On Dec 11, 2023, a clinical report titled, “Use of Genetically Modified Organism (GMO) – Containing Food Products in Children” was released from the American Academy of Pediatrics (AAP). This was accompanied by an educational article meant for parents titled, “Are GMO Foods Safe for My Child? AAP Policy Explained” on the AAP’s healthychildren.org website.
As a pediatrician with an interest in this subject, I was excited to read these papers. I thought it would be great to see the AAP lay to rest concerns about food containing ingredients derived from genetic engineering (GE). Instead, what I found was a piece filled with misinformation and missing key articles that support the well-researched conclusion that there is no legitimate evidence of negative health effects after more than three decades of intense study and surveillance.
After I picked my jaw up off the ground and took some deep breaths to calm my fury, I dove into the concerns presented, trying to be open minded that maybe I had something to learn. After thorough review, though, I’m not convinced by the concerns presented in this report. In fact, I’m majorly concerned that this piece is going to spread like wildfire and spark unnecessary fear amongst healthcare workers and then onto patients. I can’t let this be. So, I’m going to use this article to help dispel inaccurate information and unfounded worries brought up by this report. Here goes!
Glyphosate/pesticide residue concerns
I initially assumed the concerns about “GMOs” would be regarding risks associated with genetic modification. Rather, the authors make clear statements that they are chiefly concerned with increased and persistent use of herbicides on GE crops and that this pesticide exposure is harmful to health. Regarding herbicide exposure they write, “These toxic and carcinogenic risks substantially overshadow any theoretical risks to children’s health that may be associated with the introduction of novel genes into corn, soybeans, and other food crops.” In other words, their primary issue with genetic engineering is not the product itself, rather the dietary exposure to herbicide residues. They go on to detail their pesticide concern, targeting the herbicide glyphosate.
Let’s take apart their concerns:
Farmers use glyphosate because it is a nonselective herbicide that kills all plants, except for those that are genetically engineered to tolerate it. Farmers plant seeds, allow weeds and crop to grow together, then apply a light concentration of the herbicide (more on this later) which kills the weeds and leaves the crop to dominate the field. While highly toxic to plants, its acute and chronic toxicity to non-target organisms is exceedingly low (more info can be found here, and here).
As the AAP report points out, glyphosate use has indeed gone up in the decades since it was first introduced in the mid 1970’s. But the authors of this piece would have you believe that this increase is due to unchecked agricultural abuses. Rather, farmers choose to use glyphosate to control weeds instead of using other herbicides (like atrazine) or repetitive tilling, which disturbs soil and promotes erosion. Glyphosate is chosen as an effective and safe option that helps protect our food supply with limited unwanted effects. The other omitted fact is at the same time as glyphosate use has increased, use of other harsher chemicals have been majorly decreasing (great visual of these volume shifts here). Even more, the volume of overall pesticide use (and use of more toxic pesticides) over time has actually decreased.
This report also briefly mentions fears about the toxicity of two other herbicides – 2,4 D as well as Dicamba. I won’t spend too much time on these but thought I could briefly address their worries. Both 2,4 D and Dicamba are commonly used on lawns, gardens, and golf courses. They are also used in agriculture on crops like corn and soybeans. When assessing 2,4 D toxicity, you’d have to be massively exposed repeatedly to see harm over time or have a large dose exposure at one time to have physical symptoms. Typical everyday exposure should cause no issues. Oh, and this report mentioned that 2,4 D is part of Agent Orange, too – scare tactic by chance?? I mean the AAP must know just because one chemical combined with another may be toxic, it doesn’t mean that chemical by itself has the same toxicity. They must realize that, right?? Dicamba has its issues and has been in the news because of volatilization and off-target movement, harming other crops. But like 2,4 D, when used appropriately dicamba also may be applied without special risk. Like all agricultural chemicals, dicamba undergoes routine reassessment review as part of the EPA’s ongoing monitoring and reassessment of new research over time. Both these chemicals are commonly used around personal homes and recreational areas as well as in agriculture.
