Prof. Joe Cummins and Dr. Mae-Wan Ho
What main classes of traits or combinations of traits produced through modern biotechnology are likely to be commercialized within the next five years?
The main emphasis of traits for commercialization will be on genetically modified crops altered to produce pharmaceutical products such as vaccines, cytokines and many other products used to prevent or treat disease. Such products will enter the main food chain as pollutants from pollen and other means of escape and careless management. In many cases the products will serve as potent threats to the food supply [1, 2]. In crop development the main emphasis will be on endogenous production of toxins to control fungal and bacterial diseases along with introduction of cassettes containing multiple versions of insect resistance genes or herbicide tolerance genes to cope with resistant pests emerging from extensive use of resistance genes [3].
There will also be 'male sterile' and other 'terminator crops' coming on the market in the guise of preventing gene flow [4, 5]. Another related development to prevent gene flow is the incorporation of transgenes into chloroplasts [6]. But none of them will be effective for the purpose, and involve other risks that have not been adequately assessed.
What new classes of traits or combinations of traits for food produced from modern biotechnology are in the pipeline of research and development?
A great deal of pressure is beginning to develop to test and release genetically modified food animals. The first food animal to be tested and released is likely to be a rapidly growing salmon and other transgenic fish [7]. That approval will rapidly be followed by release of milk cattle modified with human lactoferrin and pigs modified to release reduced phosphorous in manure.
In field crops, effort will be made to manipulate quantitative trait loci (QTL). These are the most significant genetic modifications that can be made because those genes are native to the crop and govern the most important traits such as yield of the crop, disease resistance and resistance to stress such as water shortage, heat, cold or soil nutrient utilization [8].
Also mooted are nutraceuticals, plants engineered to enhance health through, for example, increase in cancer-prevention metabolites.
Genetically modified bacteria have been proposed as probiotic food supplements [9].
Which new methods of production or design of organisms developed through modern biotechnology can be envisaged?
The most important development we would like to see for the further development of crop genetic engineering would be methods for homologous recombination that would allow targeted and precise gene replacement. Currently ' crop genetic engineering is based solely on illegitimate recombination and this has created fundamental problems with genetic stability. Some developments have been made using site-specific recombination especially the bacterial cre-lox system [10]. But that system is plagued by the problem associated with the introduction of the lox sites, which tend to create conditions leading to chromosome instability and genome scrambling [11].
The preferred development would be one employing homologous recombination [12], the complete success of which is currently limited to natural meiosis in crop plants. It has been proposed to convert C3 photosynthesis in most crop plants to C4 photosynthesis that does not entail photorespiration, thus more effectively reducing atmospheric carbon dioxide levels [13]. Poorly thought out general modifications of that type might control greenhouse warming, but could trigger an ice age in the worst case scenario. The main point is that new developments should be carefully evaluated beforehand.
Finally, the most desirable development in crop biotechnology would be genetic transformation systems that avoided the somaclonal variation associated with plant tissue culture and current transformation procedures. These procedures cause fundamental genetic instability that is passed on to the commercial crop, and enhance the danger of horizontal gene transfer and recombination [14, 15, 16].
What evidence it there linking the direct or indirect effects on human health and development to the use of modern biotechnology in the production of foods and food ingredients?
Evidence is especially requested in the fields of:
Food safety (including changes in constituents i.e. nutritional changes, changes in natural toxicants).
Regulatory bodies such as the Codex Alimentarius Commission and a number of nations are currently debating whether or not the concept "substantial equivalence" that is employed to regulate genetically modified crops in North America is appropriate for evaluating the safety of genetically modified crops. Substantial equivalence is simply an assumption that genetically modified crops are substantially equivalent in composition and hazard to crops that have not been genetically modified, and is totally unscientific. That is because the GMO or its individual constituents could effectively be compared, not to the parental line, but to any mixture of varieties of species, and the tests used are arbitrary and non-discriminating [17]. More seriously, there have not been safety tests carried out which reflects the uncontrollable, variable nature of the transgenic process, and the novel gene products, and combination of genes introduced into our crops, many of which used as food.
