The Risk of GMO’s

A couple weeks ago I published a newsletter that covered just some of the reasons why a farmer might choose to plant GMO crops. After just two decades, many farmers around the world have adopted the use of GMO crops while consumers often look to avoid these changes to their family’s food supplies. In this article I examine why many of us skeptically look at GMO crops. Should they be part of our food supply?

Providing sufficient evidence to show a statement true is generally much more challenging than showing it false. In order to show it’s false, one must simply come up with a counter example. To show it’s true, one must find a thorough and fundamental justification, and generally must accompany the explanation with a copious amount of data to back up the claim.

Take the statement “food product made from this GM product has no adverse health effects”. In order to prove this statement false, one need only find a single example where GM food had definitive adverse health effects (however, showing that an adverse health effect was the result of GM food as opposed to some unobserved variable is a challenge unto itself). For GM products available on the marketplace, such an example has to my knowledge not yet been published. However, lack of a counterexample is not enough to prove the statement true. In order to show such a statement true, a robust theoretical framework justifying the safety must accompany vast amounts of data which shows no adverse health effects. This has also not yet been accomplished.

Thus, given the information currently publicly available, it is not possible to definitively assess the safety of GM food products. The relatively few feeding studies conducted on rats and chickens were conducted on small samples, often overweighting the control group (the group fed non-GMO feed). Additionally, many feeding studies were merely 30 days long. Most studies find no significant difference between the GMO fed treatment group and non-GMO control group. Those that do find some significant biological difference (such as weights, appearance of organs, blood samples, etc.) are often unable to determine the seriousness of this difference, and whether it constitutes an adverse health effect. Of note is the fact that the studies summarized above do not include any safety assessment studies conducted by the corporations who sell GM seeds, as such studies are generally considered proprietary.

Though no adverse health effects have been definitively shown, there are several hypothesized effects. These include the unintended creation of an allergen or toxin due to the insertion of a new gene. With enough feeding experiments, we should eventually be able to test these hypotheses. The publication of currently proprietary industry experiments would be extremely helpful to this end. The more complicated issue is weighing the ecological risks of GMO’s.

GMO’s have been hypothesized to have potentially severe ecological effects. These hypotheses are reminiscent of the ways that mankind has affected ecology in the past, notably the introduction of invasive species. For example, the introduction by Europeans of mice and bunnies into the Australian ecosystem had significant impacts on the ecosystem. Without naturally present predators these quickly multiplying species reached staggering populations and are responsible for several fortunes worth of agricultural losses as they ate and continue to eat farmers’ grain before it can be sold.

Nobody predicted that a few bunnies shipped from Europe and a few stowaway mice would eventually lead to such a great economic loss. GMO’s are generally less understood than naturally occurring creatures, and thus even more unpredictable. For example, one early use of genetic engineering involved making corn with male sterility. Male sterility reduces the labor required to exercise controlled breeding. The gene inserted to ensure male sterility also had the unintended effect of making the corn particularly susceptible to a fungal pathogen. Less than two decades after this strain of corn entered commercial use, it was devastated by the fungal pathogen and the strain of corn made useless.

Not only did nobody anticipate this consequence, but even with hind sight it’s difficult to determine how they would’ve anticipated it. This is perhaps the biggest risk of GMO’s. How will a GM crop interact with the plethora of organisms in the ecosystem to which it’s introduced? Will GM crops breed with wild varieties and thus spread themselves off of agricultural land? If so, what are the consequences? These questions are not only largely unanswered, but unanswerable prior to commercialization. One can not test how a GM crop interacts with an ecosystem without introducing it to the ecosystem, and if one is going to introduce it to an ecosystem they might as well profit by it.

GMO’s are widely used because their benefits are known and documented, whereas the risks are largely unknown and too often assumed to be nonexistent. There is no definitive evidence that GMO’s are consistently harmful to our health or the environment, but at the same time there is so little evidence. Continued risk studies should be conducted at increasing scales, with both larger sample sizes and longer experimental periods. Once enough data has been accumulated, we should be able to determine with great (but not perfect) confidence whether a particular GMO is safe for consumption. The environmental concerns are trickier to address.

Perhaps unfortunately, regardless of potential risks, GMO’s are here to stay for the foreseeable future. Farmers across the globe see GM crops as a solution to numerous agricultural problems from providing adequate nutrition to those with very limited budgets, to reducing cases of farmer pesticide related poisonings. Whether or not you want to feed GMO products to your family is a different matter, and entirely up to you. There are plenty of farmers in This Old Farm’s alliance that plant non-GMO crops and feed non-GMO feed to their livestock. Whatever your choice, This Old Farm will ensure you receive a product which meets your standards.

Conner Smith


Pryme, I., Lembecke, R. In Vivo Studies on Possible Health Consequences of Genetically Modified Food and Feed – With Particular Regard to Ingredients Consisting of Genetically Modified Plant Materials. 2003. Nutrition and Health, 17, 1-8

Pusztai, A., Bardocz, S. Potential Health Effects of Foods Derived from Genetically Modified (GM) plants – What are the Issues?. 2007. Biosafety First: Holistic Approaches to Risk and Uncertainty in Genetic Engineering and Genetically Modified Organisms. Chapter 14.

Williamson, M. Environmental Risks from the Release of Genetically Modified Organisms (GMO’s) – The Need for Molecular Ecology. 1992. Molecular Ecology, 1, 3-8

One Comment

  1. Chris Calabria

    I won’t stand in front of a discharged gun, or sleep with a prostitute thinking if I stand on one leg ….I’ll be safe.
    We DON’T know, what we don’t know….
    Once we do the wrong thing, it won’t matter.
    I’m tired of the arguments concerning anything science has up their sleeve, they’ve been right before, but wrong soooo many.


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