Glyphosate has been all over the news recently after being detected in our food supply. What is it? Why is it in our food, and should we be concerned? What impacts does glyphosate exposure have on human health?
Glyphosate has been in and out of the news cycle for years now. The most recent rash of reporting indicated that glyphosate could be detected in many popular breakfast cereals. As long as this herbicide is used, humans are going to be exposed to it. What does the research actually say about glyphosate? Let’s find out!
But first, what is glyphosate?
Glyphosate has been used as an herbicide in the United States since 1974. It kills a broad range of weeds and grasses making it a desirable choice for a variety of crops. It works by inhibiting a plant enzyme. Because of this, it can’t be used effectively to pre-treat a field, and needs to be used on actively growing plants. After application, it binds to soil and eventually degrades. The half-life, or amount of time it takes for half of the applied glyphosate to degrade, can vary depending on farm conditions and location. The average half-life, however, has been suggested to be about 45 days.
How are humans exposed to glyphosate?
As a broad-range herbicide, glyphosate is prevalent. It’s used everywhere from large farms to a person’s front lawn. Human exposure can happen at a variety of points in the use of this herbicide. First, during the application process a human can be exposed. Before it dries, humans and animals that come into contact with recently applied glyphosate can be exposed. Since it’s used on edible crops, residues can also be found in our food supply. There are two very important things to keep in mind as we talk about exposure: dose and type. The amount a person comes into contact with matters, as does how they came into contact with it (breathing it in, skin exposure, ingestion, etc). The good news? Ingested glyphosate passes through our bodies in our urine and feces. Thanks, body!
Is glyphosate dangerous to human health?
Glyphosate has been used for decades, making it one of the most widely studied herbicides on the market today. Despite this, however, clear cut answers are relatively challenging to draw. There are a few reasons for this: first, the majority of the research done involves agricultural exposure. Agricultural exposure involves the people who are actively working with glyphosate. Understandably, the exposure level will be much higher in those directly working with the herbicide than those of us potentially coming into contact with it through food. Research around human consumption is essentially non-existent. Basically, it’s not ethical to force humans to consume high doses of herbicides for science. In fact, the majority of the research we have around ingestion comes from animal models which are notoriously difficult to draw solid conclusions from. Basically, humans and mice aren’t the same. Who knew, right?! Research is further complicated because crops are often treated with a variety of different herbicides and insecticides, not just glyphosate. This makes it challenging to separate what might be causing what. Remember when I said to keep the dose and type of exposure in mind? That’s going to be important for the next couple paragraphs.
Does our food supply contain glyphosate?
Yes. Due to its widespread use, glyphosate residues can be found on many fresh fruits and vegetables as well as grain and cereal products and other foods. The important thing to remember here is the dose. Before approving any pesticide for use, the Environmental Protection Agency (EPA) establishes a limit on how much residue can remain on food products. When residues exceed the safe levels set by the EPA the food products are seized by the Food and Drug Administration (FDA) and not allowed to reach consumers. The FDA regularly tests foods to ensure pesticide residues are below the safety thresholds. How close are residues getting to safe levels? Not very. In 2016, the FDA tested 760 corn, soybean, milk, and egg samples for residue. Over half (53%) had no detectable pesticide residue at all. None of the milk and egg samples contained detectable residues, and the corn and soy samples that tested positive for residue were well below the safety threshold.
What is the safe ingestion level of glyphosate, and are we at risk of exceeding it?
Both the Food and Agricultural Association (FAO) and World Health Organization (WHO) have set the daily acceptable intake of glyphosate at 1 mg/kg body weight. In 2017, the EPA wanted to find out averag intake of Americans. To do this, they analyzed what exposure would be like, assuming that 100% of the crops consumed were treated with glyphosate. They even calculated any possible exposure via water consumption. The results? The population at highest risk of exposure, those aged 1-2, were exposed to 0.228 mg/kg/day of glyphosate. This is well below safe exposure of up to 1 mg/kg/day.
Can we avoid glyphosate in our food supply?
Probably not. Much of the fear-mongering suggests that non-GMO or organic produce are glyphosate-free. Unfortunately, this just isn’t likely. First, even non-GMO crops may be treated with glyphosate to speed up the harvesting process. Even organic foods are likely to come into contact since it bonds with soil, and soil travels. Exposure might be less, but there’s really no way to avoid it entirely.
So, do we, as consumers, need to be concerned about glyphosate?
Based on my personal research and opinion, and the research and opinions of highly regarded scientific organizations around the world (FAO, WHO, EPA, FDA, and more): probably not. All of these agencies have concluded that there’s no research to suggest that glyphosate exposure through food increases risk of cancer or other detrimental health effects. Residues are regularly tested, and even with the highest possible levels of consumption, are well below the safety threshold. Plus, our bodies are really good at excreting things we don’t need: like glyphosate.