Regardless, it is of utmost importance that parents, landscapers and farmers use any chemical judiciously and per the instructions on the label to limit undue risk. When used appropriately, the chemicals the report references don’t have any worrisome toxicity that should make us sound the alarms. Interesting to think of it that way actually – just like a doctor might think about appropriate use of prescription medications. What a parallel!
Worries about too much
Next, after worries are laid out about specific chemicals, the clinical report moves on to state unease over heavy or repeated application of herbicides to GE crops. Let me tell you a secret before we go deeper into this worry: Glyphosate (or any chemical) comes with a cost to farmers. Pesticides cost money, they cost time, application puts wear and tear on equipment, and improper application could affect future crops – do you think farmers want to overuse these chemicals after considering all these costs? If you do think farmers are just spraying pesticides at will, then please read on as chemical use turns out, is done with lots of caution, planning, and expert consultation.
How is glyphosate (or any other pesticide) applied then, you ask? I am not an expert in this area, so I consulted with a plant scientist along with several farmers to learn more. Turns out farmers routinely consult the chemical label instructions to ensure safe and effective applications. They also have agronomists and agricultural extension agents who know the soil and the crops to help come up with an appropriate plan. Furthermore, many farmers hire professional pesticide applicators to do the job most efficiently. This professional applicator will consider environmental conditions, timing of applications and appropriate dosing to get the job done right. The timing of when a pesticide is used may also allow a farmer to only spray one application to a field to get the full benefit – really! Additionally, glyphosate is sprayed on crops as the plant is starting its growth. For corn and soybeans, it is sprayed when the crop is young, before any ears of corn or soybean pods are even present on the plant.
Agricultural chemicals are used in very calculated amounts and applied precisely to crops – modern spraying equipment is incredibly accurate and allows farmers to spray a chemical to within inches of their target. The volume of glyphosate typically used is what would fill about two cans of pop (or beer if you’d rather) and is mixed with a large volume of water (hundreds of gallons) and finely spread over an area the size of a football field. Let’s say that again – two cans of pop spread over an area of a football field. And glyphosate is what is called a foliar herbicide. It only works if it is applied to leaves, so anything hitting the soil is wasted. Farmers apply a small amount, a fine mist, to a canopy of unwanted plants – not exactly a heavy soaking. We often hear about farmers “dousing” fields with chemicals – does this sound like “dousing?” Just like doctors use prescription medication with caution, farmers use pest control with caution and only when needed, for their own safety and the safety of their families, their land, and their crops.
The clinical report then tries to double down on our chemical fears by telling us about heavier applications of herbicide used to combat resistance. Let’s clarify this: If you have a resistant weed problem, you might be able to overcome it with a heavier volume of use. But this is not often done. Instead, farmers again consult with their local agricultural extension agent or agronomist to determine the next best option for effectiveness and safety. Farmers don’t want to have to use unsafe levels of chemicals used for their own land’s safety and their own personal and family safety. Let alone wasting money on a treatment that won’t work anyway.
To give credit where credit is due, the authors were correct in pointing out the emergence of glyphosate tolerant weeds, which has become a problem. Like the overuse of antibiotics can lead to problems in health care, the reliance on a single strategy for weed control also forces selection of weeds that grow through the herbicide unabated. This is a concern most scientists and crop specialists predicted and are working on, and unfortunately is a residue of a cheap and effective weed control strategy.
Glyphosate: How it works
Let’s get to the good part, how glyphosate works. Glyphosate is what’s called a competitive inhibitor of the enzyme 5-enolpyruvalshikimate 3-phosphate synthase, or EPSPS for short. The enzyme is not found in animals, which is the basis of its limited toxicity. Inhibition of this enzyme prevents plants from making some amino acids, and without amino acids to use, the plant slowly dies. Genetically engineered plants are equipped with a special version of the same enzyme that does not bind glyphosate, so they continue to manufacture aromatic amino acids in the presence of the herbicide and continue to live. What happens post-mortem once the weed has died, you ask? Well, glyphosate breaks down in the soil into ammonia, inorganic phosphate, and carbon dioxide – these byproducts are also not dangerous.
