Myths and facts about GMOs

Text written by Julie Potvin-Barakatt, October 19, 2010.

Genetically modified organisms (GMOs), also called transgenic organisms (organisms to which one or more genes have been added, removed, or modified), have been raising controversy since they first appeared in the 1970s. The abundance of information circulating on the subject has often had the effect of drowning the facts in an ocean of misunderstanding and half-truths, causing confusion in the population. Whether for or against these bacteria, plants, or animals born in laboratories, our convictions must be based on the right facts. In this text, we will discuss some of the myths and facts about these highly technological organisms.

GMOs are ubiquitous in our supermarkets.
Myth. Meat, fish, and seafood found on supermarket counters are totally free of GMOs. This is also the case for the fruit and vegetable counter, with the exception of a papaya grown in the United States that is resistant to a virus. A few other GMO fruits and vegetables (potato, tomato, squash) have received the approval of the Plant Biosafety Office (PBO) of the Canadian Food Inspection Agency (CFIA) to be marketed in our country; at present, though, no supermarket has them in inventory. So where are the GMOs hiding? The vast majority are finding refuge in processed products! Indeed, because 99% of GMO plants grown in the world are canola, soybean, corn (but not sweet corn), and cotton, GMOs are possibly hidden in the starch or soy lecithin in your favorite cookie. Since there are no regulations requiring them to appear on labels in Canada, there is no way to know if a particular cookie is made with starch coming from GMO corn. Rest assured, however, that in your mouth there is nothing left that is a GMO. In effect, starch has the same composition, whether it is extracted from transgenic corn or not.

When it’s not organic, it’s surely GMO.
Myth. However, the opposite is true: organic products never contain GMOs, nor do they contain chemical pesticides or chemical fertilizers. “Organic” products were in existence long before the invention of GMOs. GMO foods have been excluded from the definition of “organic” foods since their arrival on the market in 1995, because we cannot claim without a doubt that they have no impact on our health and the environment. This exclusion, however, is controversial. Some transgenesis advocates consider this technique to be a simple extension of traditional hydridization methods. Others see them as an alternate solution to chemical fertilizers and pesticides. It is true that some GMO plants have led to the reduction in the use of these substances but in fact, most GMO plants have led to an increase in the quantity of herbicides in the environment.

Most food-related GMOs are designed to make agriculture more efficient.
Fact. No fewer than 98% of the GMOs grown worldwide have borrowed from another living being a gene that confers tolerance to herbicides or a gene that allows it to produce an insecticide, or both. The herbicide tolerance gene allows plants to survive crop-dusting while undesirable weeds are eliminated. The insecticide-producing gene confers toxicity to the plant, protecting it from pests. In the latter case, the gene from a toxic protein belonging to the bacterium Bacillus thuringiensis (Bt) is used. It is easy to work with these characteristics that involve a single gene. The GMOs thus formed are known as “first generation” GMOs. Several “second generation” GMOs are on trial in laboratories or in contained fields. Research is geared to create plants resistant to drought, cold, and disease, plants that are more nutritious, more flavorful... all characteristics that require the use of more than one gene each. These new transgenic plants will be required to pass a very rigorous evaluation before appearing on the supermarket shelves.

GMO plants risk transferring antibiotic resistance genes to bacteria.
Fact. This is a potential threat: although the transfer has never been observed in the environment, it has occurred in the laboratory under very controlled conditions. In most plants, the antibiotic resistance gene is borrowed from a bacterium and is part of the genetic modification process. In effect, when we transform the genome of a plant organism, we introduce the antibiotic resistance gene into its cells at the same time as the gene of interest (e.g., the gene of the toxic protein of Bt). The cells of the transformed plant are then grown in the presence of the antibiotic to ensure that only the cells that incorporated the resistance gene of interest will grow, thus selecting at the same time the cells that have incorporated the gene of interest. Because bacteria are known to exchange genes, there is some concern that some of them would succeed in incorporating the antibiotic resistance gene from the GMO plant. To definitely eliminate this risk, researchers have started removing the GMO marker gene from the plants once the cell selection process has been completed since this gene is, in any case, no longer necessary to the plant. This preoccupation therefore has tended to disappear.

GMO plants are all sterile.
Myth. On the contrary, as is the case with normal plants, approved GMO plants are capable of reproducing. This actually constitutes a threat for biodiversity. In effect, it is feared that the pollen from transgenic plants, free to travel outside the field where it was cultivated, will crossbreed with wild flora. The new hybrids created could be more competitive than their neighbors and dominate them. Because the probability that this would occur is low but not null, there is interest in creating seeds that would not be viable past the first generation. These suicide-seeds would have the added advantage of pleasing seed producers because they would no longer have to resort to contracts forbidding farmers from keeping seeds to sow from one year to another. At present, there is an international moratorium suspending research aiming to render plants sterile because the subject raises some important ethical issues.

