Fact 1: Glyphosate is the active ingredient in the world’s most common agricultural herbicides.
Fact 2: The mechanism that glyphosate uses to kill plants is the same mechanism by which it kills the beneficial bacteria and yeasts found in the human microbiome that are necessary for good health.
Fact 3: Glyphosate consumption has been shown to cause disruptions to the microbiomes of farm animals, which subsequently lead to disease in the animals.
Fact 4: Glyphosate cannot be washed off or peeled away, and it is found in food containing non-organic produce and grains.
Open Question: Has glyphosate entered our food supply in quantities significant enough to be causing increased rates of those diseases that are linked to disturbances to the human microbiome?
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Previous articles published here on healthygutbugs.com have emphasized how unhealthy microbiomes are correlated with and are contributing to a variety of health problems such as obesity, anxiety, allergies, picky eating, irritable bowel syndrome and even autistic behaviors. We’ve discussed how antibiotics can have a devastating effect on our guts by indiscriminately killing beneficial bacteria that live inside of us (known as probiotics or commensal bacteria) in addition to killing disease-causing bacteria.
The vacant real estate left in the gut after the antibiotics have done their job in carpet-bombing bacteria of all kinds, allows resilient microbes, which were unaffected by the antibiotics (such as certain yeasts or antibiotic-resistance bacteria), to increase their numbers and outcompete the previous residents. The subsequent stronghold of these reinforced microbial colonies makes it then more difficult for the probiotic (good) bacteria to recover and recolonize the gut following a round of antibiotics. This altered resulting composition of microbes in the digestive tract can cause long-term adverse health effects.
This unintended side effect of antibiotics is now well-known and is being increasingly understood as an emerging area of study for public health.
But, what’s less well-known and understood is the comparable potential health risk that chemical herbicide residues in our food supply may pose. Could first-world modern agricultural processes that produce majority of the world’s food supply be posing a similar, or even greater threat to the health of our microbiomes?
An alarmist blog post written on the Healthy Home Economist blog, which made the rounds on social media, has claimed that an insidious hazard to our microbiome exists in 80% of the American food supply. The article asserts that glyphosate (the active ingredient in Roundup – the most popular herbicide on Earth), widely used by the vast majority of commercial agricultural in the United States and beyond, is absorbed by plants such as the wheat grain, and can never be washed off. There, it enters the food chain, which the author believes has triggered a dramatic increase in the number of people who have difficulty digesting wheat or who have become allergic to it. There are further suggestions that the prolific growth of gluten intolerance is related to the assertion that glyphosate has entered the food supply. The article further states that glyphosate can kill beneficial microbes in the digestive tract, thereby creating an environment that permits more harmful ones to survive and thrive.
Although there is a legitimate question about the validity of many of the claims made by the author with respect to the extent of Roundup’s use in farming and its prevalence in our food supply, there is some peer-reviewed, scientific evidence supporting that at least one of its statements is likely true. Glyphosate itself has been scientifically shown to have properties that are capable of harming helpful commensal microbes in the human digestive tract.
The implication is that that this ubiquitous pesticide could pose a potential threat to our microbiome if it is in fact getting into our food supply (a topic itself which is still under debate). When commensal bacteria are killed, they are no longer able to perform their health promoting functions, such as preventing allergies and auto-immune reactions, thus harming human health in ways that we are only now just starting to understand.
What is Glyphosate and how does it Work?
Glyphosate is a weed-killer capable of killing most plants. Roundup, which has glyphosate as its primary active ingredient, is designed to kill plants, other than those that have been specifically genetically modified by Monsanto, Bayer and other companies be resistant to the herbicide. Glyphosate prevents the plant from being able to make proteins required for it to grow. Glyphosate works by disrupting an enzyme pathway (the shikimic acid pathway) that synthesizes the essential amino acids phenylalanine, tyrosine and tryptophan, which plants and some microbes then use to manufacture particular proteins that are necessary for the plant (or gut microbe) to grow. After the herbicide is applied, the plants yellow up and die over the course of several hours up to several weeks.
Roundup is applied to food crops that have been genetically modified not to be harmed by it. Common “Roundup Ready®” genetically modified crops include corn, soy, canola, cotton, sugar beets and alfalfa, which are found in a significant portion of the American food supply. Farmers buy special seeds to plant crops resistant to glyphosate, so that when they spray for weeds, their genetically modified crops will thrive while the undesired weeds will wither away.
