GMO’s: What Are They and Are They Bad For Me?

author:  Kelly Gill, MS, RD, CSSD, LD


Genetic Engineering is not a new concept.  Yet, genetically modified crops have come under much scrutiny.  I plan to explain what exactly GMO’s are, what foods we find them in, and whether or not the fears are founded.



What are GMO’s?

First, GMO stands for Genetically Modified Organism.  This includes any living thing, not just the crops that we eat.  GMO’s have been used to produce medications that cure diseases, as well as vaccines that prevent diseases.

One example is insulin.  Decades ago, the medical world relied on insulin obtained from the pancreas of animals (pigs and cows) and purified to treat diabetes.  In the 1920’s, scientists were able to identify the gene that makes human insulin.  In the 1970’s they were able to isolate that gene inside bacteria and have the bacteria produce this “human” insulin, which they harvest and treat diabetes with today.  By the 1980’s this “human” insulin had taken over and animal insulin is only available in very limited supply now.  Considering the time and cost involved in obtaining animal insulin, this GMO technology is responsible for what is widely considered a huge medical advancement.

We have also used genetic engineering (GE) in the development of vaccines like cholera and hepatitis B.

Yet, when genetic modification of grains is considered, it’s met with tremendous resistance.  Why?  Why do we embrace technology in every other sense of the word, but not in this sense?


Are GMO’s safe for consumption?

The broadly held consensus by the vast majority of scientists is that the currently available GMO’s on the market are not any different than the non-GMO crop counterparts.  In effect, they are the same exact foods with just 1-2 genes added (out of the tens of thousands of genes).  Short-term studies (there are very few long-term studies available at this time) support this belief.  We have been eating GMO’s for more than 20 years, and so far, we have not seen any health-related issues at this time.

Since allergens are proteins, a realistic concern is the possibility of introducing new allergens.  The scientists go to great lengths to ensure they are not putting a food into the system that can cause an allergic reaction.  In fact, with GE, scientists see the possibility of removing potential allergens in the future!

Another potential concern regarding the safety of GMO’s is with antibiotic resistance.  Antibiotic resistant genes are commonly used as markers when creating GE plants, so they remain with the plant.  Most experts agree that the risk of transferring these genes to human or animal pathogens is low.

While this is not a safety issue, one negative side effect of GMO’s is the possibility for building resistance to the insecticidal gene.  As you read further, insecticides is one of the sought after benefits to GE crops.  So, if the insect doesn’t die from ingesting the insecticidal protein immediately, there is the reality that they can build a resistance to it.  For example, BT corn was not successful at killing off one targeted insect called the root-worm.  As a result, there was some survival, and now farmers are no longer able to control these insects with the BT corn that was released in 2004.

The fact is, GE crops are studied more rigorously than any other foods.  The good thing is, when studying these foods, we can look for specific concerns because we know the exact protein added.

With that said we don’t have any long-term feeding trials available.  Of course, that is normal for the food industry!  When it comes to studying the effect of the food we eat, we have difficulty obtaining sound, conclusive research.  This is related to the reality that we can’t control for diet in humans.  And when we do it’s not for very long, plus, we are extremely limited in the number of subjects we can control.  Any long term research we have is from observational studies, which are not controlled and only show a relationship, not a conclusive causation.

One trend I’m seeing is the acknowledgment that not all people react in the same way, and there has been a movement toward personalizing research.  With this idea in mind, I would challenge anyone to pay attention to how they respond to GE foods versus non-GE foods.  I can only give you what the research says, but I completely understand people’s fears about GMO’s.  And I can admit that in the past we’ve pushed man-made foods only to discover, upon further testing, that we were wrong.

For example, the initial thought with Trans Fats, is that they don’t have cholesterol, so therefore they would be better for you than saturated fats which have cholesterol.  Then we learned that cholesterol intake does not cause increase in cholesterol levels, so we concluded that while they may not be better, they certainly weren’t worse.  We defended the convenience of them, as well.  Because of these trans fats, foods that would normally be rancid have longer self lives.  What an advantage!  Now, we’ve come full circle, where we are banning them after realizing that they do contribute to chronic disease.

I’m not saying that we are wrong in the case of GMO’s.  But I am saying that I understand the desire to avoid them.



Why do we use GMO’s?

Typically the main objective of GE is to make crops resistant to pests, such as weeds, insects, and herbicides, as well as disease.  In addition, we can produce crops that are more resistant to droughts.  These traits make it better for farmers as it’s simpler, more efficient, and, in some cases, less expensive.  Now they can use less insecticides for insect resistant crops or simpler choices of herbicides which promote better weed control.

In the case of insecticides, the current insecticides that are used sit outside the seed.  Therefore, they affect any insect that comes in contact with it.  Whereas there are certain insects that are beneficial to crops, like honey bees and earthworms.  So, it is not in the best interest to kill all insects that come in contact with crops.  GE allows us to produce a protein within the plant that is insecticidal and targets a very narrow range of insects upon ingestion.  For example, BT corn has no affect on the thousands and thousands of beetle species except one – the specific type of beetle that is known to destroy the crop. In addition to the undesirable affect of insecticides on other insects, there is concern for worker safety, as they work around these chemical insecticides; not to mention the added costs of purchasing and the need for added space to store the insecticides.

They can also use GE to make foods more nutritious.  For example, “golden rice,” which has been in development for 15 years, was enhanced with beta-carotene to address the global vitamin A deficiency.  This is not on the market, yet.  Also, some soy beans are being genetically modified to increase oleic acid content and decrease polyunsaturated fat to make their fatty acid profile similar to fatty fish.

