Several years ago I was going to write a post about Roundup and glyphosate, its active ingredient, but decided against it because several very good science-based reports were produced by others. Unfortunately, those reviews were not directed towards gardeners and based on frequent discussions on social media, the message is still not getting through to the gardening community.
My goal in this post is not to do my usual deep dive into Roundup, but instead I want to give readers a summary overview of the facts along with references containing more details. I hope that putting all of the information in one spot will make it a useful tool for discussions in gardening social media groups.
Roundup vs Glyphosate
Roundup was originally produced by Monsanto and it contained glyphosate as its active ingredient. Most people recognize and use the name Roundup. Unfortunately, Monsanto (now Bayer) has decided that since this brand name is so well known, they could use it to promote other products, some of which don’t even contain glyphosate.
One Roundup product marketed in Europe is vinegar with no glyphosate, and some products contain both glyphosate and another herbicide.
We really should be talking about glyphosate and not Roundup.
Roundup and Monsanto
Conversations that go something like this, “Roundup is toxic because I hate Monsanto” are illogical.
If you hate Monsanto – that is fine. But your love or hate of the company does not change the chemical properties of glyphosate. One has nothing to do with the other.
Does Glyphosate (Roundup) Cause Cancer?
The general public is more convinced than ever that glyphosate (Roundup) causes cancer because of the recent court cases. I’ve discussed this in detail in Roundup (Glyphosate), Cancer and the Courts.
The result of a court case is the sum opinion of the jury, and it does not represent the scientific facts. There is no doubt that the majority of general public hate Monsanto and Roundup, and they truly believe Roundup causes cancer. But that belief does not make it true.
One of the largest agricultural human heath studies has been following workers using glyphosate, for 20 years, and reported, “Overall rates of cancer in the study remain lower than in the general population, especially cancers of the oral cavity, pancreas and lung.”
The science is quite clear on this, there is no evidence that glyphosate causes cancer and most global health and safety organisations agree. The following infographic was prepared by the Genetic Literacy Project, a group promoting truth in science.
The EU Joins the Group
Update: July 26, 2021. I just saw a report from the EU (European Community) that reviewed the science on glyphosate. This 11,000 page report, looking at over 20,000 studies, concluded that glyphosate is safe and does not cause cancer. The only danger they found was that glyphosate “causes serious eye damage”.
Why is this significant? The EU has banned glyphosate in many applications, on a purely political basis, but the average person used this as “evidence” that glyphosate was harmful and caused cancer. It is good to see that the EU scientific community has finally done a proper review. Hopefully, governments will now catch up with the science.
Glyphosate (Roundup) and GMO
A common argument agaisnt GMO plants is that it encourages the use of Roundup. These two issues are unrelated to one another.
Yes, there are some Roundup-ready GMO crops. But the majority of GMO plants have nothing to do with Roundup and they are not Roundup-ready. See GMO Myths – Understand the Truth About GMO Plants for more details.
You can be against Roundup and be for GMO.
Glyphosate (Roundup) Found in Drinking Water and Babies Milk
Studies have found glyphosate in drinking water and in mothers breast milk. The headlines claimed that this was a huge problem, but when you look at the details you realize that it’s a non-issue.
It’s all about the dose.
Our scientific instruments are so good these days that we can find just about any chemical in water and milk. I reviewed the report that found glyphosate in Spain’s drinking water and calculated that you would need to drink the equivalent of 1,000,000,000 bottles of beer, on a daily basis, in order to reach an unsafe level.
The levels found in the environment and in mothers milk are extremely low and of no health concern.
Glyphosate (Roundup) and Chronic Diseases
Some claim that glyphosate causes all kinds of diseases including, diabetes, neuropathies, obesity, asthma, infections, osteoporosis, infertility, birth defects and non-celiac gluten sensitivity. Many of these claims have been made by Samsel and Seneff.
Anyone who has followed the Roundup debate will recognize the name of Dr. Stephanie Seneff. She has made numerous claims about glyphosate which are quickly discounted by the scientific community “as outrageous use of science”. Dr. Seneff is a computer programmer with no experience in chemistry, plant science or health science. Her most recent claim is that glyphosate is a contributing factor of COVID-19.
