There has not yet been a robust and thorough search into the potentially harmful effects of GM [genetically modified] foodstuffs on human health.
- British Medical Association, November 20, 2002[i]
Summary
Infants and children are particularly vulnerable to any potential health risks from consuming genetically engineered or GE foods (also called genetically modified or GM foods). Possible health concerns raised by GE include the creation of new allergens and toxins, nutritional changes and the threat of antibiotic resistance. We do not know if any of the GE foods currently on the market pose health risks. There are only a few preliminary, independent scientific studies that examine possible human health effects [ii] and the lack of scientific literature itself raises critical questions about the science and regulation of genetic engineering. There are also social and environmental issues raised by the technology that must be considered in relation to their impact on health, and child health in particular.
Introduction
In Canada, the first genetically engineered crop variety was approved in 1995. Canadian regulatory agencies (Health Canada and the Canadian Food Inspection Agency) have approved almost 50 GE crop varieties for environmental release and human consumption. These represent only 9 food crops and not all of these are currently on the market. As of January 2003, there are three GE crops grown and consumed in Canada – corn, canola and soy. [iii] These appear, for the most part, as ingredients in processed foods (canola oil in frozen dinners and soy lethicin in chocolate bars, for example), and are used for animal feed. Most importantly for the purposes of investigating the impact on child health, GE soy appears as a major ingredient in infant formula as well as an ingredient in baby cereals and baby biscuits.
What is Genetic Engineering?
Genetic engineering is a new technology that enables scientists to isolate genes and move them from one organism directly into the DNA of another. This means that genes can be transferred from one species to an entirely unrelated species, even from animal to plant kingdoms. For example, genes have been taken from a soil bacterium (Bt or Bacillus thuringiensis) and put into the DNA of corn and potatoes and a fish gene was spliced into the DNA of a tomato (this product was not commercialized). Genetic engineering can therefore introduce genes into food crops that have never before been a part of the human diet. This is something that we have not been able to do before and it cannot be achieved through traditional plant breeding.
Foreign genes are inserted directly into host organisms with a “gene gun” which shoots DNA into the cells of another organism, or genes are transferred using vectors, like viruses, to carry genes across. The genes are not transferred alone but are actually part of a package of genes that include “marker genes”, often antibiotic resistant genes, to check that the transfer was successful, and “promoter genes”, often viral genes, to maker sure that the new genes become active.
Debate Over the Science
There is serious dispute over the science of genetic engineering itself. There is an ongoing ideological and scientific debate between those who argue that genetic engineering is a precise science that is simply an extension of traditional plant breeding, and those who argue that the technology is entirely new and inherently risky or presently immature. [iv] This dispute is central to discussions about potential health risks since concerns originate in challenges to the methods and results of genetic engineering. Critical scientists argue that genetic engineering is based on false assumptions about the way organisms and their genes function. For example, Barry Commoner argues that the “central dogma” of GE - that an organism’s genes fully account for inherited traits – has been disproved, and Dr. Mae Wan Ho argues that basic premises are wrong, including the idea that each gene codes for one trait and that genes are stable and cannot be changed directly in response to the environment. [v] In this view, the complexity of organisms and the method of GE can result in unpredictable consequences including “secondary effects” whereby the interruption of new genes can change other functions in an organism and “gene silencing” whereby some genes that were previously active will stop.
The complex and unpredictable consequences of genetic engineering pose new challenges for risk assessment. The Royal Society of Canada Panel on the Future of Food Biotechnology (RSC Panel), commissioned by the Canadian government, argued that we may not be able to identify hazards if they result from secondary responses and that this first step in risk assessment would therefore fail. [vi] This is a major concern: How can we identify the health hazards of GE foods when we might not know what to look for?
