The biotech industry has been manipulating the genetic material of living organisms and crops using CRISPR (clustered regularly interspaced short palindromic repeats) gene editing technology, resulting in changes in flavor profiles, longer shelf life, and increased resistance to specific pathogens, but with unknown health consequences.1
Until now, these genetic modifications have been carried out in controlled laboratory settings. However, a disturbing new development is on the horizon: new pesticides designed to edit genes, which are touted as being “greener” than chemical pesticides, could soon be available.2
A team of scientists recently expressed concern about the potential consequences of releasing this product into an open environment, where it may affect not only its intended targets, but also a wide range of non-target organisms, possibly causing far-reaching ecological destruction. And topping the list of potential collateral damage is us, humans.3
How does CRISPR gene editing work?
The principle behind CRISPR gene editing technology, considered a revolutionary tool in biotechnology, comes from nature itself. Essentially, CRISPR is a defense mechanism present in bacteria and archaea, which helps protect these microorganisms from viral pathogens. Scientists adapted it for use in other organisms, turning it into a gene editing tool.4
The CRISPR system relies on two main components: the Cas9 protein and a guide RNA (gRNA). The Cas9 protein acts as a molecular scissor that can cut DNA at specific locations, while the gRNA is designed to match and bind to a particular DNA sequence, directing the Cas9 protein to the precise location where the cut is needed.5
Once the Cas9 protein reaches the target site, it produces a double-strand break in the DNA. The cell’s natural repair mechanisms kick in to repair the break. This repair process can be harnessed to introduce new genetic material or make modifications, such as inserting new genes, deleting existing ones, or modifying genes to achieve desired traits or correct genetic defects. However, multiple studies have shown that this technology carries numerous potential risks.6
A recent study reveals unintended side effects of CRISPR-edited pesticides
The group of scientists who sounded the alarm about gene-editing pesticides presented their findings in a study published in the journal Ecotoxicology and Environmental Safety.7 Using a combination of computational tools and in silico models, they simulated the potential impact of CRISPR-edited pesticides on a variety of non-target organisms (NTOs).
“CRISPR/Cas9, a powerful genetic engineering tool widely adopted in agriculture, is capable of introducing new traits into plants on a large scale and without conventional breeding methods… Our goal was to evaluate potential activity in organisms that might be exposed to genome editing in uncontrolled environments,” The authors wrote.
They began by simulating three plausible scenarios for the application of these pesticides: irrigation, spraying, and fertilization. To identify potential unintended consequences, they focused on mRNAs they designed to act on pest-specific genes. They investigated whether they could also interact with unintended genes in unintended species.
The study covered 18 species commonly found in agricultural settings, including crops like corn and soybeans, livestock like cows and chickens, pollinators like bees, and soil organisms like earthworms and fungi. They also identified three pests that are likely to be targeted by the use of these new pesticides: the western corn rootworm, the red flour beetle, and the fungus Sclerotinia sclerotium. According to their findings:8
“Whether NTOs are desired or not, the consequences of modifying them remain unpredictable due to the large number of unintended modifications. gRNA activity was observed in 12 of the 18 NTO species investigated in this study.
These hybridization sites revealed genes with functions in several annotated metabolisms, from central nervous system morphogenesis in the honeybee to several cancer-related pathways and hormonal metabolism in humans. In total, 155 metabolic pathways were enriched for the three gRNA scenarios in the 12 species with the most matches in the human genome.”
Unknown consequences could affect the environment and human health
In short, the researchers found that mRNAs from the gene-modifying pesticides affected 12 of the 18 NTOs, leading to potentially unpredictable health consequences due to unintended genetic changes. These unintended effects were observed in human genes involved in metabolic processes, including cancer and hormone regulation. In total, 155 metabolic pathways were altered in these 12 species, and most of these effects occurred in human genes.9
In addition to potential risks to human health, the authors warned that even small changes caused by gene-editing pesticides in the behavior of key ecosystem species can have large ripple effects on the environment.
For example, earthworms play a crucial role in grasslands, helping cycle nutrients, improve soil structure, and regulate water. Even a small decrease in earthworm activity due to repeated exposure to gene-modifying chemicals can significantly impact soil health and, consequently, land productivity.
The authors argue that these technologies should be considered as potential emerging environmental contaminants, given their ability to affect a variety of organisms when released into the environment. They also call for a more comprehensive risk assessment of gene-editing technologies used outside of controlled, closed laboratory environments.10
Unexpected effects are not new in CRISPR-edited organisms
There have been many cases where a genetically modified (GM) crop has unexpectedly shown toxic or allergenic properties that its conventional counterparts did not exhibit. The reality is that researchers have limited knowledge of the possible side effects that DNA manipulation can produce, as its results are highly unpredictable.
As shown in the featured study, even CRISPR, despite being touted as more precise than other genetic engineering techniques, causes unintended effects. A study published in The CRISPR Journal11 corroborated these concerns, revealing that when the CRISPR tool produces a double-strand break in DNA at the target site, it can trigger a variety of genetic outcomes, including small insertions or deletions of DNA bases and large-scale rearrangements of the genome.
CRISPR technology has also been explored to modify T cells in adoptive T cell therapy. However, a study published in Nucleic Acids Research12 notes that while it is intended to target specific genes, it also inadvertently generates unwanted structural variations in the genome. These include chromosomal translocations, where segments of chromosomes are rearranged, as well as large deletions. The authors concluded:
“Our findings raise concerns about the safety of CRISPR/Cas9-edited T cell-mediated immunotherapy. Persistent SVs could be a problem for CRISPR/Cas9-edited TCR (T cell receptor) T cells or similar CAR (chimeric antigen receptor) T cells, as these SV-containing cells may acquire more mutations during further clonal expansion.”13
In addition, researchers at Boston Children’s Hospital have found that using CRISPR in human cell lines can lead to significant DNA rearrangements, which could increase the risk of cancer. These alterations were observed in up to 6% of cases.14
In my previous articles, I have also discussed the implications of CRISPR-edited green salads,15 Insects16 and even babies.17 I encourage you to delve deeper into these issues to understand the profound and potentially dangerous consequences of this technology for our environment and our future.
What does the future hold for gene-editing pesticides?
As if conventional pesticides were not already a major concern for human health and the environment, we could soon be faced with the challenges posed by gene-edited pesticides as well. While this technology promises benefits such as reduced environmental impact, the reality presented by the study presented reveals a more worrying reality.
We could be facing a future in which the very genetic makeup of our ecosystem could be inadvertently altered, from soil microorganisms and pollinators to crops, livestock, and humans. The rapid development of this technology is outpacing our understanding of its long-term effects, essentially turning our environment and food supply into a vast, uncontrolled experiment.
The future of agriculture doesn’t have to be a choice between harmful chemical pesticides and unpredictable gene-editing technologies. Instead, we should invest in truly sustainable and regenerative farming practices that work with nature, not against it.
Regenerative agriculture eliminates the use of pesticides by focusing on soil health and biodiversity. It employs techniques such as crop rotation and integrated pest management to create balanced ecosystems where natural predators naturally control pests. Incorporating animals into the system further enhances this approach.
Grazing animals not only control weeds and pests by consuming them, but they also enrich the soil with their manure. This, in turn, creates healthy soils, which produce stronger, pest-resistant plants, eliminating the need for chemical interventions and improving crop yield and quality naturally.
