OPINION: GMOs -- A Balanced View
History of Gene Manipulation
“Genetically Modified Organisms” is an area that abounds with skepticism, suspicion and fear. The mere mention of genetic modification is enough to give a substantial portion of the population the ‘heebie jeebies”. They have been a source of controversy since the biotechnology was introduced in the 1970s. Decried as unnatural, the manipulation of genes is seen as inherently threatening and dangerous.
Science explains that in sexual production in plants and animals, parents supply two gametes (male and female) that fuse and reproduce into young. Thousands upon thousands of genes are randomly mixed during fusion to produce an offspring that is half of each parent. This randomization explains why we and our siblings never look exactly like either of our parents. It also explains why each apple, carrot or turnip is different from its counterpart and its parent.
Genetically manipulated organisms, the precursors to Genetically modified organisms, have been with us for millennia. Humankind began manipulating genes thousands of years ago. Seeds from plants with desirable traits were collected and grown. Repeated over generations a very different plant resulted. A leafy kale like plant, selectively bred, cross pollinated and cultivated over thousands of years resulted in the broccoli, cauliflower, Brussels Sprouts and the horseradish we consume today. These can all be traced back to a common ancestor. Maize, similar to the ‘baby corn’ in oriental food, was similarly manipulated to produce the big, sweet cobs of corn consumed today.
Both food and service animals have undergone the same process. Large, fast growing, healthy bulls have been bred with cows of the same description to produce offspring of greater size and health. Such ‘animal husbandry’ has resulted in huge changes in poultry, pork, sheep and more over the centuries. Domesticated non-food animals have been similarly bred for specific genetic traits. Comparison of a long-legged thoroughbred to the massive draught horse is an example. A St. Bernard compared to a Chihuahua is another.
Mutation Breeding has been used since the 1930s . This process involves the process of exposing seeds to radiation or chemicals to induce mutation. Mutants with desirable traits are then bred with other cultivars. Cultivars are plants that are selected for one or more specific traits. To date more than one thousand mutant varietals of major staple crops are being grown worldwide. New varieties of rice, wheat, barley, pears, peas, cotton, peppermint, sunflowers, peanuts, grapefruit, sesame, bananas, cassava and sorghum have been grown using this method.
It is with Mutation Breeding that the controversy begins. A number of food and seed companies offer organic products developed from this method. Products include mutagenic barley and wheat ingredients used for organic beers. Mutagenic varieties of grapefruits are also sold directly to consumers as organic. Several companies that support outright bans or strict labelling of GMO crops market their own products without reference to the mutagenic source of their own goods.
Genetically Modified Organisms
A GMO or Genetically Modified Organism, as legally defined in the Cartegana Protocol on Biosafety (which regulates international trade in living GMOs), is “any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology”.
A naturally occurring bio technical engineer that skips husbandry and uses genetic modification directly is the bacterium Agrobacterium tumefaciens. This organism infects a plant and injects part of its own DNA into the host’s cells to create a tumour that feeds the bacterium. This ability has not been lost on human bioengineers who remove the DNA that the bacteria wants to deliver and replaces it with the gene being studied. It produces a far more predictable result than other genetic recombination.
Laboratory created GMOS can be broken down into three subcategories. Transgenic Organisms whose genetic makeup has been altered with material from other unrelated organisms is one. This area has given rise to organisms such as fish that glow in the dark due to the addition of jellyfish genes that cause fluorescence. Bio-steel is the product of another transgenic organism, goats that have had a spider gene inserted and extrude the silk-like protein as a component of their milk. A group of food crops, specifically soybean, sugar beet, canola and corn, grown in Canada are transgenically modified with bacterial genes to resist particular pesticides. Bt corn and other Bt food-plants have been designed to contain insect toxins derived from a spliced gene from the bacterium Bacillus thuringiensis.