Dr. David Suzuki articulated his concerns about the science of GE in the following way:
We are performing a massive experiment. The results will only be known after millions of people have been exposed to (these foods) for decades…Any politician or scientist who tells you these products are safe is either very stupid or lying. The hazards of these foods are uncertain. In view of our enormous ignorance, the premature application of biotechnology is downright dangerous. [vii]
Specific Child Health Concerns
Genetic engineering may only result in slight adverse reactions, if any, or in small changes to food nutrition, but even these may have a significant impact on the health of infants and children, especially when foods such as infant formula are the only foods being eaten, at critical stages in development. Any potential risks of consuming GE foods are magnified for children because of their immature immune systems and guts, with sick children being at particular risk.
Infants who are not breast-fed and cannot consume cow milk-based infant formula are given soy-based formula as their sole source of nutrition for the first six months of their lives. There are concerns that changes in the nutrition of infant formula could lead to undernourishment or affect infant bowel function [viii] but there are no studies that investigate these questions. The RSC Panel could not find data to support Health Canada’s judgment that GE foods are nutritionally the same as their conventionally produced counterparts. (p.82) Infants may be on a diet of soy-based infant formula because of health problems including gastrointestinal problems, putting them at even greater risk. [Some baby food manufacturers have eliminated the use of GE food ingredients and there is at least one infant formula on the market that is made with organic soy (not GE by definition). [ix]] The consumption of GE food by pregnant women, women who may becoming pregnant and breastfeeding mothers may also have implications for the development of allergies as well as growth and development but has not been studied either.
Just as GE soy has a particular impact on infants, other future products may have a specific or disproportionate impact. For example, Monsanto has applied to Health Canada for approval of GE (herbicide-resistant) wheat which, if approved, would be the first GE food to be consumed as a staple, in minimally processed form. [x]
There are hardly any studies on human health effects. In a widely publicized and debated experiment, Arpad Pusztai of the government-funded Rowett Institute in Scotland, found that rats fed GE potatoes (potatoes engineered to be insect resistant using the snowdrop plant in a type of crop not yet commercialized) suffered a number of serious health problems. [xi] This preliminary study raises questions about the impact of the food on gut structure and metabolism since the results showed a reduction in the weight of rat’s organs, depressed immune system response and evidence of intestinal inflammation and infection. Pusztai found that the amounts of proteins, sugars and starches in the potatoes varied from non-GE as much as 20%. The results of the study are still controversial but the test has not yet been repeated, followed up or contradicted [xii]
Introducing new genes into the human diet or moving genes to new contexts, could create new allergens. Allergic reactions can cause discomfort or lead to life-threatening anaphylactic shock, and delayed allergies or sensitivities can cause chronic conditions such as eczema, fatigue and migraines. Children are particularly sensitive, with allergy rates declining with age. Even proteins that are normally part of the human diet may, when introduced too early, lead to auto-immune and hypersensitivity or allergic reactions later. [xiii] The RSC Panel noted that, “The potential widespread use of GM food products as food additives and staple foods, including use in baby foods, may lead to earlier introduction of novel proteins to susceptible infants either directly or via the presence of the maternally ingested proteins in breast milk,” and result therefore in greater potential to develop allergies. (p.59)
There are no verified cases of allergic reactions caused by the genetically engineered foods currently on the market and the RSC Panel states that they do not appear to have any significant allergenic potential. The potential for health risks will rise, however, as more and different types of GE foods are commercialized and our dietary intake increases.
In a well-known case, the corporation Pioneer Hi-Bred transferred a Brazil nut gene into soya to enrich its nutritional value, but the new GE soybean was found to be highly allergenic to people with nut allergies. [xiv] The soybean was not commercialized and the case if often cited as proof that the assessment system works and that allergens in GE foods can be identified before they reach the market. Identification of the allergen in this particular case was, however, relatively simple since the nut allergen was well known. Despite this, the nut transgene was used in three other crops, none of which were commercialized, before the problem was identified. [xv]
There is no universal, reliable test for allergenic potential. [xvi] It is hard to assess allergenicity in every day life conditions especially when testing proteins that have no history in our diets, have an unknown allergenicity, or could create a new allergen or increase the expression of a minor allergen. [xvii] It will be hard to trace such allergies.
