In this blog post, we’ll take a calm, objective look at both the benefits of GMOs and the practical, long-term risks—such as allergies, gene transfer, interspecies hybridization, and superweeds—using concrete examples and evidence.
What Are GMOs?
Genetically Modified Organisms (GMOs) are organisms in which specific genes have been altered in ways that do not occur naturally, or into which genes from other organisms have been inserted. Through this method, often called “modern biotechnology” or “genetic engineering,” individual genes can be transferred even between unrelated species. This technology is widely used in the development and cultivation of food crops, aiming to artificially alter crop characteristics to achieve various goals such as pest resistance, herbicide tolerance, and virus resistance.
Advantages of GMOs
The original purpose of developing GMOs was to protect crops and improve productivity. For example, introducing the toxin gene produced by the soil microorganism Bacillus thuringiensis (Bt) into crops confers resistance to insects, thereby reducing the need for insecticides. Additionally, introducing genes that confer resistance to herbicides reduces crop damage when specific herbicides are used, allowing for a reduction in the total amount of herbicides applied. Introducing genes from viruses that cause plant diseases can confer virus resistance, thereby reducing damage from those diseases and increasing crop yields. For instance, there are reports of slight yield increases in some cases where genetically modified crops were introduced at a certain rate. Thus, reduced use of pesticides and herbicides and increased crop yields are cited as the main advantages of GMOs.
Major Issues with GMOs
The most critical concern in the debate over GMOs is the potential for harm, which has not yet been fully elucidated. In particular, risks directly related to humans must be addressed with the utmost seriousness. In this regard, three major issues can be identified: allergenicity, gene transfer, and outcrossing.
First is the issue of allergenicity. Unless it is sufficiently proven that the proteins produced by the genes inserted into crops do not cause allergic reactions, the introduction of such genes must be approached with caution. Realistically, since most traditional foods are not strictly tested for allergenicity, it is difficult to completely rule out the risk of allergies resulting from the introduction of new genes.
Second is the issue of gene transfer. Concerns have been raised regarding the possibility that DNA derived from GMOs may not be broken down during the digestive process and could be transferred to human somatic cells or gut bacteria, causing genetic changes. In particular, if genes such as antibiotic resistance genes are transferred to other organisms, this could pose serious public health risks. Although the likelihood of such transfer is low, there are recommendations to avoid the use of antibiotic resistance genes in consideration of the potential risks.
Third, there is the possibility of outcrossing. If GMO genes transfer to existing crops or wild species, it could affect food safety and the local ecosystem. In fact, there have been reports of trace amounts of genes from GMO corn developed for animal feed being detected in corn products intended for human consumption.
Additional Issues and Long-Term Safety
In addition to the issues mentioned above, GMOs may carry several additional risks. A prime example is the emergence of “superweeds.” If herbicide-resistant varieties are widely cultivated, the resistance genes can transfer to wild weeds, leading to the emergence of weeds resistant to herbicides.
In the United States, within a few years of the widespread adoption of crops resistant to the herbicide glyphosate, the number of resistant weeds increased, forcing farmers to change their herbicide strategies.
The rise of superweeds not only negatively impacts crop yields but can also lead to a vicious cycle where farmers are forced to use stronger or more environmentally and health-hazardous herbicides. For example, chemicals such as 2,4-D have been cited as causing various problems for human health and the environment. The use of stronger herbicides can lead to unintended damage (such as crop damage in adjacent fields and threats to endangered species) and ultimately raises concerns that it will once again give rise to resistant weeds.
Another key issue is long-term safety. While some studies have suggested a link between GMO consumption and health problems, these studies have also faced criticism for methodological limitations. A 2012 animal study reported an increased risk of tumor development in rats fed genetically modified corn, but it sparked controversy in the academic community due to issues with the study design and interpretation. However, this debate has highlighted the fact that GMO safety assessments have largely focused on short-term periods (e.g., within 90 days), and systematic studies on long-term exposure are relatively scarce. Consequently, there has been a growing call for rigorous, long-term toxicological and epidemiological studies.
These issues suggest that, regardless of the potential inherent in GMO technology itself, the level of risk depends on how strictly the regulatory, evaluation, and management systems are operated. The author believes that a cautious approach to GMOs is necessary due to current uncertainties and potential hazards. Long-term studies to verify safety, restraint in the use of antibiotic resistance genes, cultivation management to prevent gene flow, and standardized risk assessment procedures must be implemented in parallel.
In conclusion, while GMOs offer clear advantages, they also carry unresolved risks and potential harm. If we are to reap the technological benefits, they must be accompanied by corresponding rigorous safety reviews, transparent regulation, and long-term investment in research.
Monsanto’s History and Social Impact
Monsanto, headquartered in St. Louis, began as a chemical company in 1901 and later transformed into a biotechnology firm. It holds a vast number of patents related to genetically modified foods worldwide and has expanded its international influence through the distribution and sale of genetically modified seeds.
However, behind Monsanto’s growth lie controversial products. PCBs, Agent Orange used in the Vietnam War, and growth hormones developed to increase milk production in livestock are often cited as past issues. These historical examples serve as the backdrop for growing social distrust of the company’s image and biotechnology.
Some express concern that Monsanto could use seed patents to make farmers dependent on its seed supply chain. One critical analysis argues that if Monsanto exercises its intellectual property rights, farmers will become dependent on a single supplier and ultimately be bound by a royalty payment structure. At the same time, there is a view that the flow of personnel between high-ranking government officials and the company, lobbying activities, and the way authoritative scientific media place excessive trust in experimental results of unclear origin all serve as factors that maintain the company’s influence.
Environmental and Health Concerns Raised by GMOs and Conclusions
GMOs are closely intertwined with economic, social, and political issues. While a clear advantage is their role in supplementing food production, the reality that the technology has not yet been sufficiently adopted in some developing countries where its introduction is urgently needed is also pointed out as a problem. The fact that the benefits of the technology are not distributed equitably is a significant social issue.
Environmental concerns continue to grow.
These include potential adverse effects on beneficial insects, the emergence of herbicide-resistant weeds (so-called “superweeds”), the possibility of new outbreaks of unintended crop pathogens or pests, and the transfer of herbicide-resistant genes to other plants. While these issues are being actively researched both in the field and in laboratories, the risks of future occurrences may increase.
Furthermore, since genetically modified foods are created by inserting different genes in various ways, it is important to note that the safety of each product must be evaluated on a case-by-case basis. In other words, it is difficult to generalize by evaluating all GMOs at once using the same criteria. International organizations, such as the World Health Organization, also recommend that the safety of genetically modified foods be reviewed on a case-by-case basis.
Given the current situation—where research on long-term human health effects remains insufficient and unresolved environmental and social issues persist—it is difficult to unconditionally endorse GMOs. Therefore, deeper consideration, transparent regulation, and sufficient scientific verification must precede the technological and commercial expansion of GMOs.