The transgenic method is used to create insulin. The primary producer is the Escherichia coli bacterium which produces insulin when a synthetic human gene is introduced into the cell. In medical research the transgenic method has led to medications that produce clotting factors for treatment of haemophilia and human growth hormone that is applicable in some forms of dwarfism. A myriad of other applications are being researched to create solutions for cystic fibrosis, sickle cell anemia, Parkinson’s disease and muscular dystrophy. The environment has also seen the benefits of genetically modified bacteria that clean up mercury pollution, detect arsenic in drinking water and are able to leach copper from ore.
The second group are Cisgenic, GMOs whose genetic makeup has been altered with the addition of material from the same or closely related organisms. Example are plants engineered to be more drought tolerant, disease resistant or have higher production values with material spliced in from other plants. The introduction of the apple scab resistance gene from wild to cultivated apples is one example. Another involves building resistance to phytophthora infestans in potatoes, the principle cause of the great Irish potato famine in the mid 1800s. Here resistant genes from wild species are introduced into susceptible elite potato varieties.
Subgenic GMOs are the third group. The non browning ’Arctic Apple’ would fall into this group. Here certain genes are suppressed or eliminated entirely. The trademarked apple, developed in Canada, has been engineered through the suppression of the gene that causes browning, rather than the addition of material. Chinese researcher Gao Caixia filed patents on the creation of a strain of wheat that is resistant to powdery mildew in 2014. Here three sets of genes were eliminated to create the desired trait.
Safety of GMO Foods
There is no scholarly evidence at this point that GMO foods are dangerous to our health just because they are genetically modified. Genetic material exchange in normal growth and cultivation is far greater than that involved in suppression or addition of a gene of similar species.
GMO foods have not been identified as a human health concern by the World Health Organization and Food and Agricultural Organization of the United Nations. No blanket endorsement has been offered, but rather a case by case protocol has been suggested. The OECD (Organization for Economic Co-operation and Development) states that no evidence of adverse effects on human health resulting from consumption of GMO foods have been reported in peer reviewed scientific literature.
GMO foods have been deemed to be safe by Health Canada which follows the protocol for safety testing suggested by the three international organizations mentioned above. Confidence in the safety of GMO foods has been supported by a range of respected popular scientific journals and a myriad of independent researchers. One site offers more than 600 research papers that examine the safety of GMO foods and feed.
Despite a wealth of scientific evidence that GMO foods are, of themselves, safe, media has focused more on detractors. One such example is Jeffery Smith, an American consumer activist and self-published author. He has authored of two books, Seeds of Deception: Exposing Industry and Government Lies about the Safety of the Genetically Engineered Foods You’re Eating, and Genetic Roulette. The information offered in the latter was dismantled with peer reviewed scientific research. There are a myriad of other anti-GMO organizations and individuals focused on labeling and/or banning GMO foods.
Research points overwhelmingly to the safe nature of GMO foods, by published safety assessments on GMO foods and feeds.
Escape of GMOs into the Wild
One major concern is the possibility of a GMO to escape, potentially introducing the engineered genes into wild populations. A fictional analogy might be a domestic pig transgenically modified to produce a much tougher skin for leather goods. If the animals escaped and became feral such animals might become impervious to normal hunting and other management techniques, the tougher skin being more impervious to bullets. Given the danger and damage unmodified feral pigs are presently creating, such a scenario becomes frightening.
In plant GMOs such a scenario has already occurred. Ecologist Cynthia Sagers and her team found two varieties of transgenic canola in the wild in North Dakota — “one modified to be resistant to Monsanto’s Roundup herbicide (glyphosate), and one resistant to Bayer Crop Science’s Liberty herbicide (glufosinate).” They also found some plants that were resistant to both herbicides, showing that the different GM plants had bred to produce a plant with a new trait that did not exist anywhere else. The discovery of these plants and their resistance to two commercial herbicides indicates that these feral populations of canola have been part of the landscape for several generations. Whether these escaped GM canola plants have any ecological consequences will not be known until further study. Those plants that have evolved resistance to both herbicides have the potential to become a weed problem for farmers in the future. The findings were presented at the Ecological Society of America meeting in Pittsburgh. Sagers also cautioned that the results might be skewed because all the plants came from ditches and roadsides where canola seed might readily be hauled.
