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February 25, 2016

A Look Into the World of GMOs

By Avance Care’s Registered Dietitian: Kaci Adams, MS, RD, LDN

As a Registered Dietitian, the questions I receive regarding Genetically Modified Organisms (GMOs) continue to grow.  Many patients are concerned about the safety of these food products, with many believing they should be found in a science fiction movie and not in our food supply.  Below are answers to commonly asked questions.  Hopefully, this will help you decide if GMOs have a place in your and your family’s diet.

What are GMOs?

GMOs, first produced in 1996, are plants with artificially altered DNA and therefore, do not occur naturally in the environment.

Why are GMOs produced?

Primarily to increase plants’ tolerance to diseases caused by insects or viruses; to resist pesticides, herbicides, and drought; to enhance nutrient content (i.e. high-oleic soy); and to improve shelf-life. GMOs result in larger crop yields using less herbicides and at a lower cost of production, which is beneficial for the world’s growing population.

How are GMOs produced?

By transferring genes (rDNA) from one species to another; genes may be transferred between related or non-related species. GMOs resistant to insect diseases are produced by incorporating Bacillus thuringiensis (Bt) bacteria toxin gene into plants. Similarly, genes from viruses are added to plants to improve their resistance to certain diseases caused by viruses.  The herbicide glyphosate is added to plants to improve the plants’ resistance to herbicides.

What GMO foods are commercially sold in the US?

Corn, soy, cotton, canola, sugar beets, alfalfa, summer squash and papaya are the only GMO crops currently produced and sold in the US food market.  90% of all corn, soy, and cotton crops in the US are GMOs. Potatoes and apples are approved by the FDA, but not yet incorporated into our food supply. A genetically modified salmon engineered for rapid growth is currently under review and would be the first animal GMO introduced into our food market.

  1. Corn –Largest GMO crop in the US, is used to feed livestock and to produce high fructose corn syrup and corn starch.
  2. Soy– Second largest GMO crop in the US, is utilized to feed livestock and to produce soybean oil and soy lecithin (emulsifier found in most processed foods).
  3. Cotton-Employed to produce oily spreads (margarine and cottonseed oil) used in frying in restaurants and in packaged foods such as potato chips.
  4. Canola-90% of US canola is GMO and is developed to produce oil and emulsifiers found in processed foods.
  5. Sugar beets– Produces over 50% of the granulated sugar in our food supply.
  6. Alfalfa– Manufactured to feed cattle.
  7. Zucchini and Summer squash – Are produced to resist certain viruses; however, only 25,000 acres of GMO zucchini and squash are produced in the US.
  8. “Rainbow” Papaya– Are mostly grown in Hawaii to resist the ringspot virus.
  9. Apples– Manufactured to resist browning after sliced.
  10. Potatoes– Created to resist bruising and produce less acrylamide (cancer causing chemical).

**80% of processed foods contain many of these ingredients and thus contain GMOs.  It is important to read food labels for these ingredients if you are attempting to eliminate GMOs from your diet.

Are GMOs safe for human health?

 To put it simply, the National Academy of Sciences recently stated, “To date, no adverse health effects attributed to genetic engineering have been documented in the human population.” This comment is supported by more than 600 scientific publications ranging from short-term individual studies to meta-analyses on the safety of GMOs and human health.  With that being said, there have been two animal studies (one in rats and one in pigs) to link GMO feed consumption to negative GI outcomes (colon tumors).  However, the two studies have since been deemed scientifically unsound due to many flaws in statistical analysis and bias.

Are GMOs safe for the environment?

There is a risk of genes from GMOs to cross breed and contaminate non-GMOs, which can alter the natural state of our ecosystem.  However, the EPA and USDA performs risk assessments of all GMO crops to evaluate this possibility and minimize potential harmful consequences before allowing the crop to be produced. The engineering of insect resistant plants imposes slight risk of harm to honeybees, insects (i.e. monarch butterflies), worms, and other organisms.  The USDA’s Animal and Plant Health Inspection Service (APHIS) and the EPA evaluate any environmental impacts of such pest-resistant GMOs prior to commercial release. Additionally, the use of herbicide resistant GMOs can result in herbicide resistant weeds making it difficult to control weed growth.

Is the safety of GMOs regulated? Yes.

  1. The Environmental Protection Agency (EPA) regulates safety of all plants engineered with the Bt gene and pesticides created via biotechnology for the environment.
  2. The Food and Drug Administration (FDA) meets with developers of bioengineered foods to identify and discuss relevant safety issues such as toxicity and risk of allergy production of crops before incorporating them into the food market.
  3. The Biotechnology Regulatory Service (BRS) within the United States Department of Agriculture (USDA) regulates GMOs to ensure they are as safe for the environment as their non-GMO counterparts.

How do you know what foods do and do not contain GMOs? 

This is a difficult task in America.  America, unlike the European Union, China, and Australia, does not require foods with GMOs to be labeled.  Furthermore, the government does not regulate whether foods labeled “non-GMO” actually contain GMOs or not. Organic foods, regulated by the USDA, are mandated to be GMO free. Therefore, if you are trying to avoid GMO foods, buying organic is a safe bet.

Other important considerations:

 The choice to consume GMO foods is a personal one, but before you decide whether GMOs have a place in your diet, consider these additional facts.

  1. Incorporation of the Bt protein into GMO corn is a novel process, but the Bt protein has been used in organic spray for 60-70 years.  Therefore, people have been eating crops containing the Bt protein for years.
  2. Corn oil from GMO corn is biologically identical to oil from non-GMO corn because all proteins (including Bt protein) are removed during production of corn oil.
  3.  Hawaiian papayas were infected by the ringspot virus long before part of the virus started being engineered into the papaya to make it virus resistant. Consequently, we have been eating papaya infected with the ringspot virus for years.
  4. Plant cross-breeding has been around for centuries, which is why the fruits and vegetables we consume today are of much higher quality than the ones consumed 100 years ago.


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