What if the problem isn’t just what we eat, but what’s in what we eat?
Obesity. Insulin resistance. Non-alcoholic fatty liver disease. Metabolic syndrome. These conditions have become alarmingly common in modern society — not just in adults, but increasingly in children and even infants. For decades, we’ve been told to look inward for answers: eat less, move more, try harder. But what if the real driver of metabolic dysfunction isn’t just calories and lifestyle, but chemicals in our food supply that were never meant to be there?
One of those chemicals is glyphosate — the most widely used herbicide in the world and the active ingredient in products like Roundup®. And emerging research is beginning to link even low-level glyphosate exposure with metabolic disruption, from gut microbiome shifts and hormone imbalances to insulin resistance and liver damage.
In this article, we examine the scientific evidence connecting glyphosate to metabolic disorders, including newly released studies that suggest even dietary-level exposure during pregnancy may have generational consequences. If you’ve ever wondered why it feels like modern health problems are getting harder to explain — this might be one of the missing pieces.
A Paradigm Shift: From Acute Toxicity to Subtle Disruption
When regulators evaluate chemicals like glyphosate, they typically look for signs of acute toxicity: Does it cause cancer? Death? Major organ failure? If not, it often gets the all-clear. But many chemicals don’t work that way. Instead of delivering an obvious “toxic” dose, they interfere with the body’s regulatory systems — including hormones, mitochondria, and the gut microbiome — in ways that may take months or years to manifest.
This is the growing field of endocrine disruption and metabolic toxicology, and glyphosate is increasingly on the radar.
A 2021 Frontiers in Endocrinology mini-review (Romano et al.) explores how glyphosate and its formulations may disrupt thyroid hormone pathways and endocrine balance — a plausible gateway to metabolic dysregulation.
A 2024 review in Frontiers in Toxicology likewise evaluates glyphosate’s possible roles as an endocrine disruptor across multiple organ systems.
Meanwhile, a 2024 systematic review in Food & Function directly linked glyphosate exposure to disruptions in the gut microbiome, intestinal structure, and metabolic function — reinforcing the idea that chronic, low-dose exposure could contribute to obesity, insulin resistance, and other non-communicable diseases.
These findings suggest a need to radically rethink how we assess glyphosate’s “safety” — especially in vulnerable populations like pregnant women, children, and those already at risk of metabolic disease.
The CHAMACOS Study: Glyphosate and Childhood Metabolic Syndrome
One of the most compelling human studies to date is the 2023 CHAMACOS cohort paper from UC Berkeley researchers, which followed pregnant women and their children in agricultural California communities.
Their findings? Higher urinary glyphosate levels in pregnant women were associated with a 61% increased risk of metabolic syndrome in their children by age 18 — a cluster of symptoms that includes abdominal obesity, high blood pressure, insulin resistance, and abnormal cholesterol levels.
Even more striking, this risk persisted independent of diet, socioeconomic status, or birth weight, suggesting a direct link between glyphosate exposure in the womb and long-term metabolic health outcomes.
These findings mirror what has long been seen in animal models, where glyphosate exposure during gestation leads to insulin resistance, liver changes, altered fat metabolism, and disrupted glucose regulation.
The 2025 UBC Mouse Study: A Wake-Up Call
In July 2025, a groundbreaking mouse study from the University of British Columbia made headlines for exposing just how far-reaching glyphosate’s effects may be — not just on individuals, but across generations.
Pregnant mice were exposed to either 0.01 mg/kg/day (a dietary-level dose) or 1.75 mg/kg/day (the EPA’s official ADI) throughout pregnancy. Researchers then tracked their offspring (F1) and the next generation (F2) for a range of health outcomes.
The results?
- Elevated fasting glucose and insulin resistance in offspring, even at the lower dose
- Microbiome alterations associated with impaired metabolism
- Liver enzyme disruptions and signs of early-stage fatty liver disease
- Behavioural changes linked to the gut–brain axis
- Systemic inflammation, mitochondrial stress, and immune imbalances
Even at the lowest dose, the study observed multigenerational impacts — indicating that glyphosate exposure during pregnancy could potentially “program” metabolic dysfunction in future generations.
These findings should be especially concerning for regulators like MPI, who continue to focus solely on short-term, high-dose studies while ignoring emerging science on chronic, low-level exposures.
For a deeper dive into the UBC team’s methodology and what their findings mean for New Zealand, see our full article: Prenatal Glyphosate Exposure and Generational Risk.
Gut Microbiome Disruption: A Key Mechanism
A growing number of studies have shown that glyphosate disrupts the gut microbiome — A growing body of research now shows that glyphosate can disrupt the gut microbiome — the trillions-strong community of microbes that regulate digestion, inflammation, immune function, and yes, metabolic health.
Glyphosate acts by inhibiting the shikimate pathway — a pathway found in plants and many gut bacteria (though not in human cells). Disruption of this pathway in gut bacteria can have downstream effects on nutrient absorption, glucose regulation, satiety signaling, and fat storage.
