Twenty years after their arrival on the market, 85% of GMOs across the world are created to resist herbicides such as Monsanto's glyphosate-based Roundup (1). The use of this type of crop has increased the use of herbicides, particularly those containing glyphosate. glyphosate is used with virtually all GMO crops, and is the highest selling pesticide in the province of Québec. Glyphosate sales have increased from 71% between 2006 and 2011 (2) in spite of the governement's intent to reduce pesticides use in Québec. In October 2015, Radio-Canada used the revealing headline: "Québec a perdu le contrôle des pesticides" (Québec loses control over pesticides). Glyphosate and dozens of other pesticides end up in our food and in our environment, particularly our water (3), presenting important risks to the health of Quebeckers.
There are few studies examining the health risks of GMOs but there are many studies about negative effects associated with pesticides use, particularly glyphosate. The safety of GMOs has not yet been demonstrated and there is an increasing recognition of their potential risks, particularly because of GMO resistance to pesticides.
GMOs could have some impacts on our health. However, very few studies have been conducted on these risks, partly because GMO patents restrict independant research. Let's see why there are so few studies on GMOs and what their potential impacts on health could be.
One of the important factors contributing to the small number of studies conducted on the impact of these biotechnologies is the fact that we are unable to study patented GMOs without the authorisation from the companies that hold the patents (4). Lobbying, corporate funding for research and education, and disparagement of critics through public relation firms also help explain why the number of studies and critics are limited. (5)
In addition, Health Canada approves GM foods without testing their safety. In 2001, the Royal Society of Canada’s Expert Panel on the Future of Food Biotechnology recommended a different approach for evaluating the risks of GMOs (6). In 2003, the Commission of Ethics of Science and Technology of Québec provided a similar recommendation, inviting the government of Québec to make representations to the federal government of Canada so the "regulatory requirements for the approval, control and long-term monitoring for GMOs, no matter what their application, are higher than those that already exist for new products" (7).
Even though GMOs have been on the market for more than 20 years, scientific literature on GM foods, independent and long-term studies in particular, remain limited and contradictory. In 2013, almost 300 scientifics jointly stated that there is still no "scientific consensus" on GMO safety and that "decisions concerning the future of your food system and of our agriculture cannot be based on the fraudulent and non representative claim that a "scientific consensus" does exist regarding GMO safety."
In 2001, the Royal Society of Canada Expert Panel on the Future of Food Biotechnology (6) identified three categories of potential risks to human health :
Each GM food needs to be examined for these risks. Many existing studies show that GM foods can actually be toxic, allergenic or entail changes in nutritional content (9).
Among the potential health risks of GMOs:
Many studies have identified signs of toxicity of GMOs on kidneys and liver, for example. It can notably indicate the emergence of chronic diseases. Other studies have demonstrated toxic effects such has damage to organs (9).
Some plants are genetically modified to produce Bt toxins (from a soil bacteria called Bacillus thuringiensis) in order to kill insects. Bt proteins are presumed to not be harmful to humans but somes studies challenge the assumption that Bt protein are degraded in the human gut (10). A study conducted in 2011 by Aziz Aris and Samuel Leblanc from the Université de Sherbrooke, in Québec, indicated that a Bt toxin (Cry1Ab) was present in the blood of pregnant mothers and their fetuses (11).
The toxicity of herbicides used with the majority of GM crops also needs to be assessed with long-term studies such as that on NK603 GM conducted during two years by Gilles-Éric Séralini, molecular biologist for the Université de Caen in France. This is the most-in-depth study ever conducted on a GM food and related pesticides (12).
Reproducing this and other studies may confirm or invalidate the results. Conducting further testing could confirm impacts human health and help identify causes. Unfortunately, long-term studies are rarely conducted by independent bodies, including government departments.
Food allergies are caused when the body’s immune system reacts to food proteins as if they are harmful (13). An allergic response could be triggered by exposure to a foreign protein that has never been consumed in food before or to an increased level of naturally occurring allergens (an increase in the endogenous allergenicity of a food) triggered by the insertion of new genetic material as in some GMOs.
