Category Archives: Rachel Warburton
Insect-Resistant Genetically Modified Rice in China
Indirect Effects of GMOs on Biodiversity
Genetically engineered canola populations in the United States
Benefits and concerns of the use of GMOS in Africa
Possible Improvements of Genetically Modified Organisms
Regulation of genetically modified crops is an ongoing international debate. The need for regulation is preliminarily for assessing health risks and examining the adverse health effects that some genetically modified organisms have been linked to. In an article produced by Environmental Sciences Europe, Gilles- Eric Séralini et al. (2011) examine the current tests being done for regulation purposes. In the article the validity of these tests are questioned due to a lack of what the authors seem to see as essential requirements for lab tests. The lab tests are conducted on mammals, the majority being mice and rats, mainly by biochemical blood and urine variables. The animals are fed the GMOs over anywhere between 28 to 90 day periods. According to Séralini et al. 90 days is an insufficient amount of time to evaluate chronic toxicity. Despite this fact, the test results still connote liver and kidney problems as end points of GMO diet effects. Residues of certain GMOs such as bt corn have been found and linked to many of these help problems. Bt corn is a genetically modified type of maize with the bacteria Bacillus thuringiensis inserted inside of the corn seed in order to kill Lepidoptera larvae and therefore used as an alternative to spraying insecticides. Other adverse health effects are discovered along with a discrepancy between sexes, possibly due to interactions of pesticides to different hormones. A suggestion by Séralani et al. is to acknowledge sex differences when conducting the research. Many other suggestions are made on how to improve the testing regime for regulation and overall health of consumers. Rachel Warburton
Séralini, E.G., Mesnage, R., Clair, E., Gress,S., Spirooux de Vendömois, J., Cellier, D.,2011. Genetically modified crops safety assessments: present limits and possible improvements. Environmental Sciences Europe 23, 1-10.
The regulation on GM foods is much stricter in the European Union than it is in most other countries that utilize them. The European Food Safety Authority (EFSA) has its own GMO panel and working group which comes up with the testing regulations. Much of the current data come from research conducted by affiliates of the biotech industries, thus making the data possibly biased or skewed. For example it was shown that none of the biotech industry-funded research showed untoward effects of Bisphenol A, an organic compound found in some GMOs, yet 90% of government- funded studies showed health hazards with the compound. In this same study the mice chosen to be tested on were found to be insensitive to estrogen, a problem when trying to differentiate reactions between the sexes. Hundreds of other lab animals had previously been rejected for this study due to Good Laboratory Practices (GLP) which sets standards for lab tests. The FDA and EFSA base many of their decisions on GLP, yet GLP is based on primitive templates which pose a problem because they don’t take into account recent environmental sciences. Thus a gap between scientific knowledge and regulations is created.
The gap grows even wider by the lack of regulation despite the scientific evidence that has come from these studies. In the chronic or sub chronic toxicity studies in mammals fed with GM soybean and maize, which represents more than 80% of edible GMOs, almost all of the results came out to be identified as “controversial results” or “statistical differences”. Normal pesticide testing goes on for a 2-year period in order to truly detect the side effects yet this pesticide-containing-GMO testing lasts less than three months. This is sure to lead to “controversial results” and “statistical differences”.
As mentioned earlier, some liver and kidney problems were easily detected in the three-month period, though they are unsure whether they can fully be attributed to the GMO diet. In a meta-analysis of statistical difference with appropriate controls in feeding trials, 43.5% of all variables were disrupted in male kidneys, while the kidneys of the female counterparts were only 26%.
Roundup is an herbicide containing the active ingredient glyphosate. Glyphosate is the most widely used herbicide in the United States and Roundup has been the number one selling brand name herbicide since 1980. Many plants, such as most soybeans, canola, wheat, and cotton have been genetically modified to be “Roundup Ready”, meaning they are resistant to the herbicide while the weeds around them are not. Roundup Ready plants now account for 80% of GMOs and the residue, mainly composed of glyphosate and its metabolite AMPA (both of which contain different toxins) have been linked to human placental, embryonic and umbilical cord cells, thus having the ability to affect the reproductive system. Roundup also has the ability to stabilize glyphosate and allow it to penetrate through cells, which eventually changes the androgen/estrogen ratio, possibly explaining the difference in the results of the sexes and emphasizing the importance of testing each sex individually as Séralini et al. has done.