For example:
Lehman et al. (2023) found that low-dose glyphosate exposure alters gut microbiota composition and modulates gut homeostasis in mice, reducing beneficial commensals and shifting the balance toward less favorable taxa.
A 2024 systematic review, “Effects of glyphosate exposure on intestinal microbiota, metabolism and microstructure” (da Cunha Ignácio et al.), concluded that glyphosate formulations can induce intestinal dysbiosis, impair gut permeability, damage microvilli structure, and disrupt metabolic processes in animal models.
Walsh & Hill (2023), in their review “Impact of glyphosate (Roundup™) on the composition and functionality of the gut microbiome,” explain how glyphosate exposure may suppress beneficial genera like Lactobacillus and Bifidobacterium, while shifting the microbiome toward more inflammation-promoting species.
This microbial imbalance — or dysbiosis — has been linked in many studies to obesity, insulin resistance, type 2 diabetes, and even mood disorders.
Mitochondrial Damage: Blocking the Body’s Energy Systems
In addition to disrupting gut health, glyphosate and glyphosate-based herbicides have been shown in animal and cellular studies to interfere with mitochondrial function — the process by which cells generate energy. For example:
Glyphosate-based herbicide disrupts energy metabolism and activates inflammatory response through oxidative stress in mice liver, (Qi et al., 2023) —
Found that GBH exposure altered mitochondrial respiration, membrane potential, and enzyme activity, while elevating oxidative stress markers in liver tissue.
Effects of glyphosate exposure on Western diet-induced non-alcoholic fatty liver disease in mice (Romualdo et al., 2023) — Showed that glyphosate worsened Western diet–driven fatty liver disease by amplifying oxidative stress, inflammation, and transcriptomic disruption, consistent with mitochondrial dysfunction.
Comparative effects of the Roundup and glyphosate on mitochondrial oxidative phosphorylation, (Peixoto, 2005) — Demonstrated that glyphosate-based herbicides can impair the electron transport chain and reduce ATP production, pointing to mitochondrial toxicity.
Long-Term Effects of Perinatal Exposure to a Glyphosate-Based Herbicide on Melatonin Levels and Oxidative Brain Damage in Adult Male Rats (Cattani et al., 2023) — Reported that perinatal GBH exposure caused oxidative brain damage and neuronal stress in adult rats, reinforcing concerns about mitochondrial vulnerability.
Together, these findings suggest that glyphosate may act as a mitochondrial toxin, reducing ATP production and increasing cellular stress — two known drivers of metabolic dysfunction. When combined with a Western diet, which already burdens mitochondria and metabolic pathways, glyphosate may act as an accelerant — pushing the body closer to disease.
Fatty Liver Disease and Glucose Regulation
Another consistent finding across animal and in vitro studies is glyphosate’s potential role in the development of non-alcoholic fatty liver disease (NAFLD) — a condition now affecting nearly one in four adults globally.
A 2017 open-access study titled Multiomics reveal non-alcoholic fatty liver disease in rats following chronic exposure to an ultra-low dose of Roundup herbicide (Mesnage et al.) exposed animals to ultra-low, environmentally relevant levels of a commercial Roundup® formulation (≈4 ng/kg bw/day) for two years. Using both proteomics and metabolomics, the researchers found evidence of steatosis, oxidative stress, necrosis, and molecular biomarkers consistent with NAFLD. They concluded that even extremely low-dose exposure can result in liver dysfunction aligned with this increasingly common disease.
In other studies, glyphosate-exposed mice showed impaired glucose tolerance, elevated liver enzymes, and altered gene expression related to insulin signaling.
These effects were often seen at doses far below regulatory limits — suggesting that the “safe” daily intake levels set by agencies like the EPA or MPI may not be protective when it comes to metabolic health.
Why This Matters for New Zealand
New Zealand regulators continue to claim that glyphosate is safe when used as directed. But the science tells a more complicated story — especially when it comes to metabolic disorders.
We’re not just talking about rare cancers or high-dose poisonings. We’re talking about low-level, chronic exposure to residues in common foods like bread, cereal, oats, and honey — foods that many Kiwi families eat every day.
We’ve already found glyphosate in Weet-Bix, supermarket bread, and multiple brands of New Zealand honey. Now imagine the cumulative effect of those daily doses over a lifetime. Or worse — during pregnancy, when the next generation is being formed.
Can we really say glyphosate is safe in our food supply when multiple studies suggest it may be quietly fuelling the very health crises we’re struggling to solve?
Looking Ahead: Time to Rethink Our Priorities
We don’t need to wait for perfect certainty before taking action. The science has already reached a point where precaution is not just reasonable — it’s responsible.
Public health experts have long warned that metabolic diseases are the new pandemic. If we continue to ignore environmental contributors like glyphosate, we’re fighting that battle with one hand tied behind our back.
It’s time for New Zealand to fund independent biomonitoring, enforce lower detection thresholds in food testing, and take a hard look at whether glyphosate has any place near our food chain — let alone in it.
Where This Leaves Us
The next time someone says glyphosate is “safe,” ask them: safe by what definition?
Because when it comes to metabolic health, the cost of inaction isn’t theoretical — it’s showing up in our waistlines, our blood tests, our fertility stats, and our kids.
What You Can Do
✅ Share this article to raise awareness about prenatal glyphosate risks
✅ Support our independent food testing campaign to find out what’s really in our bread, cereal, and honey
✅ Ask your school, council, or sports club to stop using glyphosate near children
✅ Demand that your MP oppose the proposed MRL increases
✅ Join our mailing list for updates, test results, and action alerts
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Resources & References
Before we’re told to “trust the science,” we should ask: which science?
The studies below don’t rely on industry-funded reassurances or vague regulatory thresholds. They represent a growing body of independent, peer-reviewed research pointing to glyphosate’s potential role in metabolic dysfunction, obesity, and related chronic diseases — even at levels well below what regulators consider “safe.” This isn’t fringe theory. It’s emerging science we ignore at our peril.
Prenatal exposure to dietary levels of glyphosate disrupts metabolic, immune, and behavioral markers across generations in mice
This is the core study we’ve been discussing. It exposed mice during gestation to glyphosate at realistic dietary levels and the EPA’s ADI, then tracked outcomes in two generations — finding disturbances in immunity, metabolism, gut barrier, behaviour, and microbiome links.
Association of Lifetime Exposure to Glyphosate and Aminomethylphosphonic Acid (AMPA) with Liver Inflammation and Metabolic Syndrome at Young Adulthood – CHAMACOS Study
A human cohort study linking higher glyphosate / AMPA exposure (prenatal + lifelong) to increased risk of metabolic syndrome and liver inflammation by age 18 — supporting a translational bridge to the animal data.
Multiomics reveal non-alcoholic fatty liver disease in rats following chronic exposure to an ultra-low dose of Roundup herbicide
In this rat study, extremely low chronic Roundup exposure (over two years) produced molecular signs of NAFLD (fat accumulation, inflammation, fibrosis) via multiomics (proteomic & metabolomic) analysis.
Long-Term Effects of Perinatal Exposure to a Glyphosate‑Based Herbicide on Melatonin Levels and Oxidative Brain Damage in Adult Male Rats
This study exposed pregnant/lactating rats to a glyphosate-based herbicide, then measured in adult offspring reduced melatonin, oxidative stress in brain tissue, and compensatory antioxidant enzyme changes — relevant for oxidative/metabolic stress pathways.
Impact of Glyphosate on the Development of Insulin and Its Signaling Pathways in the Liver
This rodent experiment found that glyphosate exposure raised fasting glucose and insulin, reduced liver insulin receptor and GLUT2 expression, and induced proinflammatory signaling — illustrating direct disruption of hepatic insulin signaling.
Impact of glyphosate (Roundup™) on the composition and functionality of the gut microbiome.
This review discusses how glyphosate formulations may suppress beneficial genera (e.g., Lactobacillus, Bifidobacterium) and tilt gut communities toward inflammation‑promoting taxa, supporting microbiome‑mediated pathways of metabolic harm.
Effects of Glyphosate Exposure on Intestinal Microbiota, Metabolism and Microstructure
A recent systematic review investigating how glyphosate (and formulations) impact gut microbiota, intestinal barrier integrity, metabolic markers, and gut structure in animal models — a foundational resource linking microbial and metabolic disruption.
Low-dose glyphosate exposure alters gut microbiota composition and modulates gut homeostasis
A more direct animal experiment showing that low-dose glyphosate shifts gut bacterial populations, reduces beneficial taxa, and alters composite microbiome structure — providing empirical evidence of dysbiosis at low exposure.
Overview of Human Health Effects Related to Glyphosate
This broad review surveys glyphosate’s potential impacts on endocrine systems, reproduction, metabolic endpoints, oxidative stress, and organ systems — useful as a comprehensive reference to the health risk landscape.
Could Glyphosate and Glyphosate-Based Herbicides Be Associated With Increased Thyroid Diseases Worldwide?
This mini‑review examines evidence of glyphosate’s interference with thyroid hormone pathways and endocrine regulation — providing an anchor for the biological plausibility of metabolic disruption.
Glyphosate’s Hidden Legacy: Prenatal Exposure Linked to Multigenerational Harm
This companion article explores how glyphosate gets into our food — from pre-harvest spraying to processing — and why prenatal exposure deserves urgent attention. It unpacks the evidence showing glyphosate can cross the placental barrier, with implications for fetal development, immune priming, and long-term health.
The weight of evidence is shifting — but policy is lagging behind.
As this research makes clear, glyphosate’s effects go far beyond weed control. They ripple through ecosystems, food systems, and human biology in ways we’re only beginning to understand. If the science has moved on from “how much kills a rat,” maybe it’s time our regulations, risk assessments, and public health priorities did too.
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