GMOs: Scientific or Social Uncertainty?

Kate Sedivy-HaleyBy Katharine Sedivy-Haley, PhD Candidate, Hancock Lab

Genetic engineering is the process of altering the blueprints of an organism in order to effect some desired change. Since its discovery in the 1970s, this technology has been used to advance research, industry, medicine, and agriculture. However, using genetic modification to engineer the food we eat has been an ongoing contention. Biological systems are complex and interconnected, and some fear that genetic modification may cause significant ripple effects impacting the health of consumers or the surrounding environment. For example, if corn is engineered to produce a natural insecticide, what will happen to that insecticide? Could it harm people eating the corn, or start an evolutionary arms race with pests? For decades, scientists, consumers, and regulators have attempted to assess and respond to these risks.

The majority of scientists believe1 that genetically modified organisms (GMOs) are safe. Genetic engineering is at least as predictable as “conventional” techniques2, which, since the 1930s, have included the hybridization of different plants and the use of chemicals or radiation to introduce random genetic changes in the hope that some of the resulting plants will have desirable traits. Studies have repeatedly failed to identify any adverse health consequences in GMOs, and GM crops have become commonplace in North America without any apparent ill effects on biodiversity or the health of humans or livestock3,4.

However, a vocal minority of scientists say that the issue of safety is still unresolved5. These dissenters cite studies of too short duration or with too few subjects to reveal potentially subtle differences in health outcomes. The distribution of GMO products is not well tracked, making it difficult to assess their effects on humans. Ecological effects are also difficult to measure, and may vary with local environment and regulations. For example, the effects of herbicide-resistant GM crops depend on the impact of the new herbicide compared to alternative herbicides used in a given country6. Ecologists express more uncertainty regarding the safety of GMOs than researchers studying other issues such as food safety, where the scientific debate is not so much about whether GMOs are dangerous, as it is about how confident we are that GMOs are safe5.

The consumer perspective is more skeptical of GMOs than the general scientific community. This skepticism may partly be due to a fuzzy understanding of the technology, or viewing DNA as an ‘essence’ of living organisms that shouldn’t be tinkered with7. However, consumer distrust is not just targeted at the technology behind GMOs, but also at the corporations that seek to profit from them. GMO patents – and Monsanto’s aggressive defense of these patents – have resulted in unprecedented corporate ownership of living organisms. Many consumers are concerned about how well we can trust the giants that produce our food – GMO or otherwise – and the institutions that regulate it.

Multiple government institutions have responded to public discomfort with GMOs by requiring stringent safety assessments for each new organism. In theory, this is a reasonable response to the varied possible characteristics of GM crops. In practice however, only crops backed by a strong commercial interest can make it over costly regulation hurdles while crops with primarily humanitarian benefits struggle to fund the necessary safety trials. For example, Vitamin A-enriched ‘Golden Rice’ was predicted to save millions of lives by reducing vitamin A deficiency in Africa and Asia but has yet to make it to market8. This imbalance perpetuates the public perception that GMO development is dominated by large corporations and unlikely to provide significant public benefit. This belief promotes continued opposition to GMOs, further undermining the ability of this technology to benefit society.

Despite these problems, it is important to recognize that GMOs do have a wide range of potential benefits6. Plants that are higher yielding, more nutritious, and more resistant to changing conditions could be vital in addressing food security in the face of climate change. Replacing pesticide use with naturally pest-resistant crops could have environmental benefits if properly managed. These rewards are perhaps too significant to leave on the table, but our current system of relying on private corporations to bring GMOs to market has not furthered the best usage of this technology. Additional studies would improve our understanding of the long-term effects of GMOs in biological and ecological systems. However, it is essential that we address the human systems of food production in order to realize public benefits while managing public risks.


  1. Funk, C. & Rainie, L. Public and Scientists’ Views on Science and Society. (2015). Available at: http://www.pewinternet.org/2015/01/29/public-and-scientists-views-on-science-and-society/. (Accessed: 2nd April 2018)
  2. Herman, R. A. & Price, W. D. Unintended Compositional Changes in Genetically Modified (GM) Crops: 20 Years of Research. J. Agric. Food Chem. 61, 11695–11701 (2013).
  3. Van Eenennaam, A. L. & Young, A. E. Prevalence and impacts of genetically engineered feedstuffs on livestock populations1. J. Anim. Sci. 92, 4255–4278 (2014).
  4. Nicolia, A., Manzo, A., Veronesi, F. & Rosellini, D. An overview of the last 10 years of genetically engineered crop safety research. Crit Rev Biotechnol 34, 1549–7801 (2014).
  5. Hilbeck, A. et al. No scientific consensus on GMO safety. Environ. Sci. Eur. 27, 4 (2015).
  6. Barrows, G., Sexton, S. & Zilberman, D. Agricultural Biotechnology: The Promise and Prospects of Genetically Modified Crops. J. Econ. Perspect. 28, 99–120 (2014).
  7. Blancke, S., Van Breusegem, F., De Jaeger, G., Braeckman, J. & Van Montagu, M. Fatal attraction: the intuitive appeal of GMO opposition. Trends Plant Sci. 20, 414–418 (2015).
  8. Enserink, M. Tough Lessons from Golden Rice. Science (80-. ). 320, 468–471 (2008).