Another potential health hazard may be created with the use of viruses as vectors and promoters. One outcome of Arpad Pusztai’s study is speculation on the possible role of the cauliflower mosaic virus (CaMV) (closely related to the human hepatitis B virus) in the health problems observed. [xviii] The study’s co-publisher, Stanley Ewan, has recently warned that CaMV could increase the risk of stomach and colon cancers if people are eating GE whole foods raw. [xix] The Royal Society in the U.K. has concluded however that the risks of specific viral DNA sequences are “negligible”. [xx] Dr Mae Wan Ho disagrees and argues that introducing them could produce new viruses. [xxi] Ho argues that viruses or viral genes associated with diseases have the potential to recombine with the genetic material of other viruses and create new infectious viruses that can cross to different species through horizontal gene transfer. [xxii]
There are also concerns that the use of antibiotic resistance marker genes could result in the spread of antibiotic resistance - immunity to antibiotics used to treat diseases – hindering the treatment of diseases in children. This arises as a concern because genes may be transferred to non-GE plants and progress through the food chain and because DNA may survive in the gut. [xxiii] Not all humans have the same stomach acidity and the same quantity of digestive enzymes, especially very young or ill people. The British Medical Association and the RSC Panel agree that antibiotic marker genes should not be used, especially as alternatives do exist. Health Canada has not however restricted the use of antibiotic market genes, leaving open the possibility that more GE foods containing the genes could be approved.
As yet, there are no genetically engineered animals on the food market. However, the US company A/F Protein, with research facilities in P.E.I., is genetically engineering salmon to grow faster (Pacific salmon engineered with a growth hormone from Atlantic salmon) and professors at the University of Guelph have developed the “EnviroPig” to produce less phosphorous in its feces.
Environmental and Food System Contamination
Once genetically engineered organisms are released into the environment, they cannot be controlled and they cannot be recalled. The unintended spread of GE plants is an environmental problem that also constitutes a threat to public health. For example, volunteer or unintended GE plants are contaminating farmer’s fields and the food supply.
Genetic pollution means that GE is a serious threat to organic agriculture and, therefore, to the future ability of parents to choose organic food for their children (organic food is grown without chemical fertilizer, pesticides or genetic engineering). Already Saskatchewan organic farmers are suing the biotech corporations Monsanto and Syngenta for contaminating field crops with GE canola such that they cannot now grow organic canola. [xxiv] More organic crops will be threatened as more GE crops are approved for release.
There have been a number of important instances of unintended contamination of the food supply and non-organic crops with GE plants. These cases warn of the potentially serious health implications of contamination, especially as some crops are now being engineered to produce pharmaceutical drugs and industrial chemicals. In 2001, StarLink, a GE corn that was approved in the U.S. for animal feed but not for human consumption (because of concerns about allergenic potential) contaminated the human food supply and forced the recall of food products across the U.S. (trace amounts are still being found in U.S. exports). [xxv] In November 2002, a pharmaceutical crop - a corn genetically engineered to contain a drug for treating diarrhoea in pigs - was found in U.S. supplies of soybeans destined for human consumption. This is only one of two known instances with this particular crop, a crop that has not been tested for effects on human health. [xxvi] Earlier in 2002 genetically engineered piglets (the “EnviroPig”) from the University of Guelph were accidentally turned into animal feed and fed to chickens and turkeys in Ontario. [xxvii] There have also been at least two instances of GE crops containing unexpected and unapproved DNA. [xxviii] Any of these types of accidents could have fatal impacts. A U.S. based company is now inserting human cancer-causing genes into animals and plants to quickly develop mutant breeds and some scientists are concerned that this could result in the release of human cancer-causing genes into the environment. [xxix]
Risk - Benefit Analysis
Biotechnology corporations and the Canadian Government claim that GE crops and foods will bring many benefits including improved nutrition, decreased pesticide use and higher crop yields. These benefits are often used in risk-benefit analyses that conclude GE foods pose an “acceptable risk.” However, many promised benefits of GE have yet to be seen. Additionally, in applying the precautionary principle, benefits need to be examined in relation to what safer alternative solutions might exist.
