What are GMOs? And How to Avoid Them

Boxes of vegetables

The very definition of nutrition is the process of providing or obtaining the food necessary for health and growth. Think of it this way: the food we eat provides the nutrients that are necessary for our bodies, like perfectly matched puzzle pieces. The food we eat each day has the potential to provide our bodies with what they need to thrive! However, we also have access to food products that contain “pieces” that may not fit quite right.

Remember that the first place our food comes into contact with our body is the gut, so it’s no surprise that there is a whole other ecosystem inside working to take the nutrients we need from our food and helping eliminate what we don’t. This ecosystem is known as the microbiome. In order to protect delicate processes of the microbiome, it’s important to carefully consider what we consume each day.

What are GMOs?

GMO stands for Genetically Modified Organism, which means that one organism (such as plants or animals) have been given genetic information from another organism. Dr. Rick Meilan, Molecular Tree Physiologist at Purdue University, explains it this way:

“Genes are made up of DNA, which is a set of instructions for how cells grow and develop. The second part is modified. This implies that some change or tweak has been made. Lastly, we have the word organism. When it comes to GMOs, many people only think of crops. Yet, an ‘organism’ isn’t just a plant; it refers to all living things, including bacteria and fungi.

With that in mind, GMOs are living beings that have had their genetic code changed in some way.” [5]
While cross-breeding has been a part of farming practices for centuries, mainly to produce a better crop, modern day technology has accelerated these changes through genetic engineering, meaning we are now able to produce plants and foods that may never have occurred in nature. Rather than crossing two plants out in the field, they insert a gene or two into individual cells in a lab.

It’s important to remember that every living thing contains its own unique DNA, which provides the instructions for how it will interact with its environment, including animals and humans. When foreign DNA from another species is combined with the original DNA through genetic engineering, a new species is created. These new organisms contain new proteins as a result of added genetic material. Proteins in the body do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs.

Genetic modification of living organisms produces combinations of animal, plant, bacteria and virus genes, which would not otherwise exist. The resulting changes are complex and may lead to significant changes in function.

Essentially, genetic engineering involves taking something old, something borrowed, and creates something new.

Why might food companies want to use GMO products?

According to Dr. Peter Goldsbrough, Professor of Botany and Plant Pathology at Purdue University, “when farmers plant their crops they generally worry about three things that could prevent a good yield: insects, weeds and weather. Most of the GM crops grown around the world today address problems caused by insects or weeds.” [4]

For example, a common GM trait is resistance to particular types of herbicides, such as glyphosate, so strong herbicides can be used to control weeds without affecting crops.

Dr. Goldsbrough goes on to say, “When it comes to insects, there are genetically modified plants that can repel only the very particular type of insect that feeds on it. With some crops, this has significantly lowered the need to apply pesticides. Other GM plants have been developed to be resistant to certain herbicides thus making weed control more straightforward and less expensive.”

In fact, as of 2015, 92 percent of corn, 94 percent of soybeans and 94 percent of cotton produced in the U.S. were genetically modified. [1, 2] Corn and soy are among the top 12 GMO foods, and the byproducts of corn and soy are used to make a wide variety of other foods you might recognize. [1]

Corn, in the form of high fructose corn syrup, and soy are found in cereals, protein powders, snack bars, and pre-packaged foods like chips or cookies, baby food, and even your dog’s food.

Furthermore, animals like cows and pigs are eating a more grain based diet, which is likely GMO if not labeled 100% grass-fed or organic. This means that the animal protein we consume can also contains GMOs.

