Much to the surprise of about 30% of Americans, we have been eating food made from genetically modified (GM) crops since 1998 when the first Flav-Savr tomato was introduced into US supermarkets. Yet, even with hundreds of million people eating GM foods for more than a decade, controversy over this technology remains high. Is there still a reason to be concerned about GM crops? Are they dangerous? There are a number of groups trying to make this case.
What's the Big Concern with GM Food?
Anti-GM advocates cite potential health concerns and charge that GM foods have not been adequately tested to prove safety. The main concerns constellate around concern of negative reactions to the specific gene inserted into the genetically modified plant. Scenarios describe possible toxic effects from plant made resistant to pesticides like Bacillus thuringiensis (Bt) or glyphosate, or an allergic reaction that might occur if someone has a peanut allergy and consumes a crop, such as soy bean, with a foreign nut gene.
Essentially, the concern over GM technology, centers on potential risks or unexpected side-effects that might occur from using the technique. It is a judgment on the current state of the science to be able to carry out these changes safely. Do we know enough about what we are doing?
Is There Evidence of a Problem with GM Crops?
To bolster the point that there is reason to be concerned over the potential risk, anti-GM groups typically cite a few studies where abnormalities appeared to occur in animals fed GM crops.
Probably the most cited examples is Arpad Pusztai's study in the Lancet noting GM potatoes expressing a protein thickener from the snowdrop flower had negatively affected the rat gastrointestinal tract. Just prior to publication in 1999, Dr. Pusztai appeared on a British TV show briefly describing the results and expressing concern that citizens are being used as guinea pigs. Dr. Pusztai's TV appearance created a firestorm of controversy about GM food.
However, though often touted as an advocate against GM food, the significance of Dr. Putztai's study is a much more modest. The potato in the study was not developed for human consumption. It was a test model designed specifically to be poisonous to insects and the study itself was somewhat flawed. However, Dr. Putztai's experiment did show that genetically engineered modifications have the potential to be dangerous. His main concern, as stated in the 2008 interview with the Guardian, was primarily to push for more testing of genetically engineered food, not make a blanket statement about the hazardous of GM food. His issue was to elevate the science above the political and economic drivers pushing GM technology.
Other studies often cited by anti-GM groups include Fared and Sayed's "Fine Structural Changes in the Ileum of Mice Fed on δ-Endotoxin-Treated Potatoes and Transgenic Potatoes", the article by Vecchio, et al., "Ultrastructural Analysis of Testes from Mice Fed on Genetically Modified Soybean", Gilles-Eric Séralini reanalysis of Monsanto's GM-corn data in "A Comparison of the Effects of Three GM Corn Varieties on Mammalian Health," Aris and Leblanc's study, "Maternal and Fetal Exposure to Pesticides Associated to Genetically Modified Foods in Eastern Townships of Quebec, Canada," and a few others.
Do The Studies Suggest a Reason to Be Worried about GM Foods?
It is relatively easy to find a number of critiques for these publications on the Web. For example here is a criticism of the last study above authored by Aris and Lelance. A more important point, though, is that, with any scientific study, a single result proves little. There are no perfect studies so it is important to look that overall body of scientific literature published. If this analysis is done, the most notable characteristic of the published articles cited by the anti-GM groups is simply that there are simply not that many of them. These studies are really outliers.
Many of the groups seem to go great lengths expounding on the amount of science showing the danger of GM food. However, in the end, as can be seen from websites such as GM Watch, Say No to GMOs, and, Jeffrey Smith's Institute for Responsible Technology much of the information about the proposed hazards of GM food is rhetorical and references secondary reports rather than primary studies.
The science, as a whole, does not suggest any particular hazards generally related to GM foods. The limited publications cited by anti-GM advocates on adverse reactions under discrete experimental conditions provide some support that there may be unrealized effects from these foods. However, until data from some of these studies is confirmed by the wider scientific community, results from these few specific studies may reflect other experimental variables or have occurred because of a poorly designed experiment. After over twelve years in supermarkets, the anti-GM position essentially remains the belief that not enough is known to ensure GM crops are generally safe.
Is There Good Science on the Safety of GM Food?
While anti-GMO groups have industriously put together extensive amounts of material to argue the proposition that GM foods are dangerous, virtually all of the concerns and claims have been extensively addressed. Sites such as a AgBioWorld and Academics Review provide specific analysis of each point brought up by these groups, and scientists such as the opinion in the NY Times by Dr. Nina Federoff and Cara Santa Maria's Huffington Post interview with Professor of Plant Biology Kevin Folta from the University of Florida offer a more general overview GM technology.
However, the most comprehensive and informative sources for real science on GM-Food safety are perhaps sites developed by European government agencies such as GMO-Compass and GMO Safety from the German Ministry of Research. The European Union, which has had a virtual ban on GM Food since the start of the century, has made a massive effort to study GMOs.
A Reasonable Perspective on the Safety GM Food
Most of the concerns around food from GM crops focus the potential risk of unexpected side effects. However, similar or even higher levels of risk occur with other plant breeding methods such as mutation breeding using radiation or chemical to cause multiple mutations to create plants with specific traits. This approach was recently used to produce a new orange strain.
Probably, the more pertinent reason for concern about GM food is expressed in the introduction of the Decade of European Funded GMO Research Report by Dr. Marc Van Montagu, Chairman of the Ghent University Institute of Plant Biotechnology. Dr. Van Montagu notes that "The fact that humans can ‘engineer’ a gene from a species of one kingdom to produce a species of another has fuelled imaginations and frightened the public." He goes on to note that, "Proving that GM Crops are safe is not easy....Science can certify the existence of danger, but not its absence."
The fear of GM food is really of the fear of the unknown, and that can only be addressed by more familiarity. The scarcity of evidence of specific health problems related to GM-food, which has been around sold for almost 15 years, increases this familiarity and is gradually undermining the source of the concern. The recent productive dialog between scientists and anti-GM protesters over field trials of genetically modified potatoes in England suggests that some the fear of GM foods is being replaced by more practical discussion of the risks and benefits of this technology. Hopefully, the trend will continue.