Concern follows disputed study calling glyphosate a probable carcinogen
When Monsanto created the herbicide Roundup, it was supposed to be much safer than older ones.
That presumption rested on the fact that Roundup’s active ingredient — glyphosate — disrupts a metabolic pathway found in plants, but not in animals.
Later, Monsanto realized that if it could genetically engineer crops to resist the effects of Roundup, it could sell seeds for “Roundup ready” varieties of corn, soy, and more.
Since Monsanto developed glyphosate in the early 1970s, it’s become the most widely used herbicide in the United States, and sales of Roundup now account for about half of Monsanto’s annual revenues.
But as the sarcastic saying — which could be directed at Monsanto — goes, “how’s that workin’ out for ya?”.
It sure isn’t working out for Bayer — the giant German corporation that bought Monsanto in June of 2018 — whose share price has plummeted in response to a flood of lawsuits accusing Roundup and/or glyphosate of causing cancer.
Roundup is reaping huge damage awards
Today, Bayer faces more than 13,400 Roundup-related lawsuits — a situation that could threaten the firm's viability.
Juries have been sympathetic to plaintiffs’ claims that Roundup caused or promoted cancer — usually some form of leukemia or lymphoma, most often a cancer called non-Hodgkin’s lymphoma (NHL).
Most recently, a California jury awarded Alva and Alberta Pilliod — who both suffer from NHL — $55 million in compensatory damages and $2 billion in punitive damages.
Last March, a California jury awarded Edwin Hardeman $80 million in damages in response to his claim that Roundup caused his NHL cancer, and in August 2018, a California jury awarded school groundskeeper Dewayne Johnson $289 million in damages for the same reason.
Both awards were later reduced, as will the $2 billion award in the Pilliod case, because punitive damages in a lawsuit can’t total more than nine times the compensatory damages. Nonetheless, punitive damages in the Pilliod case could total $495 million — just under one-half billion dollars.
Importantly, the only report that’s found glyphosate to be a probable carcinogen is the subject of significant scientific criticism. See “Does glyphosate cause cancer? Recent report stands alone”, below.
Regardless, Roundup contains potentially problematic surfactants (detergent-like compounds) that help glyphosate adhere to and enter plants. Some of these surfactants are suspected endocrine disruptors, and one — polyethoxylated tallow amine (POEA) — can damage human cells.
Studies suggest that the combination of glyphosate and surfactants in Roundup is more toxic than glyphosate alone. And in 2016, European regulators' concerns about POEA led them to ban its use in glyphosate-based herbicide products.
And if Bayer and its shareholders didn’t have enough worries, new findings suggest that Roundup may also cause or promote liver disease.
Glyphosate linked to non-alcoholic fatty liver disease
The new study comes from researchers at the University of California at San Diego (USCD) School of Medicine, who knew that glyphosate had previously been linked to liver disease in animals.
“There have been a handful of studies, all of which we cited in our paper, where animals either were or weren’t fed Roundup or glyphosate directly, and they all point to the same thing: the development of liver pathology,” said team leader Paul J. Mills, PhD. “So I naturally thought, ‘Well, could it be exposure to this same herbicide that’s driving liver disease in the U.S.?’”
And the results of their new study — the first of its kind — show an association between presence of the herbicide in urine and an increasingly common category of liver disease.
The UCSD team decided to look for glyphosate in urine collected from two patient groups — those with a diagnosis of nonalcoholic steatohepatitis (NASH) — an advanced stage of nonalcoholic fatty liver disease (NAFLD) — and those without the liver disorder.
They examined urine samples from 93 patients: 41% were male, 42% were white or Caucasian, and 35% were Hispanic or Latino (Mills PJ et al. 2019).
The participants were originally recruited as part of a larger study at the UC San Diego NAFLD Research Center that was conducted between 2012 and 2018. That study employed liver biopsies to determine the presence or absence of NAFLD.
(Seafood source omega-3 fatty acids may help prevent NASH: see Rising Liver Risk Deterred by Omega-3s.)
The UCSD team’s findings raise real concerns about glyphosate and liver health. They found significantly higher levels of glyphosate in urine from patients with NASH than in urine from people with a healthy liver — regardless of a participants’ age, race, body mass index (BMI), ethnicity or diabetes status.
According to Dr. Mills, these findings, when combined with those of prior animal studies, suggest a link between the commercial use of glyphosate on food crops — which has risen sharply over the past 25 years — and the prevalence of NAFLD in the United States, which has also been on the rise for two decades.
To explore this concern further, Mills plans to place a group of volunteer patients on an all-organic diet and track them over the course of several months, to see whether and how an herbicide-free diet might affect biomarkers of liver disease.
“The increasing levels [of glyphosate] in people’s urine very much correlates to the consumption of Roundup treated crops into our diet,” said Mills.