Unfortunately, the general public eats up her publicity stunts.
A recent review of the claim that glyphosate causes chronic diseases found no support for the claim and went on to say “Our critical analysis of the commentaries published by Samsel and Seneff reveals that their conclusions are not substantiated by experimental evidence but are based on a type of failed logic known as syllogism fallacies. As Nobel Prize-winning theoretical physicist Richard Feynman famously said, “It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.””
Glyphosate (Roundup) and Soil Microbes
It is commonly believed that glyphosate harms soil microbes. When glyphosate was added to soil it was found that “it was rapidly degraded by microbes, even at high application rates, without adversely affecting microbial activity.”
Glyphosate (Roundup) and Gut Bacteria
Numerous recent reports in the media and online claim that science has demonstrated glyphosate affects our gut bacteria, and if true could have serious health implications.
One of the reasons glyphosate is so safe is that it only affects a well understood biochemical pathway called shikimate, which is found in plants but not animals. This is the reason it is not toxic to animals. The shikimate pathway is found in some bacteria that live in our gut.
A recent study claims to have shown that glyphosate can affect these bacteria.
Marc Brazeau is the editor of Food and Farm Discussion Lab and is the Genetic Literacy project’s senior contributing writer. He has done a thorough review of the report claiming a link between glyphosate and gut bacteria and found that the data did not support the conclusions.
The study itself does say, “more studies will be needed to ascertain if there are health implications arising from glyphosate inhibition of the shikimate pathway in the gut microbiome”. The study did not reach any conclusions about glyphosates effect on our health, even though the news reported it with sensational headlines.
Another study found that even levels 50 times larger than the Accepted Daily Intake (ADI) set by European food safety agencies had very limited effect on gut bacteria.
Glyphosate (Roundup) and Bees
A study sprayed honeybees with a normal concentration of glyphosate and found no harm to the bees.
Some studies have looked at bee behavior after exposure to glyphosate, and have reported some learning disabilities in bees. The number of bees studied was very low, and 1/4 of those were lost during the study. Other studies have looked at exposure to very high levels of glyphosate.
Bees certainly have environmental and pest problems, but glyphosate has not been shown to be one of them.
Facts About Glyphosate
Here are some important facts about glyphosate.
- our skins absorb very little
- it undergoes very little metabolism in the body and is mostly excreted
- it has a very low toxicity; the oral LD50 in rats is 4320 mg/kg, significantly less than vinegar
- it quickly adsorbs to soil and becomes inactive
- it has a soil half-life of 50 days, which is short for a pesticide
- plant uptake from soil is minimal
Not Enough Testing!
The anti-Roundup movement is quick to claim that there has not been enough testing, and that the existing testing was done by labs hired by Monsanto. That is nonsense. Over the last 45 years there have been thousands of studies by labs all around the world.
At some point you have to accept the results.
Holy crap, I can’t believe that at this point it’s not common knowledge that glyphosate has had the most toxic effects ever. Even worse than DDT and you should know how that played out. Get back to what’s natural and stop poisoning everyone.
Sure. And how many people do you wish to starve?
Look how much food places that don’t have access to the chemicals our farms use produces.
So are you offering not to eat?
And where can I find the OECD-Comlliant study that shows the “…most toxic events ever.”?
Also, at what dose do we see these effects?
The compliant studies show no adverse effects until the dose exceeds 175mg/kg/day, and the actual exposure limit is 1mg/kg/day n
Heavy use of Roundup Concentrate spraying football field size grounds over and over again 4 year after year under the gallons a month or year will definitely cause cancer
Did you not read the post? This has been studied thousands of times and there is no such evidence.
There is actually a LOT of evidence, which you conveniently decided to omit completely from your article. You cherry-picked Samsel and Seneff’s work—which, yes, is flawed—but ignored a great number of other studies showing a link between glyphosate and non-Hodgkin’s lymphoma in particular. Furthermore, you have also neglected to mention the controversy surrounding Monsanto covertly funding many of the studies which show no harmful effects of the substance.