Corporations argue that genetically engineered crops will reduce the use of harmful pesticides. The development of insect-resistant crops, for example, eliminates the use of certain pesticides but it does this by incorporating the toxin into the plant itself, changing the form the pesticide takes rather than eliminating it. While this may cut the use of insecticides for target pests it can also encourage insect resistance that would then force the creation of new pesticide products. In addition, 77% of the GE crops planted across the globe in 2001 were engineered to be herbicide-resistant (HR) meaning that they can survive sprayings of particular brand-name chemicals. This means that the majority of GE crops currently grown are actually tied to the use of chemical pesticides. The industry argues that HR crops can be sprayed less frequently, with one pesticide that replaces many older, more toxic chemicals. The evidence so far suggests however that the frequency and intensity of pesticide sprayings may be more than was projected and, in addition, the tendency for HR crops to persist as volunteers has led many farmers to use more toxic herbicides to get them off their land. [xxx]
Biotechnology corporations promise to develop higher yielding and drought resistant crops that will feed hungry children living in the Third World, as well as crops designed to carry important vaccines or vital nutrients. “Golden Rice”, for example, is promised as a solution to blindness in children caused by Vitamin A deficiency. Development agencies like Oxfam have, however, criticized this type of technological fix to problems of hunger and malnutrition that they see as primarily social and political problems. Golden Rice has also been criticized as ineffectual: an adult would have to eat 9kg of cooked rice a day to satisfy the required intake, and a pregnant woman would need twice that. [xxxi]
Golden Rice is an example of a so-called “functional food” which is part of the next generation of genetically engineered foods that promise direct health benefits for consumers. Other examples include the idea of a banana that could carry a vaccine or vegetables with new traits to fight cancer. Such foods could however be the source of even greater health risks and would certainly create new challenges for regulatory agencies that would need to substantiate product health claims as well as regulate for safety.
Testing and Government Regulation
The use of GE soy in infant formula and the potential coupling of GE soy and GE wheat in children’s diets demands study but this type of testing is not currently a requirement in Health Canada’s safety review. Unless there is evidence pointing to a potential health concern with a particular food, there is no trigger for this type of investigation. The U.K. Royal Society argues that, “Products that are designed to be consumed as a single food over extended periods of time by those who are especially vulnerable should be investigated more rigorously. These include infant formulas and follow-up foods,” and they recommend that “vulnerable groups such as infants need special guidelines” in nutritional assessments of GE foods. [xxxii]
Health Canada states in its Guidelines for the Safety Assessment of Novel Foods that it will estimate dietary exposure and consider population subgroups, and that this will then play a role in determining the extent of the toxicological and nutritional data they will request. However, Health Canada uses the controversial concept “substantial equivalence” that compares the GE food to its conventional counterpart and can allow approval without substantial safety testing. [xxxiii] The RSC Panel found that “regulatory requirements related to toxicological assessment of GM food appeared to be ad hoc and provided little guidance either as to when specific studies would be required or what types of studies would be most informative” (p.48)
A major consideration here is that Health Canada does not do its own safety testing but relies instead on data developed and owned by corporations. These data are corporate property and, as such, neither the public nor independent scientists have access to it. For this reason, we cannot assume that any tests for effects on child health have been done or that infant and child health has even been considered. For example, in 1999 Health Canada was ready to approve milk produced with the GE drug Bovine Growth Hormone regardless of high child consumption. [xxxiv] Health Canada’s summaries of their regulatory decisions so far suggest that no laboratory or feeding trial measurements of toxicity were conducted and there is no testing for long term exposures to examine chronic consumption of GE foods. [xxxv]
The Royal Society in the UK recommends post-market studies or surveillance as part of the overall safety strategy for allergies, especially for high-risk groups such as infants. [xxxvi] The RSC Panel agrees that, “it would be prudent to monitor for any unanticipated allergic effects following introduction of a GM food where the transgenic protein is novel to the human diet.”(p.61) However, such monitoring may not be feasible or effective, and it is no substitute for rigorous safety testing and regulation. Post-market surveillance would only uncover a health problem after the fact, and such a project can only accommodate specific hypotheses that need to be determined before hand, meaning that once again, unexpected outcomes may not be found. [xxxvii]
There is no way to trace GE foods since there is no mandatory labelling in Canada. The British Medical Association and the RSC Panel agree that labelling is needed to track potential health effects and allow for individual monitoring of GE food intake; the RSC Panel argued that, “lack of labelling can lead to delayed recognition of the emergence of an allergy, with consequent under-reporting.” (p.71) Without mandatory labelling of all GE foods and food ingredients, the only options open to parents who want to avoid any potential risks to their children, are to buy organic foods and avoid non-organic soy, corn and canola derivatives.