The cause of the increase in food allergies (14) in North America is largely unknown (8). The question of allergenicity with GM foods remains problematic for risk assessment and, as the Royal Society of Canada’s Expert Panel pointed out, the likelihood of allergic risk will rise with an increased range of GM foods on the market and increased dietary exposure (6).
Approving the use of GMO produced with antibiotic resistant marker genes is internationnaly discouraged because of the risk - though low - that these genes could transfer to intestinal bacteria. Yet, most GM foods on the market have been created this way, including the non-browning GM apple approved in 2015 in Canada (16).
Antibiotic resistance in disease-causing bacteria is an increasingly serious global problem that puts the future of antibiotic medical treatment at risk. Bacteria develop resistance to antibiotics by creating antibiotic resistance genes through natural mutation and the concern is that bacteria living in the guts of humans and animals could pick up an antibiotic resistance gene from a GM food before the DNA is completely digested. While both the World Health Organization and the European Commission describe the probability as low, they discourage the use of such genes (17). The European Commission also notes that, “if GM plants with antibiotic resistance genes are planted over a very large area, the rare event of gene transfer to other organisms (horizontal gene transfer) could become significant” (18). Bear in mind that there is a large surface of GM crops grown in Québec, amounting to more than 500,000 hectares in 2014 (19).
The Royal Society of Canada’s Expert Panel noted the necessary role of considering dietary exposure in risk assessment: “Toxicological effect is related not only to the food we are exposed to, but to the amount of exposure as well” (20). The panel said that the potential risk of developing toxic or allergic reactions to GM foods would likely rise with increased exposure (21).
However, Canadian government regulators do not know our level of dietary exposure to GM foods because there is no monitoring of human consumption of GM foods in Canada.
Pesticides pose significant risks for health and the environment. Studies on this subject have multiplied, in particular about glyphosate, which is the primary ingredient of Monsanto's Roundup. This product is used to a significant extent in most GM crops. As mentioned before, it is the most sold pesticide in Quebec, and its sales have increased from 71% between 2006 and 2011 (2).
Among the impacts on health associated with the use of pesticides in general and of those used in GM crops:
At a general level, some studies indicate that being exposed to even a very small amount of pesticides can lead to an increased risk to develop cancer, notably in young children and young adults (23). Professor Howard is one of the professors responsible for this study. He says: “environmental pollutants, in particular synthetic pesticides and organochlorines who are hormone disrupting substances, can constitude major factor risks for hormone-dependent malignant tumors (...) we now should concentrate on reducing exposition to these problematic chemical products."
As regards to glyphosate, main ingredient of Monsanto's Roundup formula, it has been classified as a probable human carcinogen (category IIA) by the International Agency for Research on Cancer (IARC) in 2015 (24).
Of all chemical product expositions that can be linked to Parkinson’s disease, pesticides are the ones that represent the clearest link. Recent research has shown increased rates of Parkinson’s disease in persons who have been exposed to pesticides for long periods in their working environment (25). Since May 2012, in France, due to pressure from dockers and farmers, Parkinson’s disease is considered an occupational disease. It is the second degenerative disease linked to the use of pesticides recognized as such in France, after Alzheimer's disease (26).
Many studies focus specifically on links between glyphosate and neurodegeneration conditions like Parkinson's (27) (28).
During recent years, scientifics have become more worried about all the chemical products that act as endocrine disruptors since they interfere with hormones in the body, even in very low doses. Especially during pregnancy and puberty, endocrine disruptors can cause irreversible effects, even if no toxicity sign is immediately present (29). To date, 127 pesticide-type active substances authorised in Europe are believed to be endocrine distuptors, and Roundup, the famous herbicide, is among them.
Studies emphasize the impacts of Monsanto's glyphosate-based Roundup herbicide on the endocrine system, which could also lead to particularly harmful effects on reproduction and the number of sperm in the semen (30).
Children exposed to significant concentrations of pesticides found in fruits and vegetables in the United States are more likely to suffer from de attention deficit disorder with or without hyperactivity (ADHD). This has been shown by a scientific study conducted in Canada and in the United States (31).
A new study, published in 2015, has demonstrated a positive link between the use of glyphosate-based pesticides and the increase of ADHD cases in the populations neighboring areas of utilization (32). New North-American studies conducted among farming families have established links between the use of glyphosate and higher rates of ADHD in children (33).
