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.
Unfortunately your article did not address the effects of Round Up on DNA. There have been many studies that don’t paint a pretty picture.
https://www.sciencedirect.com/science/article/pii/S0278691518304800
An incomplete article but it looks like it made some people feel good.
Br safe.
…did you actually read the paper in full, or just the abstract?
You do know that they took isolated PBMCs, and then exposed them to formulated RoundUp…which contains surfactants…which are generally called soaps…that disrupt lipids…like those that make up cytoplasmic membranes of those PBMCs, right?
We’ve been using soap for millennia because it performs this very task, and you’d get the same results if you swapped out RoundUp with Dawn dish soap.
Mammalian cells do not fare well when treated thusly…and the methods used didn’t come close to meeting the standards in toxicology for determining genotixicity (OECD 2015 Guidance Document).
If it’s safe to drink, can you make a video of yourself drinking it? Thanks.
My opinion is that it’s not safe most people don’t even wear gloves or masks,my neighbour was using it all the time to kill weeds I even asked her why she didn’t wear a mask or gloves and she just said it’s just a weed killer, she was 39 and eventually died of aggressive stomach cancer they had to remove her stomach,I still think it was from using that hideous roundup it should be banned.
One thing that in’s never mentioned is that herbicides including Roundup have limited effectiveness. Weeds will grow back after several weeks or months in the same area. It is like a dog chasing it’s tail. I use Sunday weed killer which is a herbicidal soap but only where I can’t pull or dig them.
New weeds might grow back, but glyphosate is every effective on most plants.
I am a chemical engineer by education and worked at the US Patent Office as a patent examiner for 8 years in chemical pharmaceuticals and then worked at the USDA agricultural research service as a patent writer and a technology transfer coordinator for thirty years.
I also have been gardening for twenty years.
I personally do not use non natural products in gardening.
Your vociferous support for glycophosphate I find extreme. Your comparing it to materials that are on the GRAS list (generally regarded as safe) I find inappropriate. It is not a GRAS material.
I donate food I grow and will not put such a manufactured chemical on it – out of respect for the recipients and their various knowledge levels.
Your acknowledgement of surfactant issues shows that the overall content of your article is not well written for the general audience as many lack the understanding of the effects of the other compounds that are typically combined with this active agent.
My thoughts.
Your article highlights so much of the problems with man made chemicals and is so short sighted of all the effects these products have not only on human health but the health of the entire environment it’s used in. You already backed up what bothers many people which is unnatural chemicals in our drinking water and bodies! We as a supposedly free people should have the right to decide what goes into our own bodies whether or not it’s been deemed safe or not at the current moment. We as humans are part of a linked ecosystem dependent on each other and having private companies patenting life forms and spreading their products not only through you spraying something from a bottle but the accumulation in our water, soil, seeds and air. I wonder if you ever spent years nurturing a piece of land and all the plants, insects and wildlife that inhabit it?? The blowback you get is from these very people who have intimate relationships with the land and earth and they don’t need Scientific evidence to prove to them what they see on a day to day basis! These products are created to support monoculture growing which we are now are seeing the Scientific evidence that shows how destructive this is to our ecosystems. You should perhaps reference the work of Vandana Shiva about the effects Monsanto’s products and business model had on the Indian farmers as well as farmers around the world. This problem goes so much deeper than just Glyophosphate! Sometimes it’s the other ingredients that make a chemical able to be sprayed are the problem. My advice to you is get your hands dirty and stop trying to convince people who know we can grow and eat food, just as humans did for thousands of years without products that make a few greedy people rich!!!!
You do have that option. Grow your on food. Grow it however you wish to.
But the plan truth is. With out chemicals the number of farmers that are out there making food. Could not grow enough to feed the world.
Its use chemicals or a lot of people starve.
Refreshing to hear a reasoanable, educated voice amidst the noise. Thank you, and keep putting the truth out there.
Anyone who wants accurate info on this topic should research Dr Vandana Shiva. The scientific research is available to show this article to be misinformation. If someone is espousing that roundup can be ingested has not done the proper research.
Hi Robert, Excellent article. I do want to make one addition. Glyphosate was never detected in breast milk by any credible test. The group that posted this has a history of notoriously bad science, and their claims were never peer reviewed or replicated. To the contrary, Dr. Shelley McGuire is an expert in breast milk and her analytical chemistry team knew how to detect glyphosate using the most sensitive tests. She detected none. The method and the results were published in two peer-reviewed articles.
After publication she was harassed and vilified by activists. Her scientific results didn’t match their beliefs or their crusade. She became the victim of online slander and FOIA requests. While not surprising, it is shocking to see researchers attacked because they simply did good work.
Thank you – I’ll have to have a closer look at that.
Thank you for this great fact based article. Don’t let the dummies get you down