Genetically Modified Food (GMOs)

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Latest Edit: Hector 2014-02-19 (EDT)

Article Genetically modified food, IHP,June/July 2008

Genetically modified organisms (GMOs) are defined as organisms which have had their genetic material (DNA) altered through engineering. There are many terms for the genetic modification of food including: modern biotechnology, gene technology, recombinant DNA technology and genetic engineering. Avoiding GMO foods is recommended especially for those of child bearning age.


To create a genetically modified food, genes from one species such as fish, insects, plants, animals, bacteria and viruses, are forced into the DNA of other species – often one that is unrelated. The result is a new organism that is different from that which would normally appear in nature, and consequently very little is known about their health risks or benefits. [1]

Genetically modified foods first appeared in 1994 with the introduction of the first commercially grown genetically modified tomato called FlavrSavr, which was created to ripen without softening in the process. Calgene, a subsidiary of the multinational agricultural biotech company Monsanto was responsible for this launch. Monsanta is currently the leading producer of genetically engineered seed and provides the technology for 90% of all genetically engineered seeds used in the United States. [2]

The introduction of genetically modified seeds was initially brought to market in an attempt to reduce the amount of insect damage to crops. This new breed of seeds could produce or with-stand the application of herbicides which ensured more robust and reliable harvests, and the reduction of crop scarcities. [1]

Use and Consumption

Here is a summary of crops, foods and food ingredients grown in the US that have been genetically modified as of May 2010:[3] (number in parentheses represents the estimated percentage that is genetically modified.)

  • Soy (91%)
  • Cotton (71%)
  • Canola (88%)
  • Corn (85%)
  • Sugar Beets (90%)
  • Hawaiian papaya (more than 50%)
  • Alfalfa (debate currently at Supreme Court),
  • Zucchini and Yellow Squash (small amount)
  • Tobacco (Quest® brand)

Other Sources of GMOs include:[3]

  • Dairy products from cows injected with the GM hormone rbGH
  • Food additives, enzymes, flavorings, and processing agents, including the sweetener aspartame (NutraSweet®) and rennet used to make hard cheeses
  • Meat, eggs, and dairy products from animals that have eaten GM feed
  • Honey and bee pollen that may have GM sources of pollen
  • Contamination or pollination caused by GM seeds or pollen
  • Some of the ingredients that may be genetically modified include:
  • Vegetable oil, vegetable fat and margarines (made with soy, corn, cottonseed, and/or canola)
  • Ingredients derived from soybeans: Soy flour, soy protein, soy isolates, soy isoflavones, soy lecithin, vegetable proteins, textured vegetable protein (TVP), tofu, tamari, tempeh, and soy protein supplements.
  • Ingredients derived from corn: Corn flour, corn gluten, corn masa, corn starch, corn syrup, cornmeal, and High-Fructose Corn Syrup (HFCS)

In Canada, some estimates suggest that as many as 30,000 different products on grocery store shelves have been genetically modified or contain genetically engineering ingredients. This is largely due to the fact that many processed foods contain soy, a crop of which more than 90% is genetically engineered in North America.

For more information on foods that may be genetically modified visit [2], [3] or [4].


The genetic engineering of food is a topic that is hotly debated. Some see the economic and nutraceutical benefits of this process and others argue that through the use of GMOs, food producers are tampering with nature and re-engineering humanity to the detriment of the environment and our health.

Risks Associated with GMOs

The risks and disadvantages associated with GMOs are extensive both for human health and for agriculture.[1], [4], [5]