Current toxicity testing methods, also called Toxotests, on GMOs is very similar to those of classical toxicology. The feeding tests are based on the “no observed adverse effect level” along with the “lowest observed adverse effect level” approach, both of which are not specific enough and does not recognize that there is not one single chemical in GMOs but several unidentified metabolites. Séralini et al. suggests to perform the Toxotests on three mammalian species versus just rodents and to prolong the 90-day tests with a control and three normal doses of GM in the diet, rising at an exponential and steady rate.
Other suggestions for improvement include expanding the sample size of the testing group and following the series of steps posed by the EFSA for statistical analysis. Some of those steps include obtaining and modeling the growth curves and feed consumption evaluated by non-linear decline, integrating water consumption as a follow-up factor to better comprehend kidney and urine data and also using dose-response predictions. Since there is no traceability of GMOs in the United States, despite the fact 97% of GMOs are cultivated on the North and South American continent, there have been few tests conducted on humans. The traceability of animal products, on the other hand, is much more feasible and necessary if we wish to investigate GMOs in our food chain.
All in all it is evident there needs to be more transparency to consumers along with regulation of the products. The research needs to be more extensive as well, especially considering several billion people in the world have interacted with GMOs in some way or another. Séralini et al. finalizes the article by saying that the main ways to improve the current research techniques are to extend the time period from 90 days to 2 years, use mature rats, utilize the improved Toxotest approach and include sexual hormone assessments.
The Future of Genetically Modified Crops
Genetically modified crops allow larger quantities of certain foods to be made at a quicker rate compared to naturally grown seeds and crops. Reasons for this vary but include plant-produced insecticides and herbicide and the ability to grow in a broader range of climates. A review published in the African Journal of Agricultural Research written by Kamil Ekici et al. (2011) discusses the potential health effects along with an explanation on the labeling requirements and methods for detecting GMOs. GM crops have been around for no more than 20 years and weren’t approved in the United States until 1992. Since then the United States has become on the top producing and consuming nations of GMOs, despite the fact little regulation of GM crops is implemented in the United States, unlike European countries which have strict statutes in place. Although they have helped to speedily feed more cattle with soybean and maize GMOs along with other crops, there have been many studies on the adverse health effects of GMOs, such as links to antibiotic resistance, presence of toxins, fungi or metals, along with the possibility of increased cancer risk and new allergens (Bakshi et al. 2003). In this article Ekici and colleagues from the Department of Food Hygiene and Technology at Veterinary College and University of Yuzuncu Yil, both in Van, Turkey, construct a certain perspective of genetically modified crops by investigating health effects, socio-cultural beliefs for and against GMOs along with labeling requirements and stating strategies to detect GMOs. –Rachel Warburton
Ekici et al., 2011;Gizzarelli et al., 2006; Warner, 2002; Heckmann et al., 2006; Dean and Shepherd, 2007 Hurst et al. 1999
Along with the adverse health risks already stated in the first paragraph, many countries find the idea of GMOs as going against socio-cultural and ethical issues across national and international lines. Other countries, such as Turkey, already regulate the labeling, tariffs and prices for retail GMOs (Emiroglu 2002). These regulations place general obligations on tracing all of the ingredients in all stages of food production. In Europe labeling is required if there are health or ethical concerns and the EU law also mandates labeling when the product is not equivalent to the existing foods (Dean and Shepherd 2007).
As for detection of GMOs, the most prominent way to conclude whether the product contains a GMO is by performing a Polymerase Chain Reaction (PCR). PCR enables the detection of specific strands of DNA by making millions of copies of a target genetic sequence. If the sequence is specific to a certain GMO the positive PCR test tells you that the GMO is present. Other methods include nucleotide-based amplifications, protein-based and enzymatic techniques.
According to Ekici et al. most government agencies find GM crops beneficial to the consumer, while it is still up in the air whether the consumer feels the same. The European Union has more reservations about GMOs and thus has more requirements for the processing and creation thereof.
Overall there are a few contrasting ideas of GMOs and what will become of them in the future. Proponents of them see them as the “technology of the future” by promising to “solve the problem of world hunger”. Other supporters believe the genetic modification could lead to new and bettered products with sought-after attributes such as seedless fruit. The main arguments against GMOs are those stated earlier—health risks, socio-cultural beliefs, and environmental problems mostly. As articulated by Ekici et al., consumer confidence declines when a product is labeled with the inclusion of GM products and therefore food companies tend to be weary to use GM products. Nonetheless as the world continues to grow exponentially the need for food at a quicker rate will increase as well and therefore the use of GM crops will also increase.