Conclusion
Genetic engineering poses new risks to the health of infants and children. As such, it requires specific and rigorous regulation, including extensive, independent study and democratic debate. Many groups, including the Canadian Organic Growers, Sierra Club of Canada, the Canadian Association of Physicians for the Environment, and the Council of Canadians are calling for public hearings on the future of genetic engineering. They, and the RSC Panel, are calling for an overhaul of the regulatory system and recommending that Canada adopt the precautionary principle in relation to GE. The precautionary principle advises us to take action to anticipate and prevent harm even when we do not have conclusive evidence about causes. The principle recognizes that science cannot be isolated from political and ethical issues and acknowledges the limitations of scientific study. It demands that the following questions be answered: Is genetic engineering necessary? Are there safer alternatives?
[i] Submission to the Health and Community Care Committee on the Health Impact of GM Crop Trials, Scottish Parliament, p.1.
[ii] For example see Jose L. Domingo, “Health Risks of GM Foods: Many Opinions but Few Data,” Science, Volume 288, June 9, 2000.
[iii] Some GE cottonseed oil is imported from the U.S. For a list of all crops approved in Canada and details of where they are the food system see “Regulating Genetic Engineering for Profit,” Lucy Sharratt, Polaris Institute, 2002, www.polarisinstitute.org
[iv] See Ann Clark, University of Guelph, “What is Sound Science?” 2000, www.plant.uoguelph.ca/research/homepages/eclark/ for a list of scientists in various disciplines who are critical of GE. See also the Third World Network www.twnside.org.sg for a list of scientists who have signed the World Scientists Statement.
[v] Barry Commoner, “Unravelling the DNA Myth: The Spurious Foundation of Genetic Engineering,” Harpers, February 2002, and Mae Wan Ho, Genetic Engineering: Dream or Nightmare?, Second edition, 2000.
[vi] See the Panel report “Elements of Precaution”, February 2001, www.rsc.ca, p.47.
[vii] “Suzuki Issues Warning,” The Globe and Mail, October 20, 1999.
[viii] Robert Uhlig, “Fears for babies from GM milk” The Daily Telegraph, February 5, 2002.
[ix] For a list of GE-free brands of infant formula and other foods see Greenpeace “Survey of Infant Formula and Baby Foods”, October 29, 2002 as well as the Greenpeace Shoppers Guide www.greenpeace.ca/shoppersguide. Companies that have removed ingredients from baby food products include Earth’s Best, Milupa, Healthy Times and Tiny Bites; as well, Heinz has committed to phasing out GE ingredients.
[x] Rod MacRae et al., “Against the Grain”, Greenpeace Canada, November 2002.
[xi] See Stanley W.B. Ewen and Arpad Pusztai, “Effects of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine,” The Lancet, Volume 354, October 16, 1999.
[xii] Pusztai was fired from the Rowett Institute after appearing on British television to discuss his results and there was a public campaign launched to discredit him.
[xiii] Dr. Martha Herbert, “Genetically Altered Foods: We are Being Exposed to One of the Largest Uncontrolled Experiments in History,” Chicago Tribune, September 3, 2000.
[xiv] Initial evaluation using a mouse model did not detect the problem. RSC Panel, p.55.