There are many examples of non-equivalence between the GMO and the parent line from which it was derived. For example, corn modified with a Bt accumulated a much higher lignin content [18], high lignin content is associated with lower digestibility of the product.
The assumption of substantial equivalence has been used to avoid extensive laboratory testing of the crops including animal feeding and clinical testing with human volunteers. Using the substantial equivalence assumption, the costs of extensive testing of the modified crops is avoided and the potential liability from untoward side effects is also avoided.
The substantial equivalence assumption benefits only the corporate producers of genetically modified crops and the concept should be scrapped because it discourages adequate investigation of the modified crops. The present climate has discouraged adequate investigation of the toxic effects of genetically modified crops.
For example, at least one peer reviewed publication, such as one showing damage to the ileum of animals fed potatoes modified with a gene for Bacillus thuringiensis (Bt) cry 1 toxin to control insect pests has been ignored by regulators [19]. No effort seems to have been made to follow up the important study. Recently, the US Environment Protection Agency has given the all clear to the re-registration of bt corn, with claims that the risks are negligible. This was contested by other scientists [20]. (Other evidence on the toxicity of bt to laboratory and wild animals is reviewed in a paper, "Environmental and health impacts of Bt" by Lim Li Ching, included as appendix 1.)
Similarly, a peer reviewed study showing injury to animals fed potatoes modified with a gene for a plant lectin [21]. The study was violently criticized by proponents of genetically modified crops but no effort was made to fund and initiate the studies needed to establish the chronic and acute toxicity of the modified crop.
There are many other studies suggesting that transgene products themselves may be harmful, though no feeding studies using the transgenic plants have been carried out.
Epidemiological data such as that showing increase in soya-related allergy associated with increase in GM soya import in the UK [22], and sharp increases in foodborne disease in the US since the introduction of GM food in 1994 [23], have simply been ignored.
One general source of toxicity may be that bacteria and their viruses have a high frequency of the CpG dinucleotide in their DNA. These CpG motifs are immunogenic and can cause inflammation [24, 25], septic arthritis [26] and promotion of B cell lymphoma [27].
Apart from hazards due to introduced genes and gene products, the random nature of the transformation process are well known to give rise to both unintended position effects and pleiotropic effects that will have large impacts on safety. Hence the importance of ascertaining that each transgenic line is genetically stable, by event-specific molecular data [28] before it is subjected to safety assessment.
Other ecological and health impacts arise from gene flow. Cross-pollination between herbicide tolerant transgenic varieties have already given rise to multi-herbicide tolerant volunteers in Canada and the United States [29. 30].
Genes can transfer also horizontally to unrelated species. Here, there is a lot of selective citing of negative findings and explaining away of positive results. Worse, scientists presenting incriminating evidence and journalists who dare to draw attention to it are all subjected to attack and vilification. Horizontal gene transfer is reviewed separately in the paper, "Horizontal gene transfer - hidden hazards of genetic engineering", by Mae-Wan Ho in Appendix 2.
Certain transgenic constructs containing recombination hotspots increase transgenic instability and may enhance horizontal gene transfer and recombination. The CaMV 35S promoter - found to have a recombination hotspot - is reviewed separately in the paper, "A brief history of the CaMV 35S promoter" by Mae-Wan Ho in appendix 3.
Are there established systems for post marketing surveillance/monitoring of products and how such procedures could be applied to foods derived from modern biotechnology;
There is at present no systematic post-market surveillance/monitoring done anywhere in the world. In order to so so, there must be clear labeling and traceability of genetically modified food products. In North America, labeling of genetically modified products was not required (in some states, effort was made to outlaw labels indicating that the products were not genetically modified). In addition, many transgenic crops have been de-regulated, so no one will know if they are transgenic or not. The policy allowing sale of unlabeled, unregulated genetically modified products was implemented even though surveys repeatedly showed most citizens demanded that modified food products be labeled.
Turning to the actual physical surveillance of genetically modified crops, that surveillance is achieved using a rapid polymerase chain reaction (PCR) procedure to amplify the cauliflower mosaic virus (CaMV) promoter and associated Nos terminator from the other end of the gene insert [31]. That procedure is adequate for most modified crops now marketed, but in some instances other promoters have been used in the commercial product and the United States and Canada allow information to be considered a trade secret, thus unavailable to the public. In such circumstances, it is almost impossible to monitor for GM consumption.
