Genetically Modified Foods | The Canadian Encyclopedia


Genetically Modified Foods

GM plants were first marketed in the 1990s. The first commercialized GM crop was a TOMATO called Flavr Savr (resistant to rotting), marketed in 1994 by a US-based company, Calgene. Since then, many GM crops have been commercialized.

Genetically Modified Foods

  Genetically modified (GM) foods are made from crops, animals or microorganisms whose GENETIC material has been altered to acquire specific traits using recombinant DNA technology. Recombinant DNA technology refers to combining genes from different organisms, sometimes across species. The resulting organism is said to be "genetically modified" or "transgenic." For this purpose, a gene conferring desirable traits is isolated from an organism (a BACTERIUM, a VIRUS, an ANIMAL or a PLANT) and introduced into a recipient plant or animal. Thus GM foods are foods produced from these GM crops or organisms. Current GM products are not limited to foods but include several beneficial products including medicines (eg, INSULIN), vaccines, animal feeds and fibres.

Genetically Modified Plants

GM plants were first marketed in the 1990s. The first commercialized GM crop was a TOMATO called Flavr Savr (resistant to rotting), marketed in 1994 by a US-based company, Calgene. Since then, many GM crops have been commercialized. More than 250 million hectares of GM crops are planted annually in more than 20 countries and by more than 10 million farmers. The US grows more than 50% of all the GM crops in the world. The other most important producing countries are, in order, Argentina, Brazil, Canada, India, China, Paraguay and South Africa. Canada accounts for about 6% of the world production. The International Services for the Acquisition of Agri-biotech Applications (ISAAA) maintains records of global acreage and a database of the global status of commercialized transgenic crops.

Commercialized GM crops include herbicide-resistant CANOLA, a STRAWBERRY variety engineered to survive in colder temperatures, cold-tolerant WHEAT and INSECT-resistant CORN and cotton. More recently "Golden rice" (modified to produce the provitamin A) has been targeted for countries where the population faces dietary vitamin A deficiency. Canada has approved more than 100 GM crops and foods containing corn (resistant to corn borers and herbicides), canola (resistant to herbicides), POTATO (resistant to Colorado potato beetles), tomato (slow ripening), SQUASH, SOYBEAN, sugar BEET, FLAX and cottonseed oil. However, herbicide-resistant canola remains the principal GM crop of Canada.

The Regulation of Genetically Modified Foods

HEALTH CANADA is responsible for the approval and regulation of GM foods in the country. It assesses the safety of all genetically modified and other novel foods proposed for sale in Canada. Health Canada requires companies that develop GM crops to submit detailed scientific data for review before GM foods can be approved for commercialization and marketed in Canada. This data includes information on how the GM plant was developed; nucleic acid data that characterizes the genetic change; composition and nutritional data of the novel food compared to the original non-modified food; potential for new toxins; and potential for being an allergen. The Canadian Food Inspection Agency provides all federal inspection services related to food, and enforces the food safety and nutritional quality standards established by Health Canada. The Agency also oversees the environmental release of GM crops (under the Seeds Act) and feeds derived from genetically modified organisms, or GMOs (under the Feeds Act), making and enforcing decisions on safety. Canada has a voluntary labelling policy for GM foods. However, mandatory labelling is required if the introduced gene poses an allergy risk or if the food's nutritional content is changed. In the European Union, Japan and Australia labelling is mandatory for traceability and to give consumers a choice between GM and non-GM.

The Controversy over Genetically Modified Foods

GM foods and crops have been the subject of much controversy. Supporters feel that GM foods will help provide food to the ever expanding global population because of higher yields through resistance to herbicides, drought, cold and diseases as well as through improvement in the foods' nutritional content. Opponents of GM foods have many criticisms, which include long-term health effects, fate of foreign DNA upon digestion, labelling and consumer choice, intellectual property rights, ethics, and food security. Critics also have environmental concerns about the potential harm that GM foods can unintentionally cause to other non-target organisms, or the fact that GM plants could crossbreed with wild plants and the introduced gene be transferred to non-target plants. For instance, an herbicide-resistant crop could outbreed with a WEED and transfer the herbicide-resistant gene thus creating a "super weed" resistant to that specific herbicide. Insects could also become PESTICIDE resistant, making them difficult to control in the near future.

Intensive research on GM foods, including studies initiated by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) Codex Task force, has validated that generally GM food is as safe as its non-GM counterpart for animal and human consumption. Research has verified that other than allergic reactions, GM foods do not pose a threat to human or animal health.


Genetically Modified Animals

At present there are no transgenic food animals in the world approved for human consumption. However, scientific research shows that there are numerous ways in which transgenic livestock could contribute to society. Beneficial traits that could be introduced into food animals include the production of pharmaceuticals in the milk or milk with other unique characteristics, a faster growth rate, improvements in meat composition and a decreased environmental footprint.

The first transgenic food animal developed in Canada is an ATLANTIC SALMON that grows at a rate 2 to 6 times that of wild conventional salmon. These fish were developed at Memorial University by the introduction of a transgene consisting of the antifreeze protein gene promoter from ocean pout fish linked to a Chinook salmon growth hormone gene. They have been subject to extensive safety and environmental safety testing and a submission documenting human food safety went before the Food and Drug Administration in the United States in September 2010.

In 2000 transgenic PIGS trademarked Enviropig™, with a reduced environmental footprint, were produced at the University of Guelph. These pigs were developed by the introduction of a transgene composed of the mouse parotid secretory protein promoter linked to the Escherichia coli phytase gene. The pigs secrete the enzyme phytase in their saliva, which enables them to digest phytate, a compound present in cereal grains that accounts for 50 to 80% of the total phosphorus and is indigestible by monogastric animals, which include swine. The ability to digest the phytate reduces the phosphorus in swine manure by 35 to 65% depending upon the pigs' age and diet composition. This is important because in conventional pigs the phytate phosphorus passes through the digestive tract and is enriched in the manure. The manure is spread on agricultural land as a FERTILIZER, but when applied to meet the nitrogen requirements of plants, the phosphorus is in excess and when it rains, or in spring with melting snow, the runoff is enriched in phosphorus. The excess phosphorus in ponds and lakes causes excessive ALGAL growth that eventually reduces water quality and leads to killing fish.

Enviropig Safety Assessments

Because of the reduced environmental impact of the Enviropig™, applications including data on human food safety, animal feed safety and environmental safety have been submitted to Health Canada, the Canadian Food Inspection Agency and Environment Canada, respectively. Conditions for commercial production of the Enviropig™ that are compliant with the Canadian Environmental Protection Act are in place, but the transgenic pigs will not be released from confinement at the University of Guelph until assessments from Health Canada and the Canadian Food Inspection Agency have documented them as safe. A similar application has been made to the United States Food and Drug Administration.


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