberate Release of Genetically Modified  Plants”: Synthesis and Overview Studies to Evaluate Existing Research and Knowledge on Biological Issues on GM Plants of Relevance to Swiss Environments. vdf Hochschulverlag AG an der ETH Zurich, Zurich
  • Tang X, Han F, Zhao K, Xu Y, Wu X, Wang J, Jiang L, Shi W (2012) A 90-Day Dietary Toxicity Study of Genetically Modified Rice T1C-1 Expressing Cry1C Protein in Sprague Dawley Rats. PLoS ONE 7: e52507
  • Taylor M, Hartnell G, Lucas D, Davis S, Nemeth M (2007) Comparison of broiler performance and carcass parameters when fed diets containing soybean meal produced from glyphosate-tolerant (MON 89788), control, or conventional reference soybeans. Poultry science 86: 2608-2614
  • Taylor SL, Hefle SL (2001) Will genetically modified foods be allergenic? The Journal of allergy and clinical immunology 107: 765-771
  • Taylor SL, Hefle SL (2002) Genetically engineered foods: implications for food allergy. Current opinion in allergy and clinical immunology 2: 249-252
  • Report of the EFSA GMO Panel Working Group on Animal Feeding Trials (2008) Safety and nutritional assessment of GM plants and derived food and feed: The role of animal feeding trials. Food and Chemical Toxicology 46, Supplement 1: S2-S70
  • United States A, Plant Health Inspection Service DAP (1997) Petition for determination of nonregulated status : high oleic acid transgenic soybean sublines derived from transformation event 260-05. DuPont, Wilmington, DE
  • Wang Z-h, Wang Y, Cui H-r, Xia Y-w, Altosaar I, Shu Q-y (2002) Toxicological evaluation of transgenic rice flour with a synthetic cry1Ab gene from Bacillus thuringiensis. Journal of the Science of Food and Agriculture 82: 738-744




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