The Center for Food Safety has a list of the most common GMOs, or the “Big Five” ingredients commonly found in processed foods: [1]

  • Corn: Corn flour, meal, oil, starch, gluten and syrup. Sweeteners such as fructose, dextrose and glucose.
  • Beet Sugar: Sugar not specified as 100 percent cane sugar is likely from GE sugar beets.
  • Soy: Soy flour, lecithin, protein, isolate and isoflavone. Also vegetable oil and vegetable protein when they are soy derived.
  • Canola: Canola oil (also called rapeseed oil)
  • Cotton: Cottonseed oil

GMOs and Health

GMO crops and foods have only been on the market for a relatively short period of time, about 25 years. Long-term studies have yet to be conducted on both animal and human consumption across the lifespan. The potential risks and dangers are still being discovered, but there is evidence to suggests GMOs may be harmful to health.
A review study from 2016 published in the journal Food Science and Human Wellness concludes that there are major risks associated with GMOs including toxicity and allergenicity. [3] Additionally, the Center for Food Safety identified additional concerns including antibiotic resistance, cancer, and loss of nutrition. [1]

Toxicity Concerns

Many GMO crops are engineered in a way that they have their own insecticides, which are known as Bt plants. They’re referred to as Bt because they incorporate a transgene that makes a protein-based toxin from the bacterium Bacillus thuringiensis. [4] Bt crops include maize, cotton, and soybeans. One of the concerns is that Bt insecticides share structural similarities with ricin, which is a dangerous plant toxin.
Furthermore, GMO foods are fairly unstable. [1] Consider that each genetically engineered food receives an insertion of a new gene. Each genetic insertion creates the added possibility that formerly nontoxic elements in food could actually become toxic.
Another concern is the use of pesticides and herbicide residue on GMO crops, which have been linked to endocrine disruption and toxicity to human cells. [6]

GMOs and Allergies

When an organism is genetically modified, it means that expression of the natural components changes, which can worsen the allergen it contains. For example, a 2016 review article discusses the production of soybeans enriched in the amino acid methionine. [3] This enriched synthesis is the result of a gene isolated from Brazil nuts. As a consequence, some consumers allergenically sensitized to these nuts have allergic reactions to the transgenic soybean. [3]

How to avoid GMOs

The Non-GMO Project is a “mission-driven nonprofit organization dedicated to building and protecting a non-GMO food supply.” [7] The Non-GMO Project Product Verification Program is a third-party verification for non-GMO food and products. You can see their label on several items, so look for the butterfly label.

  1. Buy organic: the USDA National Organic Standards prohibit the use of GMOs.
  2. Choose items with the non-GMO verified label, look for the butterfly by the non-GMO project or NSF Non-GMO Certified logo.
  3. Shop local!
    Shopping at small local farms can also help to reduce your likelihood of buying and consuming GMOs. Ideally a farm will be certified organic, but since this is an expensive certification, sometimes you may find that a local farm doesn’t carry that title yet is clearly practicing healthy farming techniques and not growing GMO crops. Talk to the farmers at your local farmers markets, visit the farms yourself and get to know the non-GMO options where you live.
  4. Read labels carefully!
  • In North America, eleven crops from GMO seed are commercially available: sugar beets, canola, soy, cotton, corn, zucchini, yellow summer squash, potatoes, alfalfa (animal feed variety only), papaya and apples (Arctic brand).
  • Milk, cheese, eggs, meat and poultry could all be from animals that were given GMO feed or who graze on GMO contaminated soil. Choose organic or non-GMO verified whenever possible.
  • Among the most prevalent GMO crops, corn, canola, soy, cotton and sugar beets, end up as additives in all kinds of packaged foods in the form of corn syrup, oil, sugar, flavoring agents, thickeners, among other. Choose organic or non-GMO verified.
  • Many frozen fruits and vegetables are non-GMO unless from one of these five high-risk crops: corn, Hawaiian papaya, edamame (soybeans), zucchini and yellow summer squash. Choose organic or non-GMO verified for those five and watch out for other ingredients that might be from a risk crop.
  • As long as you avoid corn and soy, choosing dry beans, grains, nuts and seeds is a great way to go non-GMO.


  1. About Genetically Engineered Foods
  2. Recent Trends in GE Adoption
  3. Genetically modified foods: A critical review of their promise and problems
  4. Why Do We Use GMOs?
  5. What Are GMOs?
  6. Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines
  7. Non-GMO Project