Some people have claimed that GMOs have created ‘superweeds’. A more accurate explanation would be that regular application of the herbicide and failure to rotate crops has produced a situation where generation after generation containing a natural resistance passing those genes along to their offspring and became tolerant to glyphosate. 249 plants worldwide have undergone the same process since 1996.
Concerns also arise with the possible escape of GMO animals, particularly fish, into the environment. Traits that include cold-water survival and fast growth are being sought. Researchers in Cuba and the UK have engineered tilapia to grow and put on weight up to 300% faster. An extraordinary 35 fold increase in growth rate was demonstrated with a Mud Loach in Korea. In North America an Atlantic salmon with a growth hormone from a Chinook salmon has been created by Aqua Bounty Technologies, Inc. This genetically modified fish grows 4 to 6 faster as a juvenile than it’s wild counterpart. In the United States, escape into the wild is limited by the FDA, allowing the fish to be grown only in land-locked containers and by growing stock that is sterile and incapable of reproducing in the wild.
The threats are nicely encapsulated in a statement drawn from an article from the US National Library of Medicine. “If GM fish escaped from fish farms, they could further upset the oceans’ delicate ecology, causing ecological disruption or species extinction. Transgenes that increase cold-, salt- or heat-tolerance could allow GM fish to expand into new territories. GM fish with higher disease resistance and better use of nutrients could outcompete wild relatives and change predator–prey relationships, and they could therefore occupy new ecological niches where wild species would usually not survive. Finally, by mating with wild fish, escaped GM fish could spread the transgene among the wild population, which could cause conflicting effects on mating success, viability in natural habitats and other fitness factors required for the species to survive.”
On a more positive note, genetic modification in fish is being researched in an effort to control the spread of invasive carp. A genetic modification called ‘Daughterless Carp’ involves blocking the genes involved in embryos developing into females. The result is that all offspring being male. This skews the sex ratio in the carp population and limits its growth. Another method is identified as ‘Trojan Gene’ where reproductive success is increased while simultaneously decreasing the viability of the offspring.
Non-Target Species and Environmental Concerns
A second environmental concern is voiced around the susceptibility of non-target organisms (e.g. insects which are not pests) to the gene product. One example is Monarch caterpillar – “The Monarch butterfly has generated the most detailed research into the impacts of GMOs on wild species.” Studies point to pollen from BT corn, a transgenic devised to resist the European Corn Borer, that is toxic to Monarch Butterfly larvae. Milkweed, the exclusive food of monarch caterpillars, is commonly found around cornfields. When pollen from Bt corn is dispersed by the wind and lands on Milkweed the larvae is poisoned. Other studies support these findings.
In other cases an increase in pest species populations correlated very closely with the planting of Bt Cotton. Mirid bug populations rose to pest status in association with a regional increase in Bt cotton adoption. Analyses show that Bt cotton has become a source of mirid bugs and that their population increases are related to drops in insecticide use on the crop.
Genetically altered potatoes effected microbial life in the soil. Feeding response in nematodes was significantly affected and protozoan populations were greatly reduced. Two types of aphids feeding on GM wheat showed rapid adaptation in 3 generations while others were not affected by the built in resistance at all. Bacterial populations declined in soils where transgenic Bt rice was cultivated. Larval growth rate and mortality of Green Lacewings were negatively impacted by toxins engineered into Bt transgenic plants.
The possibility that Bt plants have indirect impact on populations of species that depend on the pests or survival or reproductionis being studied. The spraying of crops adds to the decline of farmland birds dependant on weed or pest species for food.