[xv] Royal Society of Canada, Panel on the Future of Food Biotechnology, “Elements of Precaution”, February 2001, p.55
[xvi] Andre H. Penninks, “Topic 8: Animal Model for Allergenicity Assessment”, Joint FAO/WHO Expert Consultation on Foods Derived from Biotechnology, Biotech 01/10, January 2001
[xvii] Arpad Pusztai, “Genetically Modified Foods: Are They a Risk to Human/Animal Health?,” June 2001 www.actionbiosceince.org/biotech/pusztai.html#Primer; Steve L. Taylor, “Topic 1: Overview of the Current Approach to Determine the Allergenicity of Genetically Modified Foods (Decision Tree Approach)”, Joint FAO/WHO Expert Consultation on Foods Derived from Biotechnology, Biotech 01/03, January 2001.
[xviii] “Why I Cannot Remain Silent” in GM FREE Volume1, Number 3, August/September 1999.
[xix] “GM expert warns of cancer risk from crops” The Sunday Herald, 8 December 2002, Rob Edwards.
[xx] U.K. Royal Society, “Genetically modified plants for food use and human health – an update”, February 2002, p.3.
[xxi] Mae Wan Ho, Genetic Engineering: Dream or Nightmare?, Second edition, 2000.
[xxii] Mae Wan Ho, “Horizontal Gene Transfer – The Hidden Hazards of Genetic Engineering,” Institute of Science in Society, www.i-sis.org.uk/horizontal.php
[xxiii] Royal Society of Canada, Panel on the Future of Food Biotechnology, “Elements of Precaution”, February 2001, p.9; John Vidal, “GM genes found in human gut” The Guardian, July 17, 2002; Mae Wan Ho, Genetic Engineering: Dream or Nightmare?, Second edition, 2000. p.163; Arpad Pusztai, “Genetically Modified Foods: Are They a Risk to Human/Animal Health?,” June 2001 www.actionbiosceince.org/biotech/pusztai.html#Primer;
[xxiv] See www.saskorganic.com for details.
[xxv] “Japan find StarLink in US corn cargo”, Randy Fabi, Reuters, December 27, 2002.
[xxvi] “Corn for Growing Far Afield?” Justin Gillis, The Washington Post, November 16, 2002.
[xxvii] “Accident Raises GMO-research flag” Stephen Struass, The Globe and Mail, February 19, 2002.
[xxviii] Andrew Pollack, “Mysterious DNA is Discovered In Soybeans by Scientists”, The New York Times, August 16, 2001. Health Canada reviewed the safety of the unapproved DNA once it was discovered and concluded there was no risk:
http://www.hc-sc.gc.ca/food-aliment/mh-dm/ofb-bba/nfi-ani/e_glyphosate_soybean.html
[xxix] Antony Barnett and Robin McKie “Scientists condemn new gene technique”, The Observer, U.K, November 24, 2002
[xxx] Soil Association, Seeds of Doubt, UK, September 2002.
[xxxi] Paul Brown, “GM rice promoters ‘have gone too far”, The Guardian, Saturday February 10, 2001.
[xxxii] U.K. Royal Society, “Genetically modified plants for food use and human health – an update”, February 2002, p.7 and p.3.
[xxxiii] Erik Millstone, Eric Brunner and Sue Mayer, “Beyond Substantial Equivalence” Nature, October 7, 1999; Royal Society of Canada, Panel on the Future of Food Biotechnology, “Elements of Precaution”, February 2001, www.rsc.ca,.
[xxxiv] Lucy Sharratt, “No to Bovine Growth Hormone: Ten Years of Resistance in Canada” in Redesigning Life? edited by Brian Tokar, 2001, pp.385-396.
[xxxv] Ann Clark, University of Guelph, “Food Safety of GM Crops in Canada: toxicity and allergenicity,” www.plant.uoguelph.ca/research/homepages/eclark/
[xxxvi] U.K. Royal Society, “Genetically modified plants for food use and human health – an update”, February 2002 cited in Greenpeace, “Special Health Risks of GE Food for Infants, Babies and Children.” October 2002.
[xxxvii] Lucy Sharratt, Notes from the International Conference on Post-Market Surveillance of Genetically Modified Foods, Health Canada, Ottawa, October 2002.