In the past decade, certain countries in South America have also seen a considerable growth in the production of GMOs created to resist to glyphosate-based pesticides. Reports from these areas raise serious concerns about glyphosate. In Argentina, in the province of Chaco, where GM glyphosate-resistant soya is grown, congenital defects have tripled over the last ten years (34). Another study conducted in a Paraguayan hospital, in 2006-2007, has shown that women living less than one kilometer from soya fields treated with pesticides were twice as likely to give birth to a child with malformation (35).
Women exposed to certain pesticides during pregnancy are more at risk to give birth to an autistic child. These are the findings of a study conducted by the Oakland's Institute of Public Health and by the School of Public Health, at the University of Berkeley (36). Scientists have revealed a risk of giving birth to autistic children that is six times higher than for women not living nearby agricultural areas. Dr. Stephanie Seneff, researcher at the Massachussetts Institute of Technology (MIT) goes so far as to allow a correlation between the growing use of glyphosage-based pesticides and the development of autism amongst American children. She presents alarming figures: from 1 out of 5,000 in 1975, the number of autistic children would have increased to 1 ouf of 68 in 2010 (37).
A study carried out on a population of women with fertility issues living in rural areas reveals that the predominant factor lies in the preparation and application of herbicides (the risk is 27 times higher) and that this risk would be much higher than the risk associated with having a male partner over the age of 40 (4.5 times) or steady weight gain in adult life (3.5 times) (38).
Glyphosate-based herbicides would have a particularly detrimental effect on reproduction and number of sperm in the semen (30).
For more information, visit www.vigilanceogm.org
(1) James, C. (2015). Global Status of Commercialized Biotech/GM Crops: 2014, ISAAA brief No. 49. International Service for the Acquisition of Agri-biotech Applications (ISAAA): Ithaca, NY.
(2) Report on Sales of Pesticides in Québec 2012, Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques (MDDELCC)
(3) Présence de pesticides dans l’eau au Québec 2011-2014 (in French), Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques (MDDELCC) http://www.mddelcc.gouv.qc.ca/pesticides/mais_soya/portrait2011-2014/rapport2011-2014.pdf
(4) Extract from the Position de l’Ordre des agronomes du Québec sur les organismes génétiquement modifiés (in French), January 28, 2000, p. 6
(5) Sheffer, P. (2009-2010) L'influence de l'industrie agroalimentaire dans le domaine de la nutrition et la place de l'esprit critique dans la formation des diététiciens (Mémoire de master recherche de Sciences de l’éducation), Laboratoire Experice, Université Paris 8, p.
(6) An Expert Panel Report on the Future of Food Biotechnology. (2001). Elements of Precaution: Recommendations for the Regulation of Food Biotechnology in Canada.
(7) For the ethical management of GMOS. (October 2003). Commission de l’éthique, de la science et de la technologie
(8) Statement: No scientific consensus on GMO safety, statement made by more than 300 researchers, published via European Network of Scientists for Social and Environmental Responsibility, January 2015
(9) Fagan, John, Michael Antoniou, and Claire Robinson. 2014. GMO Myths and Truths. Second edition, Version 1.0. Earth Open Source. Page 128.
(10) Fagan, John, Michael Antoniou, and Claire Robinson. 2014. GMO Myths and Truths. Second edition, Version 1.0. Earth Open Source. Page 182.
(11) Aris, Aziz and Leblanc, Samuel. 2011. Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada. Reprod Toxicol. May; 31(4): 528-33.
(12) Séralini GE, E. Clair, R. Mesnage, et al. 2012. [RETRACTED:] Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize. Food Chem Toxicol. 50:4221-4231.
(13) Codex Alimentarius, 2013. Guideline for the conduct of food safety assessment of foods derived from recombinant-DNA plants, CAC/GL 45-2003. Paragraph 43.