To suggest that the science is clear on this matter is negligent, and makes your piece come across as propaganda rather than “busing myths”.
“you have also neglected to mention the controversy surrounding Monsanto covertly funding many of the studies which show no harmful effects of the substance.”
This is brought up a lot. They may have funded some studies, but do you really feel that they paid off every one of the thousands of scientists that made a study on this? And they they need to pay off all of the reviewers of these studies.
The work of Semeff and Samsel is beyond flawed, it’s completely worthless. They do nothing but propose hypotheses and then never test them experimentally to see if they can be validated.
As for the other studies, which of them show a causal relationship between glyphosate exposure at or below the ADI and NHL that comply with the standards and GLP in toxicology?
You won’t be able to do so, as all the compliant studies show no significant increased risk at the current limits (for review see Griem et al. 2015).
Glyphosate has been with us for 40 years or more …parts per million will not harm anyone ..what is forgotten in all this is how safe the product is compared to what it replaced in farming of yesteryear..
This is something the general population does not understand. The pesticides we used 40 years ago were much more toxic. In fact, when Europe banned the use of Roundup, many farmers returned to more toxic products, and people were fine with it, because they don’t understand.
Hi everyone
Roundup kills life. Last time I looked I am part of life.
The farmers need to use roundup to make a living. So the producers can produce cheap food. Maybe it’s time to give everyone a decent wage so they can buy good healthy food.
I don’t want one company owning all the crops and having the ability to make billions from something like food. I like to be able to have choices.
I have a garden also and don’t use roundup. Not because it’s good or bad because we just don’t no for sure. There just so many different views. I just find it enjoyable tilling up my soil and getting on my hands and knees pulling the unwanted weeds. I no my vegetables taste different than the ones I get from the store. Maybe it’s time we get back to the basics.
Stay safe stay strong stay healthy
You certainly launched a storm of gobbledegook there Robert. Thanks for article, especially knowing some of the responses it would generate
To Jo B. You are correct, it’s the Surfactant – Ethoxylated Tallow Amine that contains Ethylene Oxide a Class 1 Carcinogen. Other Industrial Surfactants have entered foods and vaccines such as Polysorbate 80(PS80) thus more exposure to Ethylene Oxide.
The problem is not the effect of glyphosate on humans. There are too many of them already. It kills “weeds” and so destroys the food of all the other creatures in our world. Go and look at the sterile “countryside” outside your garden.
Nobody is spraying Roundup on wild fields – it costs money. They spray it on fields that are used for agriculture and the weeds will be destroyed one way or the other. Before Roundup we used much more toxic chemicals, but we still killed the weeds.
You are part of the problem. I got glyphosate poisoning wading in farm flood waters . It kills your gut biome. Causes autoummune diseases. My liver is fried. Who are you kidding??
Your statement is completely false – You simply can’t get poisoned this way.
I’m happy I read your opinion about Roundup. My gardener uses it and my concern was growing to the point I wanted him to stop. I have to say, I’m so tired of being a ping pong ball of conflicting opinions that keep a person on the edge of fear. I know I don’t have ugly weeds in my yard any more. This isn’t a gardening question but, you and your readers seem so knowledgeable. Is this coronavirus as bad as we’re told,to the point of wearing masks?
