Medical Examiner

You Don’t Need to Worry About Roundup in Your Breakfast Cereal

No one wants to eat Monsanto’s weed killer. But a new report dramatically exaggerates the danger of the trace amounts detected.

A bowl of uncooked oats beside a metal spoon.
Photo by Markus Spiske on Unsplash.

No one wants a breakfast that is contaminated with weed killer. And in particular, no one wants to give their children a breakfast that is contaminated with weed killer. That’s why a new report suggesting that popular breakfast products like cereal, granola, and oatmeal contain “unsafe” amounts of “the Roundup chemical” (glyphosate) are garnering attention from both news outlets and worried parents alike. “The Roundup Chemical Found Responsible for Cancer Might Also Be in Your Oatmeal,” warns Mother Jones. “Report: Oatmeal, Breakfast Foods Contain Unsafe Amounts of Weed Killer,” worries the Detroit Free Press.

The stories all stem from the same report released Wednesday by the Environmental Working Group, titled “Breakfast With a Dose of Roundup?” The report—which was simply published to the internet, rather than in a scientific journal or after peer review—makes some rather outlandish claims about toxicity, glyphosate, cancer, and breakfast. Read without context, it would understandably worry any human who likes carbs in the morning, but when you drill down into the evidence, there is really no reason for alarm.

The problem, as is always the case when considering toxicity, is dosage. Any substance’s potential to cause harm is directly related to how much of said substance you consume; at a high enough dosage, anything can be harmful, and at a low enough dosage, even “harmful” things can be consumed without causing harm. This is why regulatory bodies assess the threshold at which potentially harmful chemicals actually become dangerous and then set regulations for those thresholds.

The Environmental Protection Agency has done this for glyphosate, the chemical in the Monsanto weed killer Roundup that is at the center of the Environmental Working Group’s report. The EPA threshold, which was set in 1993 (so no Trumpian interference to worry about), is 2 milligrams per kilogram of body weight per day (140 milligrams per day for the average adult). That’s the reference dose that’s considered safe to consume daily throughout a lifetime. None of the foods tested by EWG passes that threshold—they don’t even come close.

EWG, on the other hand, argues that the acceptable threshold is actually 0.01 milligram per day, total. That’s an extreme difference. So why did EWG lower the threshold so dramatically? The explanation is published, once again, on the EWG website. The organization arrived at its number by taking the state of California’s recommendation for a glyphosate threshold, already less than one-hundredth of the EPA threshold, and dividing it by 100 again. EWG justifies this second cut by relying on the Food Quality Protection Act, which suggests that an additional tenfold margin should be applied to pesticides to account for the increased risk to children and infants. (The Food Quality Protection Act doesn’t mention glyphosate once, and it’s not clear its recommendation is meant to apply to the EPA standard for the chemical, which is set to factor in body weight.) Even if you apply that extra tenfold factor to the EPA threshold, all the foods tested would still be safe.

Basically, the EWG threshold has to be set at one ten-thousandth of what the EPA has deemed to be safe for the trace amounts of glyphosate to register. Your mileage may vary, but I trust the math of the government agency over the advocacy group that made these hilariously incorrect charts.

Let’s talk about what that means in terms of how much cereal you actually eat. The EWG threshold of 0.01 milligram per day translates to a maximum of 160 parts per billion, given an assumed serving size of 60 grams, which is about 2 cups of cereal or ¾ cup of oatmeal. The parts per billion detected per food sample tested by EWG range from 10 to 1,300. So, yes, some of them cross the EWG threshold. None crosses California’s threshold, and none crosses the EPA threshold. In order to cross California’s very conservative threshold, you’d need to eat 7½ cups of the worst kind of oatmeal a day. In order to cross the EPA threshold, you’d need to eat 100 times that. You or your child would more likely get sick from simply eating hundreds of cups of cereal a day before you’d get sick from glyphosate.

Again, it’s understandable that, at first blush, the EWG report sounds alarming. No one wants to inadvertently feed themselves or their kids something that might be harmful. But the organization’s messaging feeds off chemophobia. An EWG press release on the matter includes the line, “Simply stated, there is far too much glyphosate in their [General Mills’ and Quaker’s] products for parents to feel comfortable feeding them to their kids,” which is frankly manipulative. It also contains the gem, “Just because a pesticide level is legal in food doesn’t mean that level is safe,” without offering any real science suggesting that the levels offered by the EPA or California have been proven to be unsafe. (This isn’t the first time EWG has made outlandish claims about food safety; its annual “dirty dozen” list of fruits and vegetables has also been subject to warranted scrutiny.)

That brings us to the final wrinkle in all of this, which is that years of research increasingly suggests that glyphosate may not pose the cancer risk to humans that we originally thought. Guy-André Pelouze explored the evolving research and understanding of glyphosate’s risk to humans in Slate in January. In addition to the EPA assessment that the chemical is “probably not carcinogenic,” he wrote:

Last year, the U.N.’s Food and Agriculture Organization and the World Health Organization presented a joint review report on pesticide residue in indirectly exposed persons, including farming and production workers’ families, as well as consumers. The report did not find any evidence of increased risk of cancer from glyphosate exposure. Instead, after having examined the epidemiological evidence of occupational exposures, the report concluded, “Glyphosate is unlikely to pose a carcinogenic risk to humans by food intake.”

The European Food Safety Administration also performed human-exposure studies as part of its assessment of glyphosate. Published in October 2015, their assessment found that the observed risk of cancer in humans induced by glyphosate was very low and the causal links virtually nonexistent.

Pelouze’s story goes deep on the research and its history. He writes eloquently about how difficult it is for people to accept uncertainty when it comes to health, despite the fact that some level of uncertainty is part of any risk assessment. It’s worth reading in full.

At any rate, the evolving science doesn’t mean we should pour glyphosate on our pancakes. But it certainly suggests that the EPA level is a reasonable precautionary level to stick with. So as long as you’re keeping your cereal intake below hundreds of cups per day, you’re perfectly fine.