We hear a lot about Genetically Modified Organisms, or GMOs, but what exactly are they, and why should we bother worrying about them? A Genetically Modified Organism is an organism whose genetic material has been altered using genetic engineering techniques. Organisms that have been genetically modified include micro-organisms such as bacteria and yeast, insects, plants, fish, and mammals through the gene splicing techniques of biotechnology (also called genetic engineering, or GE). This experimental technology merges DNA from different species, creating unstable combinations of plant, animal, bacterial and viral genes that cannot occur in nature or in traditional crossbreeding. Genetic modification involves the insertion or deletion of genes. When genes are inserted, they usually come from a different species, which is a form of horizontal gene transfer. In nature this can occur when exogenous DNA penetrates the cell membrane for any reason. To do this artificially may require attaching the genes to a virus or just physically inserting the extra DNA into the nucleus of the intended host with a very small syringe, or with very small particles fired from a gene gun. However, other methods exploit natural forms of gene transfer, such as the ability of Agrobacterium to transfer genetic material to plants, or the ability of lentiviruses to transfer genes to animal cells.
GMOs are the source of genetically modified foods, and are also widely used in scientific research and to produce goods other than food. Virtually all commercial GMOs are engineered to withstand direct application of herbicide and/or to produce an insecticide. Despite biotech industry promises, none of the GMO traits currently on the market offer increased yield, drought tolerance, enhanced nutrition, or any other consumer benefit.
So, what are the main impacts, risks and hazards of Genetically Modified Organisms?
While theoretical discussions have covered a broad range of aspects, the three main issues debated are tendencies to provoke allergic reaction (allergenicity), gene transfer and outcrossing.
The most obvious nutrition concern with genetically modified organisms is the risk of allergic reactions. More than 90% of food allergies occur in response to specific proteins in milk, eggs, wheat, fish, tree nuts, peanuts, soybeans, and shellfish. The risk for allergic reaction stems from a protein from one of these foods incorporated into a food that does not cause a known allergic reaction. For example, if an individual who has a known allergy to peanuts unsuspectingly consumed a genetically modified organism that contained the allergenic protein from the peanut, conceivably the individual would experience an allergic reaction. This concern has been addressed with FDA measures put into place to prevent such a scenario. The FDA requires that each presenter of a genetically modified organism show scientific evidence that they have not incorporated an allergenic substance into their product. If the presenter cannot produce this evidence, the FDA requires a label on the product to alert the consumer of its possible allergic reaction.
Gene transfer from GM foods to cells of the body or to bacteria in the gastrointestinal tract would cause concern if the transferred genetic material adversely affects human health. This would be particularly relevant if antibiotic resistance genes, used in creating GMOs, were to be transferred. Although the probability of transfer is low, the use of technology without antibiotic resistance genes has been encouraged by a recent FAO/WHO expert panel.
Outcrossing is the movement of genes from GM plants into conventional crops or related species in the wild, as well as the mixing of crops derived from conventional seeds with those grown using GM crops, and may have an indirect effect on food safety and food security. This risk is real, as was shown when traces of a maize type which was only approved for feed use appeared in maize products for human consumption in the United States of America. Several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM crops and conventional crops are grown.
According to the World Health Organization (WHO), there is a very real risk of outcrossing, which refers to the transfer of engineered genes (transgenes) from genetically modified crops to conventional, cultivated plants or to related crop species in the wild. This may happen by means of wind, insect pollination, or other transfer. The foreign genes can cross with and contaminate these other species, resulting in a hybridization of the genetically modified crop plant with a non-GMO plant. This could radically alter entire ecosystems if the hybrid plants thrived.
Another hazard is the increased use of herbicides and pesticides. Scientists estimate that crops that are genetically modified to be herbicide-resistant tend to greatly increase the herbicide use. Knowing that their crops are more herbicide tolerant, farmers are more likely to use these often-toxic chemicals more liberally. Many genetically modified crops are engineered to produce their own pesticides and may even be classified as pesticides by the EPA. This strategy, in turn, adds even more pesticides into our fields and food than ever before.
The top ten Genetically Modified Food crops:
Corn: Our number-one agricultural commodity. In 2000, 79.5 million acres of harvested cropland in the U.S. were corn, 25% of which was genetically engineered. This includes Bt and Roundup Ready corn varieties.
Soy: The number-two U.S. agricultural commodity. Sixty percent of processed foods contain soy ingredients, and 82% of edible fats and oils consumed in the U.S. are soy-based. In 2000, 54% of the 74.5 million acres of soybeans grown in the U.S. was Roundup Ready soy.
Potato: Currently, the only GE potato is a Burbank Russet variety, marketed under the name NewLeaf. This Bt-producing plant is lethal to the Colorado potato beetle – and possibly to beneficial insects.
Tomato: The first GE tomato, the Flavr Savr, was introduced commercially in 1994, but flopped because it proved tasteless. Since then, other varieties, including a cherry tomato, have been genetically engineered to delay ripening and extend shelf life.
Canola: Of the 15 million acres of canola grown in the U.S. and Canada annually, 35% is GE, mostly for herbicide-resistance.
Cottonseed Oil: In 2000, 61% of the 15.5 million acres of cotton grown in the U.S. was genetically engineered. Every year, half a million tons of cottonseed oil makes its way into salad dressings, baked goods and snack foods. About 1.4 million tons of cottonseed meal is fed to livestock annually.
Papaya: More than one third of Hawaiian papayas have been genetically engineered to withstand the papaya ringspot virus. Organic papaya growers in Hawaii worry that the pollen from GE papaya trees will contaminate their crops.
Radicchio: Currently one variety of radicchio, called Seed Link, has been genetically engineered to be resistant to the herbicide glufosinate.
Squash: Several varieties of summer squash have been genetically engineered to resist mosaic viruses. Some scientists are concerned that resistance to the virus may spread to weedy relatives, such as gourds, found in the U.S., creating invasive superweeds.
Salmon: A company called Aqua Bounty has engineered a salmon with genes from two different fish species so that it grows much more quickly than non-GE salmon. The company now seeks FDA approval to market this fish for human consumption. Escaped into the environment, (which is inevitable on fish farms), the GE fish may be larger and more aggressive, eat more food, and mate more often, though their offspring are less fit to survive in the wild, raising the possibility of wild species extinction. Human health effects are also relatively unknown. Currently, research on transgenic strains of 35 fish species world-wide is underway.
So with this information it is now your chance to accept it or reject it. If you accept it, don’t blame the politicians and scientists for pushing it down your throat. Don’t try to pass on the buck. It will happen only if you remain a silent spectator. Rejecting it and being aware of what you and your family actually eat is a lot more work, and it will probably be more expensive, but is this really enough to stop you from doing all you can to preserve your family’s health? I urge you to rethink your habits, this often done best in a family meeting, and decide to live a healthy and eco-friendly life.