Save the lab rats!

Last week I wrote about studies that debunked the myth that GMO crops use fewer pesticides than other traditional farming methods.  This week I will continue to dispel GMO myths and tackle the biggest one of all…

Myth #2: GMOs are safe to eat. 

“There is more than a casual association between GM foods and adverse health effects…. Multiple animal studies show significant immune dysregulation, including upregulation of cytokines [protein molecules involved in immune responses] associated with asthma, allergy, and inflammation.” – American Academy of Environmental Medicine

L-tryptophan hit the news in 1989 when it was blamed for killing several people and permanently harming hundreds of others.  L-tryptophan was produced using genetically modified bacteria and resulted in a disease called Eosinophilia Myalgia Syndrome (EMS).  The symptoms of EMS included overproduction of white blood cells, severe muscle pain and paralysis.  This toxic L-tryptophan was traced back to a Japanese company and although there is still debate as to whether the toxicity of L-tryptophan was due to genetic engineering or a flawed manufacturing, the FDA responded to the crisis by banning L-tryptophan.  Eventually the CDC conducted a study and concluded that only the Japanese manufacturer had an issue with toxins within its manufactured L-tryptophan.   Proponents quickly criticized the CDC stating that this same tragedy is likely to occur again because testing standards are not up to par to detect these types of toxins given the similarity and purity of the synthetic product to its non-GMO counterparts.  

A genetically modified Bt maized called StarLink was criticized in 2000 when people started to report allergic reactions.  The reports were investigated by the CDC and the CDC later ruled that the blood tests it took and studied did not provide evidence that allergic reactions were associated with StarLink.  The investigation was criticized and later reviewed by a panel convened by the EPA.  The panel pointed out that CDC researchers had made several errors in their testing and concluded that there was a “medium likelihood” that a protein within StarLink maize is an allergen. 

GMO supporters have also claimed that a major benefit of GMOs is that they are more nutritious than traditional crops.  Many studies are finding that the opposite is true and GMO crops are actually less nutritious than their counterparts.  GM rice varieties have shown nutritional deficiencies when compared with non-genetically modified counterparts (that were grown in the same conditions).  GM rice showed decreased levels of vitamin E, protein and amino acids and proved that non-genetically modified rice was superior (1). 

As I discussed last week in my blog, some GM crops are engineered to produce a form of insecticide known as Bt toxin.  In a 2012 study, genetically engineered Bt toxins were found to be toxic to human cells (2).  One specific type of Bt toxin killed human cells.  GM lobbyers responded by saying that this type of study (in vitro) did not accurately reflect what happens in a living human or living animal that eats GM Bt crops; however, other studies have found that these types of crops have had adverse effects on lab animals.  Rats fed Bt maize grew more slowly and showed higher levels of certain fats in their blood when compared to rats fed a controlled diet (3).  They also suffered problems with their livers and kidneys.  The authors state that it could not be concluded that this maize is safe and that long-term studies are needed to investigate these consequences further. 

In fact, a common defense of GMO supporters is that long-term studies do not exist. Governments around the world are not requiring these types of studies in order for us all to determine the long-term effects GMOs potentially have but currently, no long-term tests on GM crops or foods are required by regulatory authorities anywhere in the world.  Reproductive and multigenerational tests, which are necessary to discover effects of GM crops or foods on fertility and future generations, are also not required (4).  So let’s give both sides the benefit of the doubt here and say there’s enough evidence to counterbalance both sides.  Would we still want to take our chances given all the unknowns?  Is manipulating our food supply worth it given our successful history of cross-breeding plant (hybrid) methods? What about those potentially damaging environmental effects too? India, Japan, Australia and the European Union aren't taking any chances.  

(1)      Jiao Z, Si XX, Li GK, Zhang ZM, Xu XP. Unintended compositional changes in transgenic rice seeds (Oryza sativa L.) studied by spectral and chromatographic analysis coupled with chemometrics methods. J Agric Food Chem. Feb 10 2010; 58(3): 1746-1754.

(2)      Mesnage R, Clair E, Gress S, Then C, Székács A, Séralini G-E. Cytotoxicity on human cells of Cry1Ab and Cry1Ac Bt insecticidal toxins alone or with a glyphosate-based herbicide. Journal of Applied Toxicology. 15 Feb 2012.

(3)      Séralini GE, Cellier D, Spiroux de Vendomois J. New analysis of a rat feeding study with a genetically modified maize reveals signs of hepatorenal toxicity. Archives of Environmental Contamination and Toxicology. May 2007; 52(4): 596–602.

(3)      Séralini GE, Mesnage R, Clair E, Gress S, de Vendômois JS, Cellier D. Genetically modified crops safety assessments: Present limits and possible improvements. Environmental Sciences Europe. 2011; 23(10).