Human Health

  • Affects on Overall Health
Article Don't Look, Don't Find: Health Hazards of Genetically Modified Foods, Vital Link; 2013 Spring
  • There are many disease that have been associated with GMOs including:[6]
Article Genetically Modified Food and Your Health, NDNR [5], 2011 January
  • The specific gene added to most corn crops is a type of Bt-toxin which is produced from Bacillus thuringiensis bacteria. These toxins, including Cry1Aa toxin of B. thuringiensis, are known as "pore-forming toxins" because they cause essential minerals needed for cell survival to perforate the cell membrane and kill the host. These proteins are highly dynamic and can change quickly in different environments, such as inside or outside of the cell membrane. Consequently it is difficult to study their precise mechanisms of action and basic functioning, or their risks on the human body once consumed.[7] Bt-toxin survives digestion and has the properties of an allergen.[6] Bt-toxin may be associated with infertility and decreased birth weight, liver and kidney toxicity, blood pressure problems, allergies, infections, higher blood sugar and anemia.[6]
  • Allergies It is believed that GMOs are partly responsible for the dramatic increase in allergies. The current thinking is that the imported genes in GMOs produce a new protein which has never before been present, which in turn may trigger allergic reactions in the body.[8], [9] [3]
  • Reports have indicated that people with compromised immune systems or pre-existing allergies may be particularly susceptible to the effect of the Bt toxins from GMOs, however health issues after exposure are not limited to these groups. For example, when Bt toxin was sprayed over areas around Vancouver and Washington State to fight gypsy moths in the mid-1980's, approximately 500 people reported allergic reactions and flu‐like symptoms after exposure.
  • The possible causes for an increase in allergies include:[6]
  • digestion impaired
  • new allergen created
  • known allergen increased
  • herbicide residues increased
  • Roundup Ready protein may be allergenic
  • GMOs and Pregnancy The risk of GMOs seems to have a tremendous impact on fertility, birth weight and overall health of a fetus.[6]
  • In 2010, a study, Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, was published in the Journal of Reproductive Toxicology. The study examined the blood of 30 pregnant women and 39 nonpregnant women. The study specifically measured whether certain substances were detectable in the women's blood serum after exposure to GMOs. This study clearly demonstrated the presence of pesticides associated with genetically modified foods in maternal, fetal and nonpregnant women’s blood. 3-MPPA and Cry1Ab toxins were clearly detectable and appeared to cross the placenta to the fetus as evidenced in the table below. The authors concluded that given the potential toxicity of these environmental pollutants and the fragility of the fetus more studies are urgently needed.[10]
  • Glyphosate, brand name Roundup
  • Gluphosinate, a broad-spectrum herbicide
  • AMPA, aminomethyl phosphoric acid, a metabolite of glyphosate
  • 3-MMPA, 3-methylphosphinico propionic acid, a metabolite of gluphosinate
  • Cry1Ab, the Bt toxin of gluphosinate
Toxin Maternal Fetal Cord
3-MPPA 100% 100%
Cry1Ab 93% 80%

  • Alteration of Human DNA The digestive tract is the first and largest point of contact with foods. As such, FDA scientists have expressed marked concern over the possibility of inserted genes transferring into the DNA of bacteria which resides in the human digestive tract. Scientists are specifically concerned about antibiotic resistant marker (ARM) genes which are used during gene insertion to help scientists identify which cells successfully integrate this foreign gene during the GMO process.[1] [11]
  • One FDA report indicated that ARM genes present a serious health hazard due to the possibility that they have the ability to transfer to bacteria, which in turn could create super diseases resistant to antibiotics.
  • While the biotech industry has indicated that gene transfer from genetically modified foods was not possible, a human feeding study concluded that the genetic material in soybeans which made them herbicide tolerant, did in fact transfer into the DNA of human gut bacteria and continued to function. This would suggest that after consumption of genetically modified food the foreign GM proteins may continue to be produced in our intestines. Of equal concern is the possibility of these foreign genes ending up inside our own DNA within the cells of organs and tissues.
  • Alteration in Nutrient Levels The nutritional level of GMOs is altered.[6]
  • Increase in anti-nutrients (such as soy lectin), allergens (e.g., trypsin inhibitor), and lignin (which are related to disease)
  • Toxic Load A study to investigate the possible subchronic toxicological effects of GM cereals on mammals and humans was undertaken in 2009. These substances had never before been an integral part of the human or animal diet, and the health consequences for those who consume them, especially over long time periods were relatively unknown. In this study three different types of GM corn (NK 603, MON 810 and MON 863), were fed to rats for 90 days. This was the longest in vivo test regarding the consumption of GMOs performed to date. The animals were monitored for numerous blood and organ parameters, specifically the kidney and liver.[12]
  • The study concluded that signs of hepatorenal toxicity and damage occurred due to the new pesticides (herbicide or insecticide) present specifically in each type of GM maize. It also indicated that unintended metabolic effects due to the mutagenic properties of the GM transformation process could not be excluded. Other negative effects were also observed in the heart, adrenal glands, spleen and haematopoietic system. Overall, the study highlighted that there was a clear negative impact on the function of liver and kidneys in rats consuming GM corn varieties for just 90 days.
  • Separate additional studies, also investigating the effects of GMOs on the liver of rats and rabbits have shown the following: [13] [14] [15]
  • Rats fed the GNA lectin potatoes had smaller and partially atrophied livers
  • Rats fed Monsanto’s Mon 863 corn, engineered to produce Bt‐toxin, had liver lesions and other indications of toxicity
  • Rabbits fed GM soy showed altered enzyme production in their livers as well as higher metabolic activity
  • Microscopic analysis of the livers of mice fed Roundup Ready soybeans revealed altered gene expression and structural and functional changes. Many of these changes reversed after the mice diet was switched to non‐GM soy.


