Glyphosate is the most widely used herbicide in the world. It’s used by everyone from farmers protecting and drying their crops to people all over the world who want to keep their gardens and walkways free of weeds.
Glyphosate residues have been found in many different foods (including fish, berries, vegetables, baby formula, and grains), water, and dust. Studies show that even our urine samples, including those of children and pregnant women, are contaminated.
For decades, important health concerns have been raised around glyphosate exposure. The International Agency for Research on Cancer (IARC – 2015) has linked Non-Hodgkin Lymphoma (NHL) to glyphosate and classified it as “probably carcinogenic to humans” (Group 2A). Yet, many agencies across the world have deemed it to be safe for humans, and its widespread use continues.
What is glyphosate?
Glyphosate is a chemical compound designed to kill weeds. It does this by blocking the plant from making certain proteins via the shikimate pathway; this stops the plant from growing. It is found in many herbicide formulations, the most common of which is Roundup®.
The introduction of genetically engineered crops that are resistant to glyphosate (such as soybean, corn, and cotton) has dramatically increased the global use of these herbicides. Farmers also use it as a desiccant to dry out crops before harvest.
A damning report by The Detox Project states that a wide range of foods sold to the American public have unacceptable levels of glyphosate contamination, due in large part to the practice of crop desiccation. Yet we’re told these foods are healthy, especially foods like whole grains, oats, and beans.
The Glyphosate Controversy
GBHs don’t just contain glyphosate, but other ingredients such as surfactants. Manufacturers claim that neither glyphosate nor glyphosate-based herbicides (GBHs) are carcinogenic – and they have industry-sponsored studies to prove it.
In a recent study, Mesnage et al. (2021) showed that Roundup® formulations caused more biological changes linked to carcinogenesis than glyphosate alone.
In a review also published in 2021, Weisenburger states that various types of studies (including epidemiological, animal, and mechanistic) have demonstrated that both glyphosate and GBFs are genotoxic even at low doses and demonstrate “compelling evidence that glyphosate and GBFs are the cause of NHL in humans exposed to these agents”.
Despite this, the scientific community and regulatory bodies have not reached any meaningful consensus on glyphosate or GBHs when it comes to human health.
Non-Hodgkin Lymphoma (NHL)
NHL is a diverse group of blood cancers that develop in the lymphatic system and in particular the lymph nodes, via the lymphocytes (blood cells that are part of the immune system). It develops when lymphocytes mutate and produce abnormal cancerous cells, which may then become tumors.
According to the literature, it’s predominantly B cells that are affected. B cells make antibodies that fight bacteria and infections. When they become cancerous, abnormal cells outgrow the healthy cells.
Because the lymphatic system is found throughout the body, NHL can easily spread, ending up in the spleen, thymus, bone marrow and even the stomach.
NHL is said to be caused by immune system deficiency, dysregulation, or suppression; various infection agents; and certain chemical exposures (including glyphosate).
While there have been decades of independent studies showing the toxic effects of glyphosate and GBHs, there have also been many industry-funded studies. These have in large part shaped the narrative and information on glyphosate and GBHs, especially with regard to health and their environmental impact. (See this 2023 paper on how commercial interests have superseded public health and environmental protection in Canada.)
One independent study worth mentioning was done in 2019 by Zhang et al. They investigated whether there was an association between cumulative exposures to GBH’s and the increased risk of NHL in humans.
They conducted a meta-analysis and reported that the overall meta-relative risk of NHL in GBH-exposed individuals was increased by 41%. The researchers also reviewed available animal and mechanistic studies, which supported their findings. They suggested that the potential mechanisms included immunosuppression, endocrine disruptions, and genetic alterations caused by exposures to glyphosate and GBH’s.
A recent Forbes post (July 2023) indicates that Monsanto has already settled over 100,000 Roundup® lawsuits with another 30,000 still pending. As of May 2022, according to this article, they had already paid out $11 billion in damages.
In June 2022, The Ninth Circuit Court of Appeals rejected the EPA’s (Environmental Protection Agency) argument that glyphosate poses no “unreasonable risk” to the environment and human health and ordered them to reexamine glyphosate’s toxicity to both humans and the environment. The court further stated that the EPA had discounted studies showing a link between glyphosate exposure and an increased risk of NHL.
Nevertheless, this matter is far from being resolved; glyphosate usage continues across the globe.
The use of glyphosate has been under scrutiny for decades. But despite numerous animal and mechanistic studies indicating potential toxicity and carcinogenicity for humans, both industry and regulatory authorities deem it to be safe.
It’s clear that glyphosate has infiltrated our food system, water systems, and soil as well as the bodies of both animals and humans.
What’s left for us as consumers is to make informed choices to protect ourselves. We need to understand the risks of any herbicides and pesticides we use. We can also carefully consider our food choices, focusing more on those least likely to be contaminated.
Sadly, until the science is settled and/or there is a sufficient legal challenge and change in policy, the health and environmental risks will continue.
Grau, D., Grau, N., Gascuel, Q. et al. Quantifiable urine glyphosate levels detected in 99% of the French population, with higher values in men, in younger people, and in farmers. Environ Sci Pollut Res 29, 32882–32893 (2022). https://doi.org/10.1007/s11356-021-18110-0
IARC Monograph on Glyphosate – https://www.iarc.who.int/featured-news/media-centre-iarc-news-glyphosate/
Mesnage R, Ibragim M, Mandrioli D, Falcioni L, Tibaldi E, Belpoggi F, Brandsma I, Bourne E, Savage E, Mein CA, Antoniou MN. Comparative Toxicogenomics of Glyphosate and Roundup Herbicides by Mammalian Stem Cell-Based Genotoxicity Assays and Molecular Profiling in Sprague-Dawley Rats. Toxicol Sci. 2022 Feb 28;186(1):83-101. doi: 10.1093/toxsci/kfab143. PMID: 34850229; PMCID: PMC8883356.
Weisenburger DD. A Review and Update with Perspective of Evidence that the Herbicide Glyphosate (Roundup) is a Cause of Non-Hodgkin Lymphoma. Clin Lymphoma Myeloma Leuk. 2021 Sep;21(9):621-630. doi: 10.1016/j.clml.2021.04.009. Epub 2021 Apr 24. PMID: 34052177.
Bacon, M.-H.; Vandelac, L.; Gagnon, M.-A.; Parent, L. Poisoning Regulation, Research, Health, and the Environment: The Glyphosate-Based Herbicides Case in Canada. Toxics 2023, 11, 121. https://doi.org/10.3390/toxics11020121
Zhang L, Rana I, Shaffer RM, Taioli E, Sheppard L. Exposure to glyphosate-based herbicides and risk for non-Hodgkin lymphoma: A meta-analysis and supporting evidence. Mutat Res Rev Mutat Res. 2019 Jul-Sep;781:186-206. doi: 10.1016/j.mrrev.2019.02.001. Epub 2019 Feb 10. PMID: 31342895; PMCID: PMC6706269.