But wait – here is the kicker!! EPSPS synthase is only found in plants and some microorganisms. EPSP synthase is NOT found in animals or humans. This therefore means glyphosate has no known mechanism of action in humans or animals. It is almost all excreted from our bodies when it is ingested. The pharmacological fate of this molecule, coupled to the low residue exposures, means there is virtually no risk from occupational or dietary exposures. But I know you can’t wait to hear more, so, let’s continue (just to be thorough).
But what about residues???
Next, there’s lots of hullabaloo about glyphosate (and other pesticide) residues. The paper talks about how when people eat organically grown foods (which reject the science and benefits of genetic engineering), detectable glyphosate residue levels in our urine go down. What?! Not eating residues of a certain chemical means you’ll find less of it in my urine?? I know. Shocking.
Here’s the breakdown of this revelation: when glyphosate residues are found in our food or urine, they’re found in minuscule amounts. Amounts hundreds of thousands of times below the level of concern. The parts per billion (and sometimes parts per trillion) they find are akin to talking about seconds of time in thousands of years. And honestly, finding glyphosate in my pee tells me my body is doing a great job of auto-detoxing by peeing out this chemical my body can’t use! What is interesting, is that the authors dwell on the fact that the compound can be detected, but they never discuss the relative risk of levels detected. They continue to raise concerns about levels that have never been causally connected to any risk, in laboratory animals or epidemiological study of populations.
By the way, if you’re wondering how much residue you’d need to ingest to cause harm, this nifty “Pesticide Residue Calculator” calculates (based on most recent Pesticide Data Program data) how many servings you’d need of a particular food to ingest dangerous pesticide levels for kids and adults. Spoiler: the results show that you’d need to eat volumes of food that would burst your stomach before you’d have any effects from pesticides. 2300 bowls of cereal anyone?
Additionally, the EPA conducts yearly monitoring of pesticide residues via this Pesticide Data Program. It consistently finds that 95-99% of samples have no residues or residues far below levels of concern. Of note, they test for conventional pesticides, but organic pesticides are given a pass and are not routinely monitored. So, no one really knows how much organic approved pesticide residues are on our food. Pesticide residues (organic or conventional) can also be rinsed off (rinse with water, no soap, don’t scrub and damage the outer produce layer!) prior to eating which makes an even lower level of exposure for the consumer. To their credit the AAP does mention this rinsing trick, but it is hidden between all the other fearmongering.
The dose makes the poison
Pesticide residues (glyphosate or otherwise) on our food are consistently monitored and found to be well below levels that would cause health effects – let alone that some pesticides such as glyphosate don’t even have any known action in the human body. The studies the authors present showing urinary exposure have two flaws: the first being that exposure doesn’t equate to toxicity (as they even mention) and that the volume detected reflect exposures hundreds of thousands of times below the acceptable daily intake level for glyphosate. These tolerance levels are set with a wide margin of safety – anywhere between 10-100x below the level at which an effect is observed (more info can be found here and here). As that AAP is a group of health care providers, I’d like to remind them that we calculate appropriate medication doses for our patients to avoid toxicity all the time – this is the same concept!
Glyphosate and cancer… or not
Beyond residue detection, the clinical report’s next biggest concern is the carcinogenicity of glyphosate. The AAP totally missed the memo on this one. The IARC designation for glyphosate as a probable carcinogen has been consistently criticized by the scientific community since it came out in 2015. The IARC designation is hazard based, and they reached their conclusion based on non-statistically significant trends and omission of data not supporting the narrative. At the time of its determination, the IARC left out a significant study (the 2018 Agricultural Health Study “Glyphosate Use and Cancer Incidence in the Agricultural Health Study”) that would not have supported this carcinogenic label. In fact, the head of the IARC review group was found to have knowingly left out this data that would have changed the group’s carcinogenic designation. This means even though the IARC came up with this label, it was not a thorough appraisal of all the information that this AAP report makes it sound.
The designation of glyphosate as carcinogenic was an outlier, as Dr. Steven Novella writes. And while emotional court cases are raking in massive paydays for law firms using the IARC designation, no other organizations have supported labeling glyphosate as carcinogenic. Organizations like the American Medical Association (AMA), the World Health Organization and the United Nations Food and Agricultural Organisation (FAO), the European Food Safety Authority, the National Toxicology Program, the US’s Environmental Protection Agency (EPA) and even Health Canada state there is not enough evidence to support the notion of glyphosate carcinogenicity. To continue to show the authors’ bias and agenda in this pediatric clinical report, they fail to cite Andriotti et al. (2018) – the largest and oldest cohort analysis of applicators – as a report conflicting with their claim of carcinogenic associations. This work has followed 54,000 applicators over more than two decades and shows no association between glyphosate and non-Hodgkin lymphoma.
The selective omission of this study that does not support their narrative is deeply concerning. The AAP report authors instead cite studies such as Zhang et al (2019) to try to prove their points. This meta-analysis jams together data from previous papers that are not directly comparable. The paper suggests a 41% increase in risk of non-Hodgkin lymphoma (20 cases per 100k to 28 cases per 100k). However, the work has been highly criticized because associations were only seen when comparing highest exposures and time points and were generated only when data were inappropriately combined.
As you can see, the science does not support this carcinogenic label whatsoever. The 3 articles cited by the AAP only show associations without confirmed causation. Numerous additional research studies have not confirmed this worry. All this shows us this report not only spreads misinformation, but this gross misrepresentation and omission of the body of research on the topic is concerning for intentional covering up of the facts. The authors of the AAP report cite only papers that support their fear-based message and leave out conflicting studies and peer-reviewed criticism by cancer epidemiologists. Selection omission is poor scholarship.
Fearful recommendations about food hurt our patients
The downstream effects of this clinical report in a respected journal will not only result in confusion amongst healthcare providers and parents, but even worse it will make the public fear perfectly healthy food options. We have research showing that when consumers fear conventionally grown produce, but they can’t afford (or don’t have access to) organic options, they SKIP buying that produce all together.
The AAP article suggests buying organic food, which is automatically “non-GMO”, to avoid all these concerns about pesticide exposure. In the same vein, they admit that organic food is consistently more expensive than its conventional counterparts and may not be realistic for some families. Beyond being overpriced, organic food also isn’t accessible to many consumers. Worse, a significant number of rural and deep urban consumers do not even have access to even conventional produce, and now the authors have convinced them it is poison. The added monetary cost plus lack of accessibility plus fear equates to deterring families from eating fruits and veggies all together. This is massively more detrimental to public health than the ingestion of exceedingly low levels of pesticide residues on our foods.
The organic myth
Beyond the harmful side effects of this messaging, organic growing practices can (and do) use pesticides – why, then, aren’t we worried about these organic pesticides? What’s more risk, a synthetic poison or a natural poison? Should we not be calling for more research on organic pesticides as they are less closely monitored? Let’s remember, a chemical being natural versus synthetic tells you absolutely nothing about its toxicity. And in case you’re thinking the recommendation to try buy organic food is based in its superb safety or nutrition compared to conventionally grown products, we have yet to see consistent research that has shown any real health benefits of organic options.
Beyond these facts, the environmental impact of growing foods for the masses with organic methods uses more land and resources to get the same yield as conventional methods. You can see more evidence of the concerning environmental impact of organic food here, here, here and here. All this is to say, the organic label’s health halo isn’t as shiny as it might first appear. It is a classic example of an appeal to nature. The recommendation for people to seek it out is just plain elitist. A costly virtue signal. No thanks AAP, I’ll save my clinical recommendations for things that really matter.
Fearmongering about ultra-processed food and high-fructose corn syrup
After they finish telling us how risky pesticide residues are, the authors shift to fearmongering about ultra-processed food (UPF) and high-fructose corn syrup (HFCS). The AAP here wants us to tell families they should limit UPFs in exchange for minimally processed (and organic) produce. They also hope this will limit ingestion of HFCS – the poor sugar with the bad rap. Come on, AAP, HFCS is just a version of sugar that our bodies process the same way as other sugar versions. Just because HFCS is present in processed foods doesn’t make it bad. And UPFs aren’t what they make them sound like either – they keep using this term, but I do not think they know what it means – read more here and here.
The food standards being set in this AAP report are not helpful. We all know that we need more fruits and veggies in our diets. But instead of lecturing us on what to avoid, it would have been better if the AAP authors gave us tips and ideas on how to help us incorporate produce options into our daily lives in a realistic manner. Enough food shaming already! For some families, UPFs are foods a child with disabilities requires – you going to tell me our g-tube formulated nutrition (which is ultra-processed!) is bad because of that processing and presence of HFCS? Or that the autistic child who has food aversions should instead go hungry? Processed food may be all a family can make work for them. This reflects so powerfully on the stark reality of some people’s food insecurity. How dare we make people fear food that may worsen meeting this basic human need. It would have been refreshing for the AAP to instead offer a plan to help families work with that they have.
To be fair, the authors of the clinical report do state the importance of talking with families and taking into account unique and realistic food options for each family and guiding them with this in mind. But while they do make these appropriate points, when given in the context of a clinical report that is otherwise making people fear food unnecessarily, it creates a massive disconnect in their message. They say in their introduction that pediatricians can, “minimize fear-based messaging” but then proceed to scare people for the rest of the piece. Basically, they’d like me to tell families there are “risks” to eating GE and non-organic and ultra-processed food but then say, “but it’s OK if those options are all you can do.” How is a family supposed to take that?? Instead, how about we just counsel on the wealth of good food options in all forms that can help make up a balanced diet for people of all ages, abilities, and economic statuses.
Pot, meet Kettle
While I have tried to address the concerns in the clinical report, I need to say a quick word about the additional “parent education” piece on the topic. As if things weren’t bad enough already, this accompanying article touts the same fears and inaccurate information. But what I found funny in this parenting article was how they tell parents to be wary of misinformation. They state, “Social media posts and news stories may shrug off the dangers of GMOs…” To this I’d like to say to the authors, take your own advice! You omitted research that didn’t agree with your conclusions so you could keep with your fear-based message. You used sources that have been wrong for decades about genetically engineered crops. You are the ones that need to read the evidence. YOU need to do better.
What’s to be done?
As an AAP member and physician, I have an obligation to stay current on the state of the science and help families understand risk. When the internet and mommy groups are rife with false information and conjecture, pediatricians (and all physicians) have a key role in connecting families to the realities of empirical data and the best peer-reviewed research. It is eerily similar to anti-vaccine rhetoric when a leading organization manufactures a highly publicized, visible, and shared article that misinterprets risk, promotes false claims, and shows horrendous scholarship. Pediatrics might as well be promoting that the childhood vaccine schedule causes autism. Our credibility as a reliable source of healthcare information is at stake. Yes, the disinformation, selective citation, omission, and bias are that bad.
Pediatrics should commission and publish a critical review of the review or retract the work altogether. The bell of fear has now been rung – and that is hard to undo. This makes our jobs as pediatricians and our role as science communicators even more challenging. But if the AAP can help work to right their wrongs, it will support us all in continuing to fight misinformation and unfounded fears.
In ending, I’d like to offer thanks to several members of the science community who offered me confidence and additional education as I wrote this piece. They helped me present this topic in adequate breadth and with scientific accuracy. For that, I am truly grateful.
Want additional supporting articles showing flaws in the IARC designation?
Epidemiologic studies of glyphosate and cancer: a review, Regulatory Toxicology and Pharmacology Journal, June 2012
Exposure to glyphosate and risk of non-Hodgkin lymphoma and multiple myeloma: an updated meta-analysis, La Medicina del Lavoror Journal Italy, Feb 2020
Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers Journal of Environmental Science and Health, Mar 2016
Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies” Critical Reviews in Toxicology, Mar 2015
Glyphosate epidemiology expert panel review: a weight of evidence systematic review of the relationship between glyphosate exposure and non-Hodgkin’s lymphoma or multiple myeloma, Critical Reviews in Toxicology, Sep 2016