Mythbusting MAHA: A Reality Check on Glyphosate

A federal reckoning over glyphosate is imminent as the Make America Healthy Again (MAHA) movement gains a foothold with Secretary of Health and Human Services Robert F. Kennedy Jr. wielding influence across President Trump’s cabinet. Banning or restricting glyphosate use in the U.S. will either force producers to incur higher costs by turning to alternatives or worsen the environmental impacts of agriculture.

Debate over the health and environmental impacts of glyphosate, the active ingredient in a range of herbicides including RoundUp, is not new. Concerns about its potential link to health conditions like cancer have led to numerous lawsuits against manufacturers of glyphosate-based products since the 1990s. After decades of paying billions in settlements and with 67,000 pending cases, the CEO of pesticide manufacturer Bayer recently warned that the rising costs of litigation could soon force the company to stop selling Roundup in the U.S. altogether. In what is being described as a last ditch effort, Bayer, along with other manufacturers and farm groups, is lobbying for legislation in several states that would limit the extent to which they could be sued over failure-to-warn claims so long as their product labels comply with federal requirements related to human health risks set by the Environmental Protection Agency (EPA). North Dakota and Georgia were the first states to pass the legislation into law earlier this year.

Beyond the challenges posed by ongoing and expensive litigation, the MAHA movement presents another growing threat to pesticide manufacturers. Kennedy has painted glyphosate as a central villain in his messaging, in which he frequently harkens back to his legal career targeting the manufacturer of RoundUp. MAHA’s growing influence on public discourse has supporters drawing links between chronic disease and various elements of the food and pharmaceutical industries, agricultural practices, and environmental exposures. MAHA-aligned groups like Moms Across America echo Kennedy’s long held criticisms and Trump’s latest pick for U.S. surgeon general calls achieving a pesticide-free world the single most effective strategy to address health issues. This set the stage for MAHA to become strange bedfellows with environmental groups who have long stirred up fear around pesticide contamination in conventional food products and called for pesticide bans. Unfortunately for both camps, and American consumers, the research fails to show that such restrictions will lead to healthier people or a healthier planet.

Comparing glyphosate toxicity with alternatives

Glyphosate is the most commonly used herbicide in the United States. It is applied to an average of 298 million acres or three-quarters of U.S. cropland each year according to data through 2016. A ban or restriction on the use of glyphosate in the U.S. would have the greatest impact on corn, soybeans, and cotton—90 percent of these crops are grown from herbicide resistant varieties. Should the Trump administration ban or restrict glyphosate use in American agriculture, we can expect farmers to swiftly transition to more expensive alternative herbicides. In addition to being higher cost, alternative herbicides can also have greater toxicity and lower efficacy than glyphosate.

Kennedy’s concern with pesticides centers around toxicity. He claims exposure and ingestion are linked to various health issues including non-Hodgkin lymphoma (NHL). Detractors often cite the International Agency for Research on Cancer’s classification of glyphosate as “probably carcinogenic to humans” as evidence glyphosate causes cancer. IARC’s assessment of glyphosate has been called procedurally and scientifically flawed and it overlooked one of the largest longitudinal cohort studies which followed 50,000 pesticide applicators and their spouses. The study found no association between glyphosate and any solid tumors or lymphoid malignancies, including NHL and its subtypes. Per Canada’s 2019 evaluation, “no pesticide regulatory authority in the world currently considers glyphosate to be a cancer risk to humans at the levels at which humans are currently exposed.”

The irony is that the rise of glyphosate use since the 1980s displaced other more toxic pesticides in American agriculture. Glyphosate outperforms alternatives on cost, as well as its effectiveness and relatively low application rate of 20 ounces per acre. However, toxicity needs to be considered along with effectiveness and use intensity per acre to give an accurate picture of an herbicide’s risk profile. Lower toxicity isn’t always lower risk when it comes to real world product use. For example, if a less toxic herbicide is less effective, it might be used more intensively, further exacerbating its effects. While herbicide use intensity has increased since the turn of the century, toxicity has stayed the same or decreased for many crops.

While pesticides can be toxic, human health risks are a function of exposure to a relevant dose. When it comes to acute toxicity, defined as risk associated with exposure during the application process, glyphosate has lower toxicity to humans than 94% of all alternative herbicides. Kennedy often claims, without citing any evidence, that the harms of glyphosate stem from prolonged exposure via low dose ingestion of residues in food products. Risk of prolonged exposure is measured as chronic toxicity, for which glyphosate is lower than 90% of all herbicides. USDA regularly finds that 99% of sampled food products are compliant with federal pesticide residue exposure limits, including for glyphosate. Furthermore, the majority of corn, soybean, and cotton acres in the U.S. grow commodities that are not for direct human consumption. Restricting glyphosate for crops that are used for animal feed, energy, or fiber will have absolutely no impact on health outcomes in consumers.

