Genetically Modified Organisms, or GMOs — a term often heard, sometimes feared, and rarely well understood. Used in agriculture, medicine, and even scientific research, GMOs spark both hope and controversy. In this article, we offer a clear, unbiased overview to help you better understand what they are, where they come from, how they’re used, and what science says about their effects on the environment and health.
What Is a GMO?
A genetically modified organism (GMO) is a living being — a plant, animal, or microbe — whose genetic material has been altered in a way that does not occur naturally, using genetic engineering techniques. This means one or more genes have been added, removed, or modified to give the organism specific traits.
Examples:
- A plant engineered to resist herbicides (such as Roundup Ready soybeans)
- A variety of corn that produces its own natural insecticide (Bt corn)
- A tomato designed to better withstand transport and storage
Origins and History of GMOs
The first experiments in genetic modification date back to the 1970s, but it wasn’t until the 1990s that GMOs entered commercial agriculture.
In 1994, the Flavr Savr tomato became the first GMO food product sold in the United States. Since then, GMO crops like corn, cotton, soybeans, and canola have spread across several countries, including the United States, Brazil, India, and Argentina.
GMOs are also used in laboratories to produce insulin, vaccines, enzymes, and to study certain genetic diseases.
What Are the Environmental and Health Impacts of GMOs?
Environmental Impact: Between Efficiency and Risk
According to data from the FAO (Food and Agriculture Organization of the United Nations) and various published studies, GMOs have, in some cases, contributed to:
- a reduction in insecticide use,
- improved crop yields,
- fewer losses due to disease or pests.
Moreover, the FAO acknowledges that biotechnologies — including GMOs — can support food security and sustainable development, provided they are used responsibly, with thorough risk assessments, and in ways that respect the needs of developing countries.
Source: Agricultural Biotechnologies: FAO Statement on Biotechnology
However, several ecological risks have also been documented:
- the emergence of “superweeds” resistant to herbicides,
- a decline in local biodiversity,
- genetic pollution (crossbreeding with wild plants),
- farmers’ dependency on patented seeds.
Health Impacts: What Science Says
Numerous studies have been conducted to assess the potential toxicity and long-term effects of GMOs. Major health agencies — including the WHO, EFSA, and Health Canada — conclude that GMOs currently approved for consumption are safe for human health, provided they have passed regulatory assessments.
A foundational example is the first genetically modified tomato evaluated in Canada — the Flavr Savr. In the late 1990s, Health Canada assessed its safety, focusing on nutritional composition, potential toxicity, allergens, and genetic stability. The conclusion: the tomato posed no greater risk to human health than conventional tomatoes.
Likewise, according to France’s Ministry for the Ecological Transition, no scientifically proven adverse health effects have been established for authorized GMOs. However, ongoing monitoring is maintained, especially concerning indirect impacts from agricultural use, such as herbicide residues.
However, some independent researchers call for more long-term studies and increased vigilance, particularly concerning the effects of associated herbicides such as glyphosate. The debate remains open, even though the scientific consensus generally considers GMOs safe based on current knowledge.
Global Regulations
Regulations vary widely from country to country:
- European Union: Very strict. Mandatory labeling, and only a few GMO crops are approved (mainly one type of corn).
- United States: Much more lenient. GMOs are widely cultivated, and labeling was not mandatory until recently.
- Canada: GMOs are allowed following scientific assessment. Labeling is not required.
- Brazil, India, Argentina: Major GMO producers for export-oriented agriculture.
- Africa: Adoption varies greatly depending on the country, often limited by socioeconomic and political considerations.
- Japan: Imports GMOs but permits very few domestic GMO crops.
Diverging Opinions: Controversies and Limitations
While many health agencies confirm the safety of currently approved GMOs, some researchers highlight significant limitations in existing evaluations.
- A controversial study conducted in 2012 by French researcher Gilles-Éric Séralini — published and later retracted by Food and Chemical Toxicology — suggested a link between long-term consumption of NK603 GMO corn and tumor development in rats. Though criticized for its methodology, the study reignited debate over the long-term effects of GMOs.
- Researchers continue to call for more independent, multigenerational studies, as many current evaluations are funded or overseen by the companies producing the GMOs.
Environment: A Delicate Balance
One of the most controversial cases involves the use of glyphosate, an herbicide heavily used alongside certain GMO crops (such as Roundup Ready soy or corn).
According to Volume 112 of the monographs from the International Agency for Research on Cancer (IARC), published in 2015, glyphosate was classified as “probably carcinogenic to humans” (Group 2A), based on limited evidence in humans and sufficient evidence in animals.
This classification sparked intense scientific and legal controversy — particularly in the United States, where numerous lawsuits have been filed.
While other agencies such as EFSA (European Food Safety Authority) and Health Canada do not confirm this risk at authorized exposure levels, the debate remains open — highlighting the complexity of evaluating the indirect impacts of GMOs.
Even though GMOs can sometimes reduce the need for plant protection treatments, their intensive use has also led to well-documented side effects:
- Repeated use of herbicides on herbicide-resistant GMO crops (such as those treated with glyphosate) has resulted in the emergence of herbicide-resistant weeds, requiring increased use of chemicals or stronger herbicides.
- Large-scale cultivation of only a few GMO varieties contributes to the erosion of genetic diversity, potentially making agricultural systems more vulnerable to disease and climate change.
- There is a risk of genetic pollution when modified genes spread to wild plants through crossbreeding, unpredictably altering ecosystems.
These concerns do not mean that all GMOs are dangerous, but rather that careful, transparent, and balanced management is essential to avoid unforeseen long-term consequences.
Scientific Data and Evidence
🌍 Global Adoption
17 M
farmers in 29 countries.
As of 2019, more than 17 million farmers were growing genetically modified crops.
These crops are especially widespread in the United States, Brazil, India, Argentina, and Canada, where they contribute to higher agricultural yields and reduced use of chemical inputs.
🐛 Fewer Pesticides
−37 %
average global reduction in pesticide use.
A 2014 meta-analysis published in PLOS ONE, based on 147 studies, found that the adoption of GMO crops led to an average 37% decrease in pesticide use — particularly due to insect-resistant plants like Bt corn.
Source: A Meta-Analysis of the Impacts of Genetically Modified Crops | PLOS One
✅ Health Safety
50+ years
of scientific research with no proven health risk.
According to the WHO, commercially available GMOs have been rigorously evaluated and present no known health risks.
A 2016 report by the U.S. National Academies of Sciences also confirmed the lack of evidence for any harm to human health, while recommending ongoing monitoring of environmental and social impacts.
Source: National Academies – Genetically Engineered Crops: Experiences and Prospects- New Report
🤔 Public Perception
48 %
of citizens believe GMOs are dangerous.
Public opinion remains divided. A 2020 survey conducted by the Pew Research Center across 20 countries found that, on average, 48% of respondents consider GMOs unsafe to eat, compared to only 13% who see them as safe.
This gap highlights the ongoing contrast between scientific understanding and public perception.
Source: Pew Research Center – On Genetically Modified Foods, Widespread Skepticism in 20 Publics
GMOs Today and Tomorrow
How Are GMOs Used Today?
GMOs are currently found in:
- Agriculture (corn, soy, cotton, canola, papaya, etc.)
- Medicine (insulin, hormones, mRNA vaccines)
- Research (animal models, gene therapy)
- Industry (food enzymes, detergents, biofuels)
Some next-generation projects aim to create plants that are more drought-tolerant or can grow in poor soil, or even trees that absorb more CO₂. Progress is also being made with new gene-editing techniques like CRISPR-Cas9.
What Does the Future Hold for GMOs?
The future of GMOs may unfold on several fronts:
- Innovation (second-generation GMOs, CRISPR, precision agriculture)
- Transparency (traceability, clear labeling)
- Social acceptance (ethics, food sovereignty)
- Global regulation (common standards, patent policies)
Conclusion
One thing is clear: biotechnology is poised to play an increasingly important role in addressing tomorrow’s food and climate challenges. The debate shouldn’t divide — it should inform, allowing everyone to make educated choices.