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Glance at GMO

A Glance at GMO’s

The topic of GMOs can be confusing and certainly is hotly debated. As with any topic, the goal is to look at the facts and understand both sides of the issue. With an open minded investigation, you can make a personal choice about GMOs.


Definition: What is a GMO?

GMO stands for genetically modified organism. Scientists “design” plants by adding a gene, or genes, to change a characteristic of the plant. This process of introducing genes (DNA) from one organism to another is referred to as genetic engineering or bio-engineering.

Purpose of GMOs

Scientists can give a crop the ability to grow more quickly, survive in extreme weather, have a different color or resist pests. Genetic modifications can also increase the nutritional value or enhance flavor. The main reason for GMOs to date is crop protection from diseases spread by insects or viruses. Less diseased produce results in larger crop production and a more attractive product.

History of GMO’s

Our ancestors had no concept of genetics, but they were still able to influence the DNA of organisms by “selective breeding” and “artificial selection”. Selective breeding is the process of choosing the organisms with the most desired traits and mating them with the goal of passing on the desired traits to the offspring. Artificial selection has been used in a variety of plants. Ancient farmers in Mexico, about 10, 000 years ago, noticed that not all corn plants were the same. Some grew larger than others or had kernels that tasted better or were easier to grind. Farmers saved kernels from plants with the desirable characteristics and planted them for the next season’s harvest. Maize cobs became larger over time with more rows of kernels. This breeding takes much time and can be ineffective. Bio-engineering intentionally “assists” the breeding process. GMOs were first developed for non-food purposes: a bacteria to break down crude oil when faced with an oil spill (1980); a bacteria genetically engineered to produce enough hormone to make Humulin insulin (1982).

GMO’s hit grocery stores in the United States in 1994 with the Flavr Savr tomato which had a delayed-ripening and longer shelf life. Currently, GMO foods in the United States are only plants, such as fruit and vegetables.

GMO Crops

The Agricultural Marketing Service (AMS) provides this list of bio engineered foods to identify the crops of foods that are available in a bio engineered form throughout the world and for which regulated entities must maintain records.

  • Alfalfa (for animal feed)
  • Apple (Artic™ varieties), currently only available dried, not fresh
  • Canola, for canola oil
  • Corn, field corn for animal feed and processed foods, some sweet corn, but not popcorn
  • Cotton, for clothing, cottonseed oil and animal feed
  • Eggplant (BARI Bt Begun varieties)
  • Papaya (ringspot virus-resistant varieties)
  • Pineapple (pink flesh varieties)
  • Potato, white russet variety, only available in some locations
  • Salmon (AquAdvantage®), only available in Canada. Approved by the FDA but not yet for sale in USA
  • Soybean – for animal feed and processed foods, but not edamame or tofu varieties
  • Squash (summer), only a small percentage of the US crop
  • Sugar beet, for table sugar

GMO Concerns

The GMO debate is often not about GMOs at all. Often the debate regarding GMOs turns to concerns of who is controlling our food supply? Who is making sure our food is safe to eat? Who is ensuring the environment is protected? Are we catering to large corporations or small farmers? Do health and economic disparities take precedence in agricultural decision making? The focus of this article is GMOs and physical health.

GMOs and Health

Many are concerned that eating foods with GMO’s may increase health problems such as cancer, gastrointestinal tract problems, allergies, organ damage and disorders such as autism. After more than 20 years of monitoring by countries and researchers around the world such as The National Academy of Sciences in the United States, the European Food Safety Authority and The Royal Society in the United Kingdom, GMOs have not been found to exhibit any toxicity. Epidemiologic (population) studies comparing populations who consumed foods with GMOS with data from the UK and Western Europe where GMO food is not widely consumed found no pattern of differences among countries having specific health problems after the introduction of genetically engineered foods (GE) in the 1990s. The Academy of Nutrition and Dietetics analysis and review on GE foods did not reveal an association between adverse health effects and consumption of foods produced using genetic engineering technologies (cancer, food safety, inflammation, antibiotic resistance). We need to keep in mind that GMOs are not one thing. Transgenic crops, crops that have been artificially pollinated or injected with a gene to improve the resilience, growth and adaptability of the original crop, are GMO crops. Herbicide-tolerant crops are another type of GMO food.

Pesticides and Herbicides

Through genetic engineering, certain crops are able to resist insects that normally would over-run the crop. Examples are maize and cotton crops that contain genes from Bacillus thuringiensis or Bt, giving crops a built-in insecticide.

Genetic engineering created crops (soybean, cotton and maize—mostly used for animal feed) that survive when herbicides are used to destroy weeds among the planted crops. In particular, there are GMO crops resistant to the herbicide commonly known as RoundUp®. An herbicide contained in RoundUp® and many other weed control products is glyphosate. The media immersed the public with the announcement that glyphosate was classified as “probably carcinogenic (cancer causing) to humans” grade 2a. This was announced by The International Agency for Research in Cancer in March of 2015. In March 2017, the European Chemicals Agency did not classify glyphosate as a carcinogen. So what can we understand about the actual risk for cancer from glyphosate?

Cancer Risk in Perspective

Nearly everything we do has both risks and benefits. Certain activists and consumers desire a goal of zero exposure to risk. Zero risk and zero exposure are not possible. The International Agency for Research in Cancer uses a scale for cancer risk.

  • 1) definitely carcinogenic
  • 2a) and 2b), probably and possibly carcinogenic
  • 3) not classifiable, and
  • 4) probably not carcinogenic

Glyphosate is in group 2a for cancer risk. Also in this category are burning wood, work exposure as a hairdresser, frying at high temperatures and red meat. Group 1 items that are definitely carcinogenic are alcohol, wood dust, and solar radiation. Explained another way, dietary exposure to all pesticide residues poses a risk equal to drinking one glass of wine every three months. The contribution of glyphosate residues to cancer risk was so low as to be equal in risk to about half a tablespoon of wine per year. So, yes, there is level of RISK with glyphospate and this example demonstrates a low risk.

The Agricultural Health Study (AHS) which looked at lifetime exposure to glyphosate and 49 other pesticides in 57,310 individuals between 1993 and 1992, included a five year follow up. The median lifetime days of use was 48 days and the median lifetime years of use was 8.5 years. Those with higher use were more likely to drink alcohol more frequently and have a family history of cancer. In this large prospective study of pesticide applicators, there was no observed association between glyphosate use and overall cancer risk. However, there was some evidence of an increased risk of acute myeloid leukemia in those with highest glyphosate exposure compared with those who never used glyphosate. This study indicates the risk for the AML type of cancer is higher in those applying the pesticide.

To accurately assess consumer risks from pesticides, one needs to consider three major factors: the amount of residue on the foods, the amount of food consumed and the toxicity of the pesticides. The Environmental Working Group who publishes the Dirty Dozen and advocates strongly against all pesticides will also admonish the consumer that a diet rich in fruits and vegetables outweighs the risks of pesticide exposure. Again, one needs to consider that a risk level of ZERO is not possible.

Identifying GMO Foods and Labeling

Currently the United States and Canada do not require labeling of genetically engineered foods. By January 1, 2022, you will see a seal indicating “Bioengineered” on foods that meet the Agricultural Marketing Services’ definition of bioengineered foods. The standard defines bioengineered foods as those that contain detectable genetic material that has been modified through in vitro recombinant deoxyribonucleic acid (rDNA) techniques and for which the modification could not otherwise be obtained through conventional breeding or found in nature. Highly refined foods or ingredients that do not contain detectable modified genetic material are not bioengineered foods.

Consumers who prefer not to purchase or consume foods that are genetically modified or bio-engineered can buy foods labeled organic. Organic farmers cannot plant GMO seeds, allow their animals to eat GMO products or use any GMO ingredients in packaged products labeled as organic.


More than 2,000 studies and 20+ years of consumption by humans and animals have produced no evidence that GMOs pose a health risk. Any effort to prove beyond doubt that GMOS are safe will run into a roadblock. Nothing can be proven to be 100% safe. People and groups hold varying definitions of GMOs, adding to the complexity of the GMO issue. Do your own research. The Genetic Literacy Project, SciMoms and Safe Fruits and Veggies are groups that focus on science and not ideology—separating facts from emotions.

Stake your health on what we do know. You can reduce your risk of many chronic diseases by lifestyle choices: do not smoke, engage in routine physical activity, eat a balanced and varied diet with an emphasis on plant-foods (vegetables, fruits, whole grains, nuts and seeds) and avoid weight gain.

GMOs or No GMOs:
You can’t Outpace a Bad diet
“Doing crunches and continuing to eat poorly
Is like detailing your car and continuing to drive in the mud.”

Written by Charis W. Spielman, MPH, RD, CSO, CNSC
Certified Specialist in Oncology Nutrition


This article first appeared in the November 2019 edition of the HealthPerks newsletter.

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