Widely Used ‘Chemical Cocktails’ Tied to Gut Damage, Inflammation
Herbicide mixtures widely used on industrial farms may damage the gut, disrupt healthy bacteria and trigger inflammation at exposure levels regulators currently consider safe, according to a new peer-reviewed study.
The research, published in April in Archives of Toxicology, examined glyphosate — the active ingredient in Roundup weedkiller — alongside two other common herbicides, dicamba and 2,4-D. Rats exposed to the chemical combinations developed intestinal inflammation, tissue damage, oxidative stress and signs of “leaky gut.”
The findings raise concerns about how the safety of agrochemicals is typically evaluated — because regulators generally assess chemicals one at a time rather than in the combinations people and wildlife are actually exposed to in the environment.
“This study comprises the most comprehensive investigation of the impact of glyphosate on gut structure and function,” the authors wrote. The study is also the first to examine the combined effects of glyphosate with dicamba and 2,4-D at “regulatory relevant” doses deemed to be safe, the authors said.
“The findings show that the levels of these herbicides, when ingested as a mixture, have adverse effects and are not safe at all – and that regulatory assurances of safety are false,” according to GMWatch, which reported on the study.
The study, led by glyphosate expert Michael Antoniou, Ph.D., comes amid escalating concerns about chronic exposure to agricultural chemicals, particularly in communities near large-scale farming operations.
Glyphosate, the key active ingredient in Roundup, has long been controversial because it may cause cancer.
But scientists are increasingly focusing on more subtle biological disruptions — especially impacts on the gut microbiome, inflammation and metabolic health.
Antoniou told GMWatch that the results of the study show that such effects must be included in regulatory safety studies.
It also shows that “chemical pollutants need to be evaluated for toxicity as mixtures and not only as individual agents, as is currently practised by regulators in all nations.”
Herbicide mixtures triggered gut inflammation, tissue damage at ‘safe’ levels
In the new study, the researchers exposed rats to glyphosate alone and to glyphosate combined with dicamba and 2,4-D — two herbicides commonly paired with glyphosate for use on genetically engineered crops designed to withstand multiple weedkillers.
The doses they used mirrored levels regulators in Europe “deemed to be safe” for daily exposure. They studied exposure beginning prenatally.
Animals exposed to the herbicide mixtures showed chronic inflammation in the intestine, vascular congestion, tissue abnormalities and structural changes in the small and large intestines — important regions of the digestive tract.
The animals also exhibited signs of increased intestinal permeability, which is often called “leaky gut,” a condition linked to inflammatory and autoimmune disorders.
Effects were more extreme in the large intestine, and female rats were particularly vulnerable.
Glyphosate alone produced concerning effects, but the herbicide mixtures caused even greater damage.
The researchers also found alterations in the microbial communities in the gut, confirming that herbicides may interfere with the complex ecosystem of bacteria essential to digestion, immune regulation and metabolic functioning.
Regulatory agencies typically evaluate pesticides individually, despite the fact that real-world exposures generally involve chemical combinations, the authors said. Critics have long argued that this approach ignores the possibility of synergistic effects — where mixtures produce harms that aren’t seen with individual compounds.
The authors underscored the fact that the doses they tested were not excessively high.
They compared a control group to a group given glyphosate at the European Union’s (EU) “acceptable daily intake” level and one at the “no-observed-adverse-effect level” — a toxicology term that indicates the level at which a toxin is thought to be safe.
They compared those groups to a group exposed to glyphosate, 2,4-D and dicamba at their EU “acceptable daily intake” levels.
The authors called for additional research to understand the mechanisms involved and the implications for long-term health.
‘Particularly worrying for citizens of the USA’
Antoniou said the group’s findings are “particularly worrying for citizens of the USA, where there has been a massive escalation in the use of 2,4-D and dicamba along with glyphosate in recent years due to vast field infestation of glyphosate-resistant weeds and the subsequent launch of glyphosate/2,4-D/dicamba-tolerant GMO crops.”
He said human biomonitoring studies in the U.S. show a dramatic increase in urinary levels of 2,4-D and dicamba since the introduction of those crops.
“Thus our findings have serious public health implications,” Antoniou said.
Monsanto brought glyphosate to the market in 1974, but its use skyrocketed in the 1990s, when the company’s “Roundup Ready” crops, genetically engineered to withstand the herbicide, flooded global agricultural markets.
The chemical is linked to health problems that range from cancer to liver damage to neuroinflammation to disruption of gut microbes.
Bayer, which acquired Monsanto in 2018, has already paid more than $12 billion to resolve lawsuits filed against Monsanto before the acquisition. The company still faces more than 60,000 lawsuits nationally, largely over injuries from the use of Roundup in farming, landscaping and gardening.
People increasingly exposed to ‘chemical cocktails’
After years of widespread Roundup use, glyphosate-resistant weeds developed. In response, agro-chemical companies developed crops that could also tolerate other herbicides.
Monsanto was also the first to commercialize dicamba-resistant seeds in 2016, and according to the U.S. Department of Agriculture, use of herbicide-resistant seeds that can withstand the application of glyphosate, dicamba and 2,4-D is common today.
In February of this year, the U.S. Environmental Protection Agency (EPA) announced that it reapproved products containing the herbicide dicamba for use on genetically engineered cotton and soybeans.
It reapproved the toxin despite federal court decisions in 2020 and again in 2024 striking down the agency’s previous approvals of the weedkiller as unlawful.
Since its first approval in 2016, dicamba drift — the unintentional movement of the chemical to areas near where it was sprayed — has damaged millions of acres of farmland and caused devastating damage to orchards, vegetable farms, home gardens, native plants, trees and wildlife refuges across the country.
As agro-chemical companies change their chemical formulations to include more toxins, people are increasingly exposed to “chemical cocktails” that haven’t been studied for their effects on human health, GMWatch wrote.
source childrenshealthdefense.org
Tom
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The “regulators” have no clue as to what is safe. Exposure will be variable as will the condition of the person exposed. The usual stupidity is to figure on a one-size-fits-all standard which means absolutely nothing. How many real trials or tests have been done? Poisons are poisons no matter the amount and there are no safe amounts.
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