Certainly, the sequence of the promoter and the entire construct used in a commercial product should be made public to make it available for analysis. Rapid enzyme linked immunoassay (ELISA) techniques are available targeting proteins such as the Bacillus thuringiensis (Bt) toxins inserted into crops to kill insects. ELISA tests are nearly instantaneous, they are inexpensive and qualitative tests can be done by untrained people [32, 33]. The tests now available are adequate for most modified products but relatively simple genetic alterations can be used to avoid routine screening. For that reason full and truthful publication of all the commercial genetic modifications is essential in order to provide unique molecular identifiers for each produce. Combined product labeling, traceability and monitoring of the modified products is essential in determining the long term risks and benefits of modified products.
Environmental effects (including potential effects on health, impact on health resulting from changes in pesticide use, water and fuel usage, nature protection, sustainable agriculture or biodiversity and regional variation within).
More than 75% of the GM crops currently grow are tolerant to broad spectrum herbicides. The hazards of glyphosate (in Roundup Ready) are dealt with in a paper " included in appendix 4, and the hazards of glufosinate (Liberty Link) in appendix 5.
The most significant environmental impact of genetically modified crops has been the spread of genes from the modified crop to surrounding crops or to weeds (see last section). Within the past year, it became evident that the separation distance required for planting transgenic Canola had been greatly "underestimated", and that the patented gene for herbicide tolerance had spread so widely that there was virtually nowhere in western Canada that canola could be grown free of genetic pollution from the patented herbicide tolerance gene [34]. The catastrophic spread of modified genes from canola in western Canada has largely been overshadowed by the reported finding of the spread of modified corn genes to Mexican landraces [35]. That finding was not followed by an intensive effort to get to the bottom of the phenomenon but instead the process turned into an orgy of denial and obfuscation by corporate and academic proponents of genetic modification. The contamination of Mexican landraces is especially significant as Mexico is the centre of origin and biodiversity of maize. A large coalition of non-government organisation are demanding a ban on releasing GM crops in centres of origin and biodiversity.
The Mexican maize controversy highlights the importance of horizontal gene transfer and its environmental and health impacts that have not been subject to anywhere near sufficient investigation. The proposed male sterile and terminator crops for transgene containment will not prevent the spread of transgenes by horizontal gene transfer [4,5].
What evidence is there is there relating the effects on human health and development to:
The impact of modern biotechnology on food security issues sustainability and post harvest losses considering different regional situations?
The main emphasis of modern biotechnology has been the discouragement of seed saving to insure the extended profits of the seed producers (mainly large multinational chemical corporations). Many corporations have developed variations on the theme of the terminator technology that genetically prevents production of fertile seeds, only production of the crop for sale during one season. Seed saving is traditional in many societies worldwide and that has allowed for a kind of insurance against being cash poor during years of environmental stress. Furthermore, saved seeds tends to be repositories of genetic variability to protect against epidemics of pest losses in contrast to the genetic uniformity imposed by dependency on corporate seed producers.
These terminator crops are now being promoted, falsely, as a way of transgene containment. In fact, it can be shown that male-sterile genes are spread by such male-sterile crops.
The substantive issue of post-harvest losses have hardly been touched in genetic engineering other than in the early release of a tomato with a long shelf life. That product failed because its quality was poor. Currently, research is being pursued using genetic antisense technology to reduce the rate of fruit spoilage. There has been limited work using GM crops modified with Bt and these experiments showed some success in limiting insect damage in stored maize [36]. But there are already indications from a recent study in China that such crops can alter the pest populations through development of resistance and non-target pests so as to render the biopesticide effectively useless [37].
The most important ethical, legal and social issues all arise from the patenting of GM seeds under the Trade Intellectual Property Rights Agreements. This is dealt with in detail in the paper "Patents on life patently undermine food security" by Lim Li Ching in Appendix 6.
Article first published 09/09/09
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