Unintended effects of GMOs on non-target species have and will continue to take place. Some have been subject to study but there exist more susceptible organisms than have yet to be identified.
GMOS and Glyphosate/Bt Toxin Concerns
One area of concern about GMOs is the herbicide glyphosate that is sprayed on growing plants. Four glyphosate resistant crops are grown in Canada: canola, corn, soy and sugar beet. The transgenic modification involves the splicing of bacterium genes into the crop plant to make it resistant to glyphosate. It is a post emergent herbicide applied after the crop has started to grow, when required during growth and again before harvest.
Approximately 95% of canola crops are genetically modified. Sugar beet GMO percentage is 100% while grain corn and soybeans come in at 80% and 60% respectively.
Glyphosate formulations are the most highly used herbicides on the planet today. Worldwide, around 650,000 tonnes of glyphosate products were used in 2011 and sales were worth around US$6.5 billion in 2010.
Glyphosate binds to metal atoms and ions. It was invented in 1960 for use as an industrial descaling agent and was patented in 1964. It was quickly observed that glyphosate killed all plants. Monsanto bought the rights to the molecule and re-patented it as a herbicide. Glyphosate binds to the atom of metal in a living plant cells and inactivates EPSP synthase by binding to it. By 1996 Roundup Ready, soy and corn had been created. In 2010 Glyphosate was patented as an antibiotic. One ppm was toxic enough to kill a broad range of bacteria with the exception of Salmonella and Botulism.
Glyphosate has been recently listed as a probable carcinogen in the 2A category by International Agency for Research on Cancer. The 2A list also includes many compounds used in cancer treatment, anabolic steroids, ultra-violet radiation (such as black light or excessive sunlight) and several pesticides.
Increased glyphosate use is directly related to the number of acres converted to growing GMO crops. As GMO acreage increases so does the application of the herbicide. However, comparing the toxicity of glyphosate to that of the biocides previously used indicates that, over all, the environment has become less dangerous. The US Geological Survey reports that the use of the following chemicals has dropped significantly: Nicosulfuron, Metribuzin, Fluazifop, Cyanazine and AlaChlor.
The second area of concern is with Bt transgenic plants that include corn, cotton and potatoes. Here genes from the Bacillus thuringiensis bacterium are spliced into the cultivar to produce a Bt pesticide during growth. The bacterium is pervasive throughout the plant. During sporification many Bt strains produce endotoxins that have insecticidal action.
Because of its specificity to insects it has been used to control pests since the 1920s. These pesticides are regarded as environmentally friendly, with little or no effect on humans, wildlife, pollinators, and most other beneficial insects, and are used in organic farming. Bt products were found to be safe for use in the environment and with mammals. The Environmental Protection Agency has not yet discovered any human health hazards related to their use. It was found that Bt was safe enough to exempt it from food residue tolerances, groundwater restrictions, endangered species labeling and special review requirements.
Genetic engineering is neither the progenitor of Frankenfood that ardent anti-GMO groups promote, nor the worry free cornucopia that biotech corporations would have us believe. It falls into the same category as nuclear energy. Nuclear Physics, applied properly, can shrink tumours and produce electricity as well as weaponry capable of ending all life. Both sciences bear close watching. Education, transparency, good science and legislation are required to control and regulate a technology that has tremendous potential for good or for harm. Neither a Luddite mentality bent on dismantling it nor the blind following of glowing promises is acceptable here.
Critical thinking and careful examination of all aspects of genetic engineering is absolutely essential. That can only occur if anti-GMOs and biotechs lay out the complete truth. Science facts are not arguable … blanket statements and manipulation by both sides are. Intentional misinformation about GMO or manipulating research for profit is simply wrong. Only when ethical work is assured can we as consumers decide for ourselves the risks involved and whether or not we are willing to take them. Until that point arrives an amended adage from the X Files is appropriate here: “The truth is out there … but today you have to dig for it.”