Today, the leading herbicides used in U.S. corn production include atrazine, mesotrione, glyphosate, acetochlor, and s-metolachlor, according to the most recent data available for 2021. For U.S. soybean production, glyphosate dominates along with 2,4-D and glufosinate. With the exception of mesotrione, all other alternatives outlined in the chart below are more toxic relative to glyphosate based on how many milligrams per kilogram of body weight needs to be injected to cause death in 50% of a test population.

Cornell University developed an Environmental Impact Quotient (EIQ) that summarizes pesticide risk to farmers, consumers, and non-target organisms in one metric. The EIQ calculation weighs chronic and acute dermal toxicity for farmworkers, chronic toxicity to account for constant potential exposure average consumers would have to pesticide residues in food and water, and acute toxicity for fish, birds, bees, and arthropods. The EIQ also considers leaching and surface runoff potential. Active ingredients assessed by Cornell have EIQ values ranging from 13 to 153. The higher the EIQ value, the greater the hazard. While limited in some respects, EIQ values provide a point of comparison. As outlined in the table above, glyphosate ranks in the middle of other leading herbicides when it comes to environmental impact.

Economic realities must be considered in addition to human health and environmental impacts. A recent report, commissioned by Bayer, found that alternative crop protection products can cost producers up to 2.5 times the cost of glyphosate on a per acre basis. An independent 2021 study modelled the economic impact of a hypothetical tax, as a proxy for regulation, on glyphosate in U.S. corn production. The researchers found that even a modest 10% tax on glyphosate, projected to reduce glyphosate use by about 5%, would result in $98 million in annual losses due to increased costs for farmers and decreased corn production. They find that the market economic loss from restricted weed control outweighs any human health and the environmental benefits achieved by switching to alternatives. Notably, the results indicate farmers would not be able to fully compensate for glyphosate restrictions with alternative herbicides. While a reduction in glyphosate use would lead to a modest increase in the use of other herbicides, this substitution is found to be relatively small and not sufficient to offset the reduction in glyphosate, suggesting substitutes aren’t as available or effective.

A lack of sufficient herbicide alternatives could lead farmers to increase mechanical management of weeds through tillage. However, the costs of shifting toward tillage would be nearly double the cost of buying and applying glyphosate. Such a shift would increase production costs for corn, wheat, soy, and wheat by almost $2 billion. To boot, tillage is a practice criticized by regenerative agriculture supporters, including recently announced nominee for U.S. surgeon general Casey Means, for increasing risk of soil erosion and release of carbon stored in soils, as well as for associated fossil fuel emissions.

Meanwhile, glyphosate and glyphosate tolerant crops have contributed to the adoption of reduced tillage practices in U.S. soybean and corn production. The introduction of glyphosate-resistant corn and soybean, coupled with the application of glyphosate, is credited in one study with preventing at least 41 billion pounds of carbon emissions between 1996 and 2013. Stripping U.S. farmers of crop protection tools will jeopardize the fact that over half of U.S. cropland today is managed with reduced or no-till practices.

Let’s all just go organic instead?

Conceivably the Trump administration might not only focus regulatory action on glyphosate, instead targeting a wider swath of synthetic pesticides. Groups like the Center for Biological Diversity recommend the administration revoke EPA tolerances for atrazine, glyphosate, 2-4,D, neonicotinoids, paraquat, and organophosphates and enact policies that would incentivize U.S. agriculture to shift to organic production methods.

A nationwide shift to organic agriculture in the wake of a broad pesticide ban is practically impossible due to a range of systemic constraints. First, organic farming typically produces lower yields, requiring more land to produce a given amount of food. Differences in yield are especially pronounced for certain commodities including wheat. Second, there is not nearly enough manure in the U.S. to fertilize all crops in place of synthetic fertilizers. Therefore, shifting to organic production would also require additional land to produce manure or to grow legumes and other nitrogen-fixing crops that provide needed nutrients. Lastly, organic production is often more costly. Although organic price premiums may enable farmers to make up for the elevated cost of production of farming organically, price premiums can fluctuate. The magnitude of shifting a significant percentage of U.S. farmland to organic can’t be understated. Less than 1 percent of U.S. cropland and pasture is certified organic. Organic sales only made up about 5.5 percent of all retail food sales in 2021.

Even if successful, a shift to using organic alternatives to control weeds, pests, or diseases would not eliminate synthetic pesticide use in agriculture outright. Nor would it necessarily reduce the overall toxicity of agricultural inputs since organic alternatives for weed control are not always less toxic. Whether organic producers use more or less pesticides in terms of volume than conventional production depends on the crop. And the toxicity of organic pesticides can be higher than synthetic alternatives even if the amount applied is orders of magnitude less. For example, organic production of grapes, potatoes, tomatoes, apples, citrus, and stone fruit in the U.S. continues to be reliant on copper sulfate, which is a synthetic chemical allowed under organic standards set by USDA to combat fungal and bacterial diseases. Copper sulfate has a very high LD50 acute toxicity of 450 mg/kg. According to the European Chemical Agency, copper sulfate is “very toxic to aquatic life” and its use has been shown to result in significant consequences to biodiversity. Alternatives to synthetic herbicides that can be used in organic production include clove oil and acetic acid (high concentration vinegar). These non-synthetic herbicides are contact herbicides, meaning they disrupt the cells in the plant tissue they come into contact with, therefore requiring precise and often more frequent application to kill the entire plant. Glyphosate, on the other hand, is a systemic herbicide that disrupts biological processes throughout the plant once absorbed, killing the weed in one go. Glyphosate has a total EIQ value of 41.33. In comparison, acetic acid has a higher hazard value at 45 due to higher potential risks to farmworkers and consumers.

Europe is often venerated by MAHA enthusiasts as having an enviable precautionary regulatory regime for food additives, chemicals, and ingredients. Even President Trump recently asserted that U.S. agriculture is “probably heading towards [the United Kingdom’s] system with no chemicals” under Kennedy’s direction, though the UK does not have a “no chemical” food system. Rather than a beacon, policymakers should view Europe’s farming policy objectives as a cautionary tale. The EU’s Farm to Fork strategy, for example, includes the goal of shifting 25% of production to organic farming. Critics warn such a shift will cause the EU to increase its imports of agricultural products, offshoring environmental damage to other nations, particularly in South America. USDA found that the EU’s plan to increase organic production would increase consumer costs and worsen food security. Other countries have also grappled with these tradeoffs. These exact consequences of a dramatic shift to ban synthetic agricultural inputs were born out in Sri Lanka in 2022. The Mexican government postponed their ban on glyphosate citing concerns that the government has yet to identify an alternative that can replace glyphosate without sacrificing productivity.

Policies that incentivize transitions to organic production, sans synthetic inputs like pesticides and fertilizers, would not only place economic burdens on farmers, but would also have environmental consequences when it comes to spurring increased land used to compensate for yield losses and persistent nitrogen needs. Given the cautious optimism expressed by left leaning environmental organizations that the MAHA wave might be well enough aligned with their goals to be worth jumping on, it’s worth emphasizing the climate consequences of banning synthetic pesticides like glyphosate in favor of organic systems. In large part due to lower on average yields compared to conventional production, a global shift to organic production is projected to lead to a 16-33% increase in land use and a corresponding 8-15% increase in worldwide deforestation.

Without worldwide conversion to vegetarianism, which is next to impossible per current trends, and substantial reductions in global food waste, increasing the share of global agriculture under organic production beyond the 2% it occupies today is expected to increase greenhouse gas emissions from agriculture.

Kennedy’s influence spurs industry action and concern in Congress

Announcements made by President Trump’s USDA and HHS so far have proven more aligned with MAHA moms, far left environmentalists, and consumer protection groups than Republicans in Congress would have hoped. A recent letter from GOP members called on Kennedy and other agency leaders involved in the MAHA Commission to reject misguided health solutions and instead put forward policies supported by sound science and risk-based analyses. The lawmakers emphasize the importance of weighing the role well-regulated agricultural inputs like pesticides play in keeping food prices low and farming profitable.

It’s clear pesticide manufacturers like Bayer and farmers that rely on low toxicity chemical inputs like glyphosate are hinging their strategy on EPA, who has deemed glyphosate as safe for decades and is not under Kennedy’s jurisdiction. This might prove a losing strategy.

Bayer’s multi-state campaign seeks to ensure states defer to the Environmental Protection Agency’s authority over pesticide labeling. That is, if the label on Roundup is approved by the feds, Bayer would be insulated from pesticide injury lawsuits that claim the manufacturer failed to warn users of the product’s health risks. Bayer and other agriculture industry groups also support federal action to shore up the statute that preempts states from adding their own pesticide labeling requirements. If passed, this would provide pesticide manufacturers more consistent regulatory clarity and likely lessen their legal liability. But, with a farm bill still a long way off, it’s clear Congressional action is sure to move more slowly than state legislatures, if at all.

While Kennedy does not oversee the EPA, his role as HHS Secretary grants him considerable influence over public health policy which can interact with environmental regulations. His influence at the cabinet level and interest in shaping policies and programs outside of HHS jurisdiction should not be underestimated. An EPA that abandons reliance on scientific evidence and instead caters to loud calls from activists to ban pesticides in the name of health would disrupt the status quo, rendering any legislative proposals that affect EPA regulations entirely ineffectual.

Look no further than the Food and Drug Administration which has become unrecognizable in a matter of months under Kennedy. The once-cautious agency has said it is considering significant food ingredient policy changes—starting with food dyes like Red 40—without any of the typical processes, like posting a regulatory notice for comment, and top officials blatantly contradicting decades worth of the agency’s prior risk assessments. Food dyes are just the start of a long list of supposed “poisons” in the U.S. food supply Kennedy is keen to address. One can expect current efforts to target food dyes to give way to scrutiny over other ingredients and inputs, like glyphosate, with further reaching implications for the stability and sustainability of our nation’s food supply.

Up next for the MAHA Commission

The MAHA Commission, established by executive order at the start of President Trump’s second term, was tasked with releasing an initial assessment followed by a comprehensive federal policy strategy to end childhood chronic disease. The Commission was directed to focus, in part, on food production techniques and “food ingredients, certain chemicals, and certain other exposures.”

The Commission’s initial assessment outlined several environmental exposures that could impact child health, including crop protection tools with an explicit mention of glyphosate. The report’s discussion of pesticides was considerably more balanced than Kennedy’s past rhetoric regarding their risks, but leaves the door open for more drastic measures in the future. The Commission notes that some studies have raised concerns about possible links between crop protection tools and adverse health outcomes in children but recognizes that instigating a sudden change to production practices and inputs could jeopardize agricultural production and the global food supply. The Commission also contends that, when it comes to pesticides, EPA has a robust risk- based approach to consider risks to human health and the environment. Despite these assertions, the Commission doesn’t rule out the possibility of further regulating or restricting crop protection tools.

The report makes a promise to not go beyond risk- and scientific processes without “thoughtful consideration,” indicating the administration could take actions that aren’t based in science or that go beyond congressional authority. The Commission perpetuates the idea that if there were natural alternatives to synthetic products that had similar efficacy and cost, those alternatives would be preferred. The entirety of the report appeals to the nature fallacy by questioning the safety of synthetic chemicals in the U.S. food and agriculture system. The report fails to acknowledge the environmental and human health benefits of synthetic crop protection tools. Holding costs and efficacy constant, some synthetic pesticides will prove superior across other important factors like toxicity, application rates, and environmental persistence. Pesticides are also an important part of fruit and vegetable production, keeping fresh produce an affordable part of children’s diets. Comparisons across this range of factors are worth making, but should adhere to, rather than abandoning, sound science.

The MAHA Commission will now turn to drafting a policy agenda to address the disease drivers identified in its initial assessment. As the Commission considers proposals relevant to research initiatives, the forthcoming update to the Dietary Guidelines, or regulatory actions, the Commission should prioritize supporting farmers in reducing the impacts of pesticide use without sacrificing yields.

USDA should support the research, development, and adoption of technologies and products that enable both organic and conventional producers to reduce the toxicity of pesticide use, either by using less or employing products with better efficacy and lower toxicity. USDA conservation programs should be leveraged to scale the use of precision agriculture technologies to improve application of synthetic pesticides. Federal research dollars should be dedicated to developing less toxic alternatives to use in organic production systems, such as alternatives to copper sulfate to better fight fungal and bacterial diseases. In addition, the Commission should propose that federal agencies support public and private plant breeding programs to develop crop varieties that have improved pest and disease resistance, reducing the need for pesticides.

When it comes to evaluating the effects of agricultural pesticides on human health and determining pesticide residue limits, it is imperative that the Commission rely only on science backed human health risks and differentiate risks based on acute vs. chronic toxicity levels. The Commission should emphasize the importance of EPA putting adequate staffing and resources behind farmworker pesticide surveys and USDA continuing work under its Pesticide Data Program (PDP). Activities led by PDP include sampling, testing, and reporting of pesticide residues on agricultural commodities in the U.S. food supply.

All of the Commission’s proposals should appropriately weigh the extent to which pesticide bans or restrictions would incentivize substitutions with more toxic products or lead to declines in agricultural productivity and increases in food prices. Implementing policies that fail to anticipate these follow on effects would not only have food security implications at home, but also jeopardize America’s global leadership as a food exporter. Further, the Commission should refrain from asserting misleading links between the use of glyphosate in non-food crops, dietary exposure, and human health outcomes.

Ultimately, the Commission must resist the urge to center agricultural practices and inputs as a silver bullet for addressing disease. Employing a narrow focus on specific on-farm agricultural inputs, like glyphosate, and attributing chronic health conditions to agricultural production techniques is not only misguided but detracts from public health interventions that could actually curb rates of chronic illness.

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Thank you to Jon Entine, Executive Director of the Genetic Literacy Project, for contributing feedback on this article.