(14) Canada just started to study the prevalence of food allergies, but the Centers for Disease Control and Prevention in the United States report that in children under 18 years old, the prevalence of allergies has increased from 3.4% in 1997 to 5.1% in 2009-2011. See Kristen D. Jackson, LaJeana D. Howie, Lara J. Akinbami. 2013. Centers for Disease Control and Prevention. National Center for Health Statistics Data Brief Number 121, May. Trends in Allergic Conditions Among Children: United States, 1997–2011
(15) Tucker, Erika. 2014. Why are potentially deadly food allergies in kids on the rise? Global News. October 17.
(16) Développement de résistance aux antibiotiques, Source d’information sur les organismes génétiquement modifiés du Gouvernement du Québec http://www.ogm.gouv.qc.ca/sante_et_environnement/sante/risques_potentiels/dev_resistance_antibiotiques.html
(17) World Health Organization, Frequently asked questions on genetically modified foods. Accessed August 23, 2015.
(18) European Commission, GMO Compass. Food Safety Evaluation Antibiotic Resistance Genes: A Threat? Accessed August 23, 2015.
(19) In 2014, Quebec has sown 502,000 hectares of GMO (including corn and soya, but excluding canola in absence of complete statistics)
(20) An Expert Panel Report on the Future of Food Biotechnology. 2001. Elements of Precaution: Recommendations for the Regulation of Food Biotechnology in Canada. Page 46. https://rsc-src.ca/sites/default/files/pdf/GMreportFR.pdf
(21) Ibid. Pages 47 an 55.
(22) Definition of pesticides on the Ministère du Développement durable, de l’Environnement et de la Lutte aux Changements climatiques (MDDELCC) Web Site. April 11, 2016, http://www.mddelcc.gouv.qc.ca/pesticides/apropos_en.htm
(23) JOHN A. NEWBY BSc & C. VYVYAN HOWARD MB, ChB, PhD, FRCPath Environmental influences in cancer aetiology Journal of Nutritional and Environmental Medicine 2006, 1 59,
(24) Kathryn Z Guyton & al., on behalf of the International Agency for Research on Cancer Monograph Working Group, IARC, Lyon, France. Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate
(25) Parkinson’s Disease Foundation
(26) Le lien entre la maladie de Parkinson et les pesticides officiellement reconnu
(27) Gui YX and al. Neurotoxicol Teratol. 2012 May-Jun; Glyphosate induced cell death through apoptotic and autophagic mechanisms
(28) Anthony Samsel and Stephanie Seneff, Entropy 2013, 15(4), 1416-1463, Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases
(29) Zoeller RT et al (2012) Endocrine-Disrupting Chemicals and Public Health Protection: A Statement of Principles from The Endocrine Society Endocrinology Vol. 153 pp. 4097–4110
(30) Clair, É., et al. A glyphosate-based herbicide induces necrosis and apoptosis in mature rat testicular cells in vitro, and testosterone decrease at lower levels. Toxicol. in Vitro (2012), doi:10.1016/j.tiv.2011.12.009
(31) Maryse F. Bouchard and al. may 2010, Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides
(32) Fluegge KR, PLoS One. 2015 Aug 19, Glyphosate Use Predicts ADHD Hospital Discharges in the Healthcare Cost and Utilization Project Net (HCUPnet): A Two-Way Fixed-Effects Analysis
(33) Garry VF et al. (2002) Birth defects, season of conception, and sex of children born to pesticide applicators living in the Red River Valley of Minnesota, USA. Environmental Health Perspectives Vol. 110 pp. 441-449
(34) López SL et al (2012) Pesticides Used in South American GMO-Based Agriculture: A Review of Their Effects on Humans and Animal Models. Advances in Molecular Toxicology Vol. 6 pp. 41-75
(35) Benítez-Leite S, Macchi ML & Acosta M (2009) Malformaciones congénitas asociadas a agrotóxicos [Congenital malformations associated with toxic agricultural chemicals]. Archivos de Pediatría del Uruguay Vol. 80 p. 237-247
(36) Risk factors for female infertility in an agricultural region , Greenlee AR, Arbuckle TE, Chyou PH, Epidemiology. 2003 Jul;14(4):429-36.
(37) Clair, É., et al. A glyphosate-based herbicide induces necrosis and apoptosis in mature rat testicular cells in vitro, and testosterone decrease at lower levels. Toxicol. in Vitro (2012), doi:10.1016/j.tiv.2011.12.009