GE is also used to enhance the quality of crops.  For example, scientists can prevent bruising on potatoes and produce less of the cancer-causing agent, acrylamide, when exposed to high heat.  Also, there are genetically modified apples that will not brown when exposed to oxygen.

While all the GE has been on crops, there are GE animals that have been in the works.  For example, in November 2015, the FDA approved the production of AquaAdvantage Salmon.  This fish is genetically engineered to grow to market size faster (half the time).  These may be available on the market in 1 or 2 years and would be the first genetically modified animal available.

Some attempts to yield improved crops have failed.  For example, in 1994, the Flavr Savr Tomato was the first engineered food and was designed to remain firm for a longer time.  However, they are no longer produced because they were not financially successful.

Ultimately, GMO is used to positively impact the food supply and assist the farmers to produce better crop yields.


What is the difference in breeding versus genetically modifying crops?

First, realize that we have been genetically modifying animals and plants for desirable characteristics through selective breeding and crossbreeding of related species for thousands of years.  Development of this breeding and crossbreeding in plants really took off in the 1960’s under the work of Norman Borlaug, who is known as the “Father of the Green Revolution.”  Previous work included ways to induce genetic mutations in plants, but Borlaug was able to advance these methods which led to modern plant breeding.  Through his work as an agricultural scientist, Borlaug developed short stature wheat.  Prior to Borlaug’s work, wheat was bred to produce a lot of seeds, which made it top heavy.  As a result, the stems would droop over into the soil, where they would rot.  This resulted in significant crop loss each year.  Borlaug’s short stature wheat kept the stem from folding over, which saved the crop from rotting in the soil.   In 1970, he won the Nobel Peace Prize for his work bringing this short stature wheat to developing countries, specifically Mexico, India, and Pakistan, which is estimated to have saved as many as one billion people from starvation and death.

Now, through GMO’s, we can do in one year, what took Borlaug decades to do, by changing the gene that produces the hormone that expresses height growth.

The difference in the breeding/crossbreeding process and GMO’s, is our ability to isolate a specific gene from one species, and insert it into another.  As opposed to altering many traits simultaneously with conventional breeding, we can change one specific trait (without affecting any other properties of that plant) with GE.




How prevalent are GMO’s?

The US, Brazil, and Argentina represent 90% of the world’s produce, and over 90% of those plants are genetically modified.  India, China Canada, and Australia also grow GMO’s.  The US is the largest grower of GE crops.  In fact, as of 1-2 years ago, 95% of soybean acreage, 96% of cotton acreage, and 93% of corn acreage was genetically engineered in the US.

Here is a list of all GE crops:


  • Alfalfa (for cattle feed)
  • Canola
  • Corn
  • Cotton (cotton seed oil is commonly used in restaurant and commercial frying)
  • Hawaiian papaya
  • Soy
  • Sugar beets
  • Summer squash
  • Zucchini


Recently, certain apples and potatoes have been approved but aren’t on the market as of yet.  The four major crops include corn, soybeans, cotton, and canola.

These GE plants are used in animal feed as well as in a wide range of products from infant formula, to chips and other snack foods, to fast food, and processed foods like ketchup, drinks with high fructose corn syrup, candy, chocolate, and corn starch.

The non-GMO project is a non-profit organization committed to preserving and building a non-GMO food supply.  They estimate that as many as 80% of packaged products on the grocery store shelves contain a GE ingredient (most of these contain just one or a very small amount of GE foods).


What are the regulations for GMO’s?

There are 3 main regulatory bodies:

  1. USDA – offers the field permits and looks at the fields
  2. EPA – looks at any environmental issues
  3. FDA – looks at any potential impact on food or animal health

Both the senate and the House of Representatives passed a bill on July 29, 2016 requiring food manufacturers to label products that contain GMO’s, using a standard based on USDA control.  Prior to that bill, there were no requirements for foods to be labeled as GMO because, per the FDA, they were treated the same as the non-GMO counterparts.  The USDA has two years to determine exactly how much bioengineered substance must be present in a food for it to fall within the law.  In other words, they will  have to interpret what is considered a GMO and where to draw the line.  For example, if a soda is sweetened with high fructose corn syrup that was derived from GMO corn, but it no longer contains the gene (protein) that was modified, should it be identified on the label?  If not, many highly refined ingredients that are derived from GMO’s will escape the label law because they no longer contain the modified protein.

One major concern and the reason behind resistance to this new label law is that it will cause unsubstantiated concern against GMO’s.

At this time, it is not certain whether labels will use plain text, a symbol, or a QR code.

Keep in mind, this law will take two years to take effect.  With that said, currently, you cannot rely on label claims to always be accurate.  If you are interested in avoiding GMO’s, the safest bet for now is to look for “certified organic”.  The claim, “non-GMO” is not regulated at this time.



The bottom line with regards to GMO’s:

Ultimately, there is no reason to believe GMO’s are bad for us.  I find it puzzling that we, as a culture, love and embrace technology in every other aspect of society, but when it comes to our food, we want to resort to caveman days.  I, for one, am not afraid of GMO’s in my diet, but I completely respect and even endorse one’s attempt to incorporate more “natural” foods as a lifestyle choice.  My best advice, just like with everything else, is do the best you can to eat those whole, natural, minimally processed foods and avoid GMO’s where possible, but you don’t have to be extreme about it!


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