It is a matter of you deciding you do or don’t want to meet the virus, and the possibility of you meeting it and spreading it to people you love who may be more vulnerable than you. It is HIGHLY contagious. The WORLD wide struggle should be your clue. You filter your coffee, your vacuum, and the oil in your car. The more layers of filtration/separation between each of us the lower the transmission rate. The degree of filtration will be determined by: the material your mask is made of, how clean you keep it, how well it fits your face, how well you avoid touching its outer surface (where “germs” will accumulate), and how much you are exposed to other people. You do not know who is carrying it. Yes, wearing the mask is a socially responsible thing to do because it will MINIMIZE transmission and is something we can all do. (My background is that worked with deadlier and more contagious zoonotic viral diseases and quarantining of exotic animals on a day-to-day basis for 15 years in a zoo and three biomedical research universities and never took my work home with me…I am not an epidemiologist but managed these facilities and kept my staff safe)
How about these super weeds that are becoming resistant to Round-Up? Farmers are getting very frustrated with that. Also, why would Monsanto pledge 4 billion to creating a “safer” herbicide if it’s perfectly safe and safe to drink? I don’t think so and I welcome you to sip down a glass if that’s what you believe. Just the track record of Monsanto makes me hate them for their crimes against humanity. There is absolutely a connection between the stuff and non Hodgkin’s lymphoma but no cancer causing properties proven. Most of these studies have been doctored by Monsanto themselves to make their product seem safer. Answer why their factory employees must wear PPE equipment but it doesn’t say to on the bottles? It’s malice that Monsanto are guilty of here. They knew all along and had the money to cover up any bad findings about their product. They have our own EPA in their pockets! And don’t get me started about the tainted drinking water in Sri Lanka that got over 20,000 people sick from it running off into their water supply. And it’s safe to drink. Right. Look that one up once. Carey Gillum and her book Whitewash is pretty compelling. Yes, I believe billion dollar companies like Bayer/Monsanto can get away with anything. More private studies need to be conducted!!!
Fun fact for you.
I can point to 7 studies that fully complied with the OECD-453 (Combined Carcinogenicity and Chronic Toxicity) protocols (For review see Griem et al., 2015; Monsanto 1990, Cheminova 1993, Feinchemie Schwebda 1996, Arysta LS 1997, Syngenta 2001, Nufarm 2009).
These were conducted by industry, academic, and government groups in the US, UK, Italy, Poland, India, and Japan. Despite not sharing researchers, the results were all successful replications of the OECD methods, and combined with the reams of additional studies (OECD, EFSA, and EPA variants), shows that we see no increased risk of any negative health effects when the exposure is below 175mg/kg/day, let alone the level of the ADI (1mg/kg/day).
I find it endlessly amusing that you claim that Monsanto doctors studies, when they are the only side of this who has actually adhered to the basic standards in toxicology, and HAS replicated their results.
How many studies that meet the minimum requirements in toxicology for determining that a causal relationship exists between glyphosate exposure and any adverse effects at or below the current limits?
Zero
The OECD protocols have been the standard for decades, yet in all that time, not one study has come out of the anti-biotech groups, while industry, academic, and government labs have managed this precise feat time and time again.
The best part?
It’s those anti-biotech researchers who have severe issues replicating their results.
This also shines a very damning light on those researchers, as I can point to a perfect example of the “ethics” displayed by researchers you probably fawn over.
The first combined study on glyphosate reported by Monsanto back in 1981 was fully compliant with the standards when it was begun, but by the time it was finished (104 week study), the OECD protocols had been adopted as the new standard, and the study was missing some key elements relating to the MTD, sample size, and treatment groups.
So the study was not compliant with the new standards. We’ll come back to this in a moment.
In 2012, the infamous “lumpy rat study” (Seralini et al., 2012) was published…and quickly eviscerated by the scientific community, as it was a botched design from start to finish. So much so that I have, and will continue to use it as a teaching example on how not design a study.
He took a protocol (OECD-408), which is normally used for a 14 week duration, used half the minimum number of rats per treatment per gender, bumped the duration to 104 weeks, plus used a line of rats (Sprague-Dawley) that is genetically predisposition to develop those large tumors 80% of the time after 18 weeks.
In other words, the study was not compliant with the current standards in toxicology.
So how did those involved respond to the deficiencies in their studies?
Monsanto went and ran a new 2 year study that was fully compliant with the OECD-453 design (Monsanto 1990).
Seralini did nothing, and to date NO ONE has been able to replicate his findings.
Reality casts a very different light on this topic, and you might want to actually learn about how things work in toxicology, because you clearly have no clue, and an axe to grind in relation to Monsanto.
Oh, and correlation is not causation, nor can it be used to imply causation. There’s a reason why my peers and I devote so much time and energy to developing methods to test for causation, and it’s because correlative associations rarely pan out as being causally linked.
Yea. And you could drink out of a pond that’s never had. A man made chemical in it. And still die of beaver fever.