But while this study shows a link between glyphosate and liver disease in humans, it’s just the tip of an iceberg involving countless diseases and chemicals. As Dr. Mills said, “There are so many synthetic chemicals we are regularly exposed to. We measured [the effects of] just one [on one organ].”
Does glyphosate cause cancer? Recent report stands alone
In March of 2015, the International Agency for Cancer Research (IARC) — part of the UN’s World Health Organization — declared glyphosate a “probable carcinogen.”
No other governmental body — including the U.S. EPA, Germany’s Federal Institute for Risk Assessment, and the European Food Safety Agency (EFSA) — agrees with the IARC’s conclusion.
Members of the IARC published a seemingly persuasive rebuttal of the other agencies' positions regarding the carcinogenicity of glyphosate and/or Roundup. (Portier CJ et al. 2016).
Still, many scientists criticize the IARC report, perhaps with reason.
For example, the IARC said that glyphosate can cause genotoxicity (DNA damage) and therefore cause mutations that promote cancer. But a well-known pesticide authority, emeritus professor Keith Solomon of the University of Guelph, characterized that IARC conclusion as “totally wrong.”
Professor Solomon led the only study cited by the IARC to support its conclusion that glyphosate is genotoxic, hence potentially cancer-promoting. As Solomon said, “There’s no evidence [from our study in Colombian government workers who were spraying glyphosate copiously to destroy illicit coca farms] that glyphosate is genotoxic.”
And the Reuters news agency reported that it found 10 instances in which “a negative conclusion about glyphosate leading to tumors was either deleted or replaced with a neutral or positive one” and revealed that the IARC’s interim draft report found little evidence that glyphosate is carcinogenic.
Further, the IARC placed glyphosate in the same “probable” (unconfirmed) carcinogen category as emissions from frying food, hairdressing products, and burning wood — which designates probable carcinogenicity in relation to gross exposure to a substance — rather than ingestion of trace amounts in air, water, or food.
As Kate Guyton, one of the scientists who worked on the IARC’s glyphosate report, said: “I don’t think home use is the issue. It’s agricultural use that will have the biggest impact. For the moment, it’s just something for people to be conscious of.”
Clearly, cancer and other health risks from glyphosate, such as liver damage, should be researched aggressively. We certainly can’t trust Monsanto or Bayer.
Other herbicides may be much more dangerous
The attention generated by the IARC report has shifted the spotlight away from dozens of other agrichemicals that are more acutely toxic and/or more likely carcinogenic.
The U.S. EPA and/or OSHA classify virtually all major herbicides — including the rotenone and copper sulfate used on some organic farms — as more acutely toxic (either slightly or extremely) than glyphosate, and some as probable carcinogens.
- Andreotti G et al. Glyphosate Use and Cancer Incidence in the Agricultural Health Study. J Natl Cancer Inst. 2018 May 1;110(5):509-516. doi: 10.1093/jnci/djx233.
- Mesnage R, Antoniou MN. Facts and Fallacies in the Debate on Glyphosate Toxicity. Front Public Health. 2017 Nov 24;5:316. doi: 10.3389/fpubh.2017.00316. eCollection 2017.
- Mills PJ et al. Excretion of the Herbicide Glyphosate in Older Adults Between 1993 and 2016. JAMA. 2017 Oct 24; 318(16): 1610–1611. Published online 2017 Oct 24. doi: 10.1001/jama.2017.11726
- Mills PJ et al. Glyphosate Excretion is Associated With Steatohepatitis and Advanced Liver Fibrosis in Patients With Fatty Liver Disease. Clin Gastroenterol Hepatol. Available online 4 April 2019. DOI: https://doi.org/10.1016/j.cgh.2019.03.045
- Mink PJ, Mandel JS, Sceurman BK, Lundin JI. Epidemiologic studies of glyphosate and cancer: a review. Regul Toxicol Pharmacol. 2012 Aug;63(3):440-52. doi: 10.1016/j.yrtph.2012.05.012. Epub 2012 Jun 7. Review.
- Portier CJ et al. Differences in the carcinogenic evaluation of glyphosate between the International Agency for Research on Cancer (IARC) and the European Food Safety Authority (EFSA). J Epidemiol Community Health. 2016 Aug;70(8):741-5. doi: 10.1136/jech-2015-207005. Epub 2016 Mar
- Tarazona JV, Court-Marques D, Tiramani M, Reich H, Pfeil R, Istace F, Crivellente F. Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC. Arch Toxicol. 2017 Aug;91(8):2723-2743. doi: 10.1007/s00204-017-1962-5. Epub 2017 Apr 3. Review
- Ward EM. Glyphosate Use and Cancer Incidence in the Agricultural Health Study: An Epidemiologic Perspective. J Natl Cancer Inst. 2018 May 1;110(5):446-447. doi: 10.1093/jnci/djx247.