Glyphosate and Sperm: Just How F-ed Up is Roundup?
How the World’s Most Common Weed Killer is Messing with Your Sperm
Glyphophosate and sperm – whatnow?
Here’s some advice nobody needs: don’t drink Roundup if you want kids.
You’re probably thinking, “if I want kids? How about if I just want to live? Doesn’t that stuff give you cancer?”
We’ll get to that—the answer is weirder than you’re expecting—but we’ll lay the groundwork first. Till the soil, if you will. (This article is about agriculture, so that counts as a joke.)
The Facts on Glyphosate
Fact #1: “glyphosate” is the active chemical in Roundup and other popular brands of weed-killing pesticide spray. That makes it the most common pesticide in the world, with a total global use of about 800,000 tons—roughly 2.5 Empire State Buildings’ worth of liquid chemical death. Very metal, but potentially a little concerning given that…
Fact #2: glyphosate is not super good for you. See part 2 of this article. It mucks with the human nervous system, probably affects our hormones, probably causes human cancers, and definitely damages sperm.
Fact #3: glyphosate…might not even be all that useful.
In technical terms, glyphosate is a type of chemical called a phosphonate, and its big achievement is that it interferes with the normal functioning of a plant enzyme called EPSPS. EPSPS has nothing to do with attracting cats (cat people will get that joke). We did check, though. Instead, it makes a bunch of the amino acids that plants need for their cells to function, so when glyphosate gets in there and does its thing, the plants just die.
It’s used to kill weeds, but it’ll also kill any other plant it touches—grains, fruit trees, vegetables, whatever. What made its discovery in the mid-70’s so exciting was that we were also able to genetically engineer important crops—like soybeans—to use a different enzyme than EPSPS. That meant farmers could spray roundup indiscriminately over their fields like a new plant owner desperately spraying water on their dying garden.
That setup…led to some problems. The Organic Center estimates that Roundup Ready crops (the ones described above that were genetically modified to withstand Roundup exposure), by making it so easy to use the herbicide, increased global glyphosate use by 383 million pounds. And that was a decade and a half ago.
Plus, mass spraying of Roundup has prompted some weeds to evolve into SUPER WEEDS that, like our genetically engineered crops, are resistant to the herbicide.
Worse still, we know it’s getting into our bodies. The use of glyphosate is supposed to be safe as long as farmers follow the EPA pesticide label (the guidelines for safe use, basically), which include rules like not using more than 2 gallons of it per acre per year, and not spraying it so heavily that it starts running off the plants and into the ground.
Those rules aren’t working. Last year, a big study of glyphosate levels in the urine of Idahoans living near farms found that they were much higher during spraying season, meaning that glyphosate was getting off the fields and into their food, water, or air.
That means we have to confront the big question: what is glyphosate doing to us?
Rounding Up the Evidence on Health
So, there’s some serious scientist drama going on here. Most of the big national environment agencies are still okay with Roundup and its glyphosate-containing cousins. The EPA’s on board, the European Food Safety Authority is fine with it (mostly), and so on.
The International Agency for Research on Cancer (IARC), though, is not. They said that,
For the herbicide glyphosate, there was limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma. The evidence in humans is from studies of exposures, mostly agricultural, in the USA, Canada, and Sweden published since 2001. In addition, there is convincing evidence that glyphosate also can cause cancer in laboratory animals.
The EPA reads this, freaks out, and shoots back:
EPA did not agree with the International Agency for Research on Cancer (IARC) conclusion that glyphosate is “probably carcinogenic to humans.” EPA considered a significantly more extensive and relevant dataset than the IARC. […] For instance, IARC only considered eight animal carcinogenicity studies while EPA used 15 acceptable carcinogenicity studies.
This is the boring-science-report version of a blood feud and there will probably be a slap fight at the next conference.
The dispute is probably nonsense, though—for the most part, both of these things can be true. That’s because the EPA and IARC teams were asking different questions. The EPA looked at industry studies of almost-pure glyphosate in real-world conditions. The IARC looked at publicly available studies of off-the-shelf products and checked what happens when something goes wrong, leading to higher-than-allowed exposure.
In other words, Roundup almost certainly does cause cancer—and kills large numbers of brain cells and probably messes up our hormonal systems—if you’re exposed to enough of it, but it may still be safe in extremely limited amounts.
What Was That About Sperm?
There’s one area, though, where the evidence is not conflicting: sperm health. Glyphosate is bad for it. Most of the data we have are still from animal models—meaning we did horrible things to mice again—but it’s pretty convincing. Sperm motility goes down along with sperm concentration, and the barrier separating the testicles from your general bloodstream gets weaker, so it’s harder for them to produce healthy sperm.
We do have some human data, and it’s scary: sperm motility goes down even just one hour after exposure to glyphosate.
Worse, being exposed to glyphosate in the womb has epigenetic effects that reduce sperm quality and sperm creation over the course of your life. That brings us full circle, right back to where we started. If you want to be a dad, stay the hell away from Roundup. Spraying a little in your backyard isn’t going to make you infertile, but it is a serious health risk, it is a meaningful fertility risk, and regulation is lagging behind the science. In other words, maybe consider some slightly more natural weed-killing options.