Additionally, glyphosate is used by many home gardeners to fight weeds. The herbicide is frequently sprayed in public places such are parks and sports fields to keep them looking groomed and tidy, as well as on backyard vegetable gardens to help with weed control.
Glyphosate is also applied on non-genetically modified food crops prior to harvesting, in a process called desiccation, to make the harvesting process easier for the farmer. In the desiccation process, farmers spray their crops with glyphosate. This has three benefits. First, it brings the crops to maturity when they are unable to on their own because of rain or other poor growing conditions. Second, it facilitates crop drying, which makes harvesting more productive as it’s easier to harvest wheat from a dry dead stalk than a wet live one. Finally, it removes all weeds for sowing the next crop. Because glyphosate is thought by farmers to be safe to consume, this practice is common.
Once sprayed, glyphosate is absorbed by the plant and taken up into its leaves, seeds and fruits. It cannot be washed off or broken down by cooking. Processing certain grains treated with glyphosate can actually concentrate the pesticide residues found in the flour.
Glyphosate use is increasing because Monsanto’s patent on glyphosate in Roundup expired in 2000, which has enabled other manufacturers to also produce herbicides containing it, thus reducing its cost and increasing its prevalence. Additionally, some weeds are starting to become resistant to its effects, requiring larger and larger applications of it during the farming process.
Is Glyphosate Safe?
When glyphosate was first introduced in farming, there was a lot of excitement about it because it was toxic to plants, but was believed to be harmless to animals. There have been many years of study on the safety of glyphosate. Summaries of results of the majority of the research (much of it funded by the industry) seem to show that it is safe for human tissue. There have been some other conflicting studies, however, showing it may cause DNA damage and cell cycle dysregulation that can lead to genomic instability and subsequent development cancer. A vocal minority of scientists and activists remain concerned about it use, despite published reports that it is safe for human consumption.
Monsanto has claimed in the past that it is safer than table salt. It is rumored that some indomitable Monsanto salespeople have even been reputed to theatrically drink their product to demonstrate how benign it is. But could these safety claims be misleading due to longer-term health implications?
One concern with the safety research and data is that none of the safety studies have been designed to specifically examine glyphosate’s effect on our gut microbiome.
Our gut microbiome is made up of commensal or probiotic microbes, which are bacteria and yeasts that live in and on the human body and provide us with critically important health benefits. If glyphosate has the capability of harming the probiotic microbes residing in our digestive tract, the resulting harm to our microbiome may hurt our long-term well-being by triggering later disease or indirectly contributing to other health conditions. However, the effects from a disrupted microbiome can take a long time to reveal themselves. The scope of the concern starts to become clear when you consider the fact that the majority of cells found within the human body are not human but are microorganism – microbes outnumber human cells by 10 to 1.
Although it is pretty clear that the acute toxicity of glyphosate to humans is low (i.e. you can drink it with no immediate ill effect), the chronic toxicity, which only reveals itself over many years and after multiple exposures, may be much higher because of the herbicide’s actual impact on the human microbiome. (Then again, maybe not. This article is merely suggesting that further study is merited.) From a scientific perspective, it can be extremely challenging to confirm whether a chemical, ingested with food, is the cause of chronic diseases that present themselves many years later. Conducting a long-term, controlled study with humans as the “lab rats” would be neither practical nor ethical.
Why does it Matter if My Gut Microbiome is Disrupted?
Medical science is starting to learn how important our commensal microbes are. They play a critical role our immune system, neurological system and our digestive system. These commensal bacteria aid in digestion, support and train the train the immune system and impact human behavior. They also help to directly disarm some of the toxins in food as well as making it more difficult for other harmful substances to enter the body by strengthening the lining of the digestive tract. Without commensal microbes to assist the body in clearing them, toxins that are ingested can cause greater harm. Research into this area of medicine has exploded.
Additionally, our gut microbiome helps to reduce inflammation. When an unhealthy mix of microbes develops in the gut, inflammation can be the result. Chronic inflammation leads to other illnesses. Disruptions to the microbiome have been linked to many disorders that are often associated with the developed world such as gastrointestinal disorders, allergies and asthma, obesity, diabetes, heart disease, depression, anxiety, autism, obesity and perhaps even Alzheimer’s disease. “Negative impact on the body is insidious and manifