Modern large scale agriculture practices today often include the use of genetically modified crops. GMOs (genetically modified organisms) have genes from another species, usually a bacteria, transplanted into their DNA to achieve a new characteristic. This is done to ultimately increase production or yield by adding some other previously nonexistent quality to the organism. This is not the same as hybridizing. Hybrids are created through breeding. 

There are two primary genetic modifications widely used in agriculture today.

  1. Herbicide (Glyphosate) Tolerant (HT) – also known as “Roundup Ready”, these are crops that are genetically altered with a gene from the Agrobacterium species, to be able to tolerate high amounts of the herbicide called Glyphosate, the active ingredient in the popular product Roundup.  This herbicide can be sprayed on the crop, without killing the crop but effectively kills the pesky weeds.  Evidently, the weeds are developing a tolerance to this herbicide, because more and more of it is being used every year. Much of this glyphosate is absorbed into the plant and ends up in our food.
  2. Pest resistant – this is accomplished through the incorporation of gene from the bacteria Bacillus thuringiensis (Bt).  This gene is added to the plant DNA to make the plant make a chemical called Cry proteins. Cry proteins have long been a common ingredient in insecticides applied as a spray. This is toxic to the GI tract of insects, but appears to not negatively affect the GI tract of mammals, including humans, as it is degraded by stomach acid. It is less clear how this chemical is broken down in people who don’t produce adequate stomach acid, like people on acid blocking medication.  One benefit of Bt modified plants is that it reduces the amount of insecticide applied topically to the plant. 

More recently, a GM White Russet potato has become widely planted in the US, called the Innate Potato.  The genetic modification in this product involves a method of gene silencing called RNA interference (RNAi). This process reduces the potato’s own production of 2 chemicals, one causes the occurrence of bruising/browning and production of a chemical called asparagine, and is intended to diminish the carcinogenicity of fried potatoes. 

GMO crops are incredibly common in the United States, with at least 90% of corn, soy, cotton, canola, alfalfa, and sugar beets, being grown with genetic techniques. In fact, it’s estimated that up to 80% of foods in supermarkets contain ingredients that come from genetically modified crops.  Much of these crops are made into end products that are highly processed, like animal feed, processed cooking oils, white sugar, corn starch, or other additives.  It should also be noted that some GM seeds are now “stacked seeds” meaning they are modified to be both herbicide resistant AND pest resistant with the Bt gene. This is particularly true of Corn and Cotton. While they are deemed “safe” by the FDA and the producers of these products, there have been some notable concerns raised about their pervasive use in our diets.


One major concern has less to do with the genetic alteration itself but the reason for the alteration.  “Round-up Ready” glyphosate-tolerant plants allow for the heavy use of glyphosate, and this chemical raises some serious concerns.  Glyphosate has been shown to act like a highly targeted antibiotic in the guts of animals and people. Unfortunately, it targets our beneficial bacteria—the microbes that help with digestion, detoxification, hormonal balance, immune system and more. It has no effect on pathogenic bacteria like E. Coli and botulism. The prevalence of glyphosate in our diet has been associated with increased rates of Celiac Disease and other gluten sensitivities, disrupt the gut microbiome, causes inflammation in the epithelium of the intestines, interferes with intestinal detoxification pathways, and contributes to nutrient deficiency. An increased risk to non-Hodgkin’s lymphoma, has also been implicated in glyphosate exposure.  Glyphosate residue on food may come less from its use as an herbicide, which is often sprayed when the field is fallow or earlier in the growth cycle. But some farmer use glyphosate as desiccant, though it is not registered as such, right before harvest to dry out the crop and make it faster to harvest. This leads to much higher amounts of residue left on the food product than would otherwise be used during normal use.  This is especially common in wheat, oats, barley, sugar cane and beans.

Combined Bt and HT corn and cotton are the most commonly grown varieties of “stacked seeds”, which means multiple genetic mutations.  Bt gene modification alone has been regarded as safe for human consumption however, there are some additional concerns for the corn varieties with stacked genes. Some studies have shown that Rat (mammalian) intestinal tracts fed a diet with stacked Bt/HT corn shows damage to the epithelium tight junctions, increase swelling of glands in the stomach with some increased signs of dysplasia, pre-cancerous cells. It is unclear if this could be attributed to one of the genes, or if it points to the amount of glyphosate residue that may have been left on the feed.

The Genetically Modified Potato – The development of this product may have been well-intentioned, the lead engineer for this project, Caius Rommens, evidently has developed some concerned about the farther reaching consequences of the genetic modifications. The potatoes have been altered with a silencing gene, which makes the potato produce less of an unwanted chemical. In the case, it is effective at reducing polyphenol oxidase and asparagine, which ultimate lowers the amount of acrylamide in french fries. It has the unintended consequence of increasing the amount of other potential toxins, like Alpha-aminoadipate, which is a neurotoxin, and chaconine-malonyl which has been insufficiently studied to know of possible risks. While reducing the chemical in potatoes that has the potential to turn french fries carcinogenic can be noble, he argues that he has yet to find a study that actually demonstrates carcinogenicity of regular fries.  He is quoted as saying regarding the silencing gene: “Silencing is not gene-specific. Any gene with a similar structure to the silencing construct may be silenced as well. It is even possible that the silencing that takes place inside the GM potatoes affects the genes of animals eating these GM potatoes. I am most concerned about bees that don’t eat GM potatoes but may use GM potato pollen to feed their larvae. Based on my assessment of the literature, it appears that the silencing constructs are active in pollen.”

His primary concern about genetic engineering is that the absence of unintentional effects can never be guaranteed.

How to minimize exposure to GMO foods or glyphosate residue?

It may not be practical to completely avoid exposure, however, it can be helpful to consider buying the following foods organic, as they will not be genetically modified and will also have minimal glyphosate residue. If organic is not possible, you can also look for the Non-GMO label on products sold at the store. For example, you can find this label on Corn products like corn chips and popcorn that is not organic, but still Non-GMO. When buying cooking oil, avoid non-organic soy, corn, or canola oil.  Minimize use of corn starch and white sugar.

Buy Organic – 

  • Corn (commonly genetically modified)
  • Soy (commonly genetically modified)
  • Canola (commonly genetically modified)
  • Sugar beets (commonly genetically modified)
  • White Russet Potatoes (commonly genetically modified)
  • Wheat (due to possible heavy glyphosate residue)
  • Oat (due to possible heavy glyphosate residue)
  • Dried Beans (due to possible heavy glyphosate residue)
  • Sugar cane  (due to possible heavy glyphosate residue)