There are many potential risks and disadvantages to agriculture as well, including:[1], [4], [5]

  • Unpredictable alterations and mutations in DNA. The DNA of the genetically modified plant can differ as much as 2-4% from its natural parent plant.
  • Altering of human cell chemistry.
  • Introduction of unidentifiable toxins and allergens.
  • Reduction of biodiversity due to the loss of important old seed varieties that contain essential genetic variance.
  • Contamination of organic and conventional crops through accidental spread of genetically modified organisms to nearby farms.
  • Development of superweeds and superpests which can lead to increased use of toxic pesticides
  • Development of antibiotic resistant pathogens. Experts estimate that glyphosate (Roundup) resistant weeds have infested close to 11 million acres in the US and that there are currently more than 130 types of weeds that have developed herbicide resistance in more than 40 US States.[6]
  • Bioaccumulations of pesticides and heavy metals in milk, fish, poultry and meat products due to presence of GMO grains in animal and fish food.
  • GMO crops have resulted in over 30% increase in the use of herbicides including Roundup. Roundup is known to:[6]
  • chelate trace minerals from the soil
  • dismantle plant defenses
  • destroy beneficial microorganisms
  • promote pathogenic organisms
  • remain in the soil and influence later crops.

Perceived Advantages

The reported perceived advantages for GMOs include:[4] [5]

  • Increased resistance to disease, insects, herbicides and pesticides. Upon exposure, the plants are less likely to be harmed or killed.
  • More robust harvests and products
  • Increased precision and selectivity in crop production
  • Harvest tend to spoil less quickly and products are more durable
  • Allows for the tracing of crops by farmers
  • Potential to add vitamins and minerals to the crops. Improved nutrient content of foods might help to reduce malnutrition on a micro and macro scale
  • Reduced production costs and prices for consumers
  • Ability to yield more crops from less arable land

Many of these reported advantages have been disproved over time or have been shown to have risks that out way the advantages.


  • Canada
  • Health Canada indicates that it is a seven to ten year process to research, develop, test and assess the safety of a new genetically modified food, and manufacturers and importers who wish to sell or advertise a GM food in Canada, must submit data to Health Canada for a pre-market safety assessment, as required under Division 28 of Part B of the Food and Drugs Regulations. [16]
  • Labelling for GMOs is currently not mandatory. A 2003 poll indicated that 88 per cent of Canadians believe that labels for GE foods should be made mandatory.

  • United States
  • The U.S. Food and Drug Administration currently requires labeling of GE foods if the food has a significantly different nutritional property; if a new food includes an allergen that consumers would not expect to be present or if a food contains a toxicant beyond acceptable limits.
  • Mandatory labeling of genetically engineered (GE) foods in the United States has been proposed, but not enacted, at the national, state, and local levels.

  • Other Countries
  • Mandatory labelling is currently enforced throughout Europe, Australia, New Zealand, China and Japan.


  1. 1.0 1.1 1.2 1.3 1.4 Pitchford Paul (2002) Healing with Whole Foods: Asian Traditions and Modern Nutrition Third Edition North Atlantic Books. Cite error: Invalid <ref> tag; name "Healing_with" defined multiple times with different content Cite error: Invalid <ref> tag; name "Healing_with" defined multiple times with different content
  2. ""Health Canada, Food and Nutrition, Information: Safety Assessment of the Flavr Savr Tomato" Retrieved 22 February 2011.
  3. 3.0 3.1 3.2 Institute for Responsible Technology, May 2007, "Genetically Engineered Foods May Cause Rising Food Allergies" Retrieved 22 February 2012.[1]
  4. 4.0 4.1 4.2 "Genetically Modified Food]" Retrieved 22 February 2012. Cite error: Invalid <ref> tag; name "Genetically" defined multiple times with different content
  5. 5.0 5.1 5.2 Busch Felicia (2000) The New Nutrition: From Antioxidants to Zucchini New York: John Wiley & Sons Inc.
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Smith Jeffery (2011) The Documented Health Risks of Genetically Modified Foods: Overwhelming Evidence of Harm AANP Conference 2011, Arizona. Cite error: Invalid <ref> tag; name "Smith" defined multiple times with different content
  7. "Science Daily" September 12, 2011, Retrieved 22 February 2012.
  8. Washington State Department of Health, “Report of health surveillance activities: Asian gypsy moth control program,” (Olympia, WA: Washington State Dept. of Health, 1993). 64 M. Green, et al., “Public health implications of the microbial pesticide Bacillus thuringiensis: An epidemiological study, Oregon, 1985‐86,” "Amer. J. Public Health" 80, no. 7(1990): 848–852 Retrieved 22 February 2012.
  9. N. Tomlinson of UK MAFF's Joint Food Safety and Standards Group 4, December 1998 letter to the U.S. FDA, commenting on its draft document, “Guidance for Industry: Use of Antibiotic Resistance Marker Genes in Transgenic Plants,”; (see pages 64–68) Retrieved 22 February 2012.
  10. Aris A, Leblanc S. "Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada" "ReprodToxicol" (2011), doi:10.1016/j.reprotox.2011.02.004, Retrieved 22 February 2012.
  11. "Institute for Responsible Technology" Retrieved 22 February 2012.
  12. de Vendômois JS, Roullier F, Cellier D, Séralini GE. "A Comparison of the Effects of Three GM Corn Varieties on Mammalian Health" "Int J Biol Sci" 2009; 5(7):706-726 Retrieved 22 February 2012.
  13. Arpad Pusztai, “Facts Behind the GM Pea Controversy: Epigenetics, Transgenic Plants & Risk Assessment,” Proceedings of the Conference, December 1st 2005 Retrieved 22 February 2012.
  14. Arpad Pusztai, “Can science give us the tools for recognizing possible health risks of GM food,” "Nutrition and Health" 2002, Vol 16 Pp 73‐84. 27 John M. Burns, “13‐Week Dietary Subchronic Comparison Study with MON 863 Corn in Rats Preceded by a 1‐Week Baseline Food Consumption Determination with PMI Certified Rodent Diet #5002,” December 17, 2002, Retrieved 22 February 2012.
  15. R. Tudisco, P. Lombardi, F. Bovera, D. d’Angelo, M. I. Cutrignelli, V. Mastellone, V. Terzi, L. Avallone, F. Infascelli, “Genetically Modified Soya Bean in Rabbit Feeding: Detection of DNA Fragments and Evaluation of Metabolic Effects by Enzymatic Analysis,” "Animal Science" 82 (2006): 193–199 Retrieved 22 February 2012.
  16. Health Canada "The Regulation of Genetically Modified Food"] Retrieved 22 February 2012.