I published a previous commentary to introduce the conflict between those who view Genetically Modified Organisms (GMOs) as a danger to the environment and people and supporters who see them as the solution in how to feed an expanding human population. There are several wonderful web sites that discuss the issues in detail, and one of my favorites is one titled “Genetically Modified Foods:  Harmful or Helpful?” by Deborah B. Whitman. I intend to summarize what she and others say about why they may be harmful in this commentary and save the positive side as future material.

Plants are modified in the laboratory by gene transfer to gain several advantages in resistance to pests, herbicides, drought, and to add crop yields and nutritional value. However, the resistance to pests is believed by some to have unintended consequences. A study published in Nature warns that pollen from corn genetically modified to provide resistance to pest has caused high mortality in monarch butterfly caterpillars. The pollen from the corn blows onto milkweed plants and the caterpillars “…could eat the pollen and perish.” There are some questions about the validity of the study, and initial evaluation by governmental agencies suggests the study might have been flawed. However, there is no question that the toxins produced in the genetically modified corn will “…kill many species of insect larvae indiscriminately; it is not possible to design a …toxin that would only kill crop-damaging pests and remain harmless to other insects.” I do find it odd that one criticism is that pests could become resistant to the genetically modified crop toxins just as some have developed resistance to other pesticides. I would have thought opponents to pesticides would welcome a new approach.

Another concern is that weeds will cross-breed with plants engineered for herbicide tolerance to make “superweeds.” The genes could cross over into non-modified crops planted next to GMO fields. There is no doubt that pollen from GMO fields move to surrounding areas because Monsanto has filed lawsuits against famers who have fields next to the GMO fields.

The issue that I predict will be the most difficult to resolve is the fear of unknown effects on human health. Answers.com says that opponents of GMOs have cleverly invented the term “Frankenfoods,” although I tend to be turned off by invention of terms that are designed to cause people to react in an emotional rather than thoughtful manner.

There is a disputed study that claims there were appreciable differences in the intestines of rats fed GMO potatoes and rats fed unmodified potatoes. The test results should not have been a surprise. The scientists creating the potatoes used a substance known to be toxic to test their methodology and did not intend the potatoes to be used for human or animal consumption.

The question of allergenicity is troubling. Many people have life-threatening allergies to peanuts and other foods. There is the concern that introducing genes into plants will create allergens that could cause reactions in susceptible people.  

I intend to do a commentary next week on the positives associated with them, and I predict that people who oppose GMOs will want to consider that position.