GMO Atlantic salmon, in the process of being homologated in the United States, are threatening wild salmon.
Myth. Since 99% of them are sterile and the fish are raised on fish farms on land, there is no need to worry that transgenic salmon will dominate their wild relatives. At least, this is what AquaBounty Technologies, poised to be the first company to clear a path to selling GMO animals in our supermarkets, maintains. GMO salmon, baptized AquAdvantage salmon, grow to adult size twice as rapidly as other salmon because they have the advantage of a gene extracted from the chinook, a Pacific salmon that produces a growth hormone. The American FDA (U.S. Food and Drug Administration) maintains that the product is healthy and safe for the environment and is gearing up to authorize it within its borders. An independent committee of experts from the United States and Canada does not concur and is recommending that the FDA carry out more studies before marketing the product. In our country, Health Canada must carry out its own scientific evaluations before authorizing the marketing of the accelerated growth salmon.

GMO foods hide allergens.
Myth and fact. Having the wind knocked out of you, not because you ate a food allergen, but a fragment of a food allergen hidden in another food: what a scandal that would be! The manufacturing of GMO food is not immune to this type of trespassing. Rest assured, however, that for each GMO marketed in this country, Health Canada carefully investigates the risks of intoxication and allergic reaction. For example, it refused to market a variety of soybean that contained genes from the Brazil nut even if it was destined exclusively for animal consumption. In short, are there any known allergens in GMOs? All those that were approved and marketed have come up clean. Also note that, according to studies, GMOs are not responsible for the increase in food allergies observed in recent years.

GMO foods are less nutritious.
Myth. GMOs are subjected to the substantial equivalence principle. Before they are authorized to be put on supermarket shelves, new transgenic foods are rigorously analyzed. We make sure their nutritional content is equivalent to that of conventional foods and that they pose no danger for humans or for the environment. In Canada and in the United States, when the nutritional content of a GMO food is judged equivalent to that of a traditional food, it is treated in the same way as the latter and not subjected to a traceability system leading to labeling.

GMOs are also insulin, several vaccines, and other medications.
Fact. Before their arrival on our dinner plates, GMOs invaded the pharmaceutical industry. Since 1983, Canadian diabetic men and women have been injecting themselves with insulin manufactured by GMO bacteria. How are they manufactured? The human gene responsible for producing insulin is injected into the DNA of the bacteria. This DNA patching is carried out by enzymes that act like scissors and glue: they cut and reassemble DNA in very precise areas. The modified bacteria then become small plants that synthesize large quantities of the human hormone, which is subsequently purified. The vaccine against the hepatitis B virus is another example of a GMO product. The latter is produced from GMO yeasts that produce the surface proteins (antigens) of the virus used to manufacture the vaccine. Other pharmaceutical molecules such as erythropoietin (or EPO, a hormone that facilitates the transportation of oxygen in the blood) are obtained through growing genetically modified hamster cells.

GMO mice are used in laboratories.
Fact. The mice are not the only ones. A multitude of GMOs are born in laboratories and used only for fundamental research. To genetically modify an animal, we need the stem cell of an embryo. Stem cells can give birth to all types of cells: adipose, cardiac, blood, muscular, etc. First, the gene of the stem cell is modified; then this cell is introduced into an ovum that has been previously emptied of its DNA. In this environment, the modified stem cell develops into an embryo, giving birth to a completely transgenic animal. In research, mice are the perfect guinea pigs because they are small and reproduce rapidly. In effect, mice known as “knock-out” mice allow us to decode the human genome. We inflict specific mutations on certain genes and the result gives us information on the gene in question. We can also modify some genes so that the mice develop certain human diseases (cancer, cystic fibrosis, diabetes...) leading to a better understanding of the functioning of these diseases. Rest assured that, as is the case for laboratory animals, the use of transgenic rodents is subject to strict containment regulations and severe standards to reduce the suffering of these mice to a minimum and to reduce the number of individuals involved in each study.

Making money is man’s primary motivation in producing GMOs.
Fact. Profits are the driving force in the development of GMOs at several levels. Companies producing GMOs, such as Monsanto and Dow AgroSciences, are in a race to discover new genes, develop new transgenic plants, and develop new methods and tools in order to gain large patent portfolios. GMO farmers are both victims and accomplices in this lucrative market. Indeed, the purchase of GMO seed is more expensive than the purchase of traditional seed and must be repeated each year since patents protect the manufacturers by forbidding the reuse of seed from one year to the other. Nevertheless, when well managed, this purchase ensures a better yield and facilitates and reduces farm work.

GMOs, promising?
Fact. This sector of biotechnology is thriving. In the next few years, it could offer more nutritious food, synthesize new medication, decrease pollution, produce plastics, and generate energy, as long as public opinion welcomes it and, even more importantly, as long as GMOs do not remain under the exclusive control of a few companies. For example, at the University of Guelph in Ontario, a dozen ecological pigs are being studied. Baptized “Enviropig,” these pigs are genetically modified to produce an enzyme in their saliva that digests the phosphorus in their food. Their manure contains 70% less phosphorus than that of conventional pigs, reducing the environmental repercussions of raising them. We cannot predict when this pork will make its way to the meat section of your supermarket, since there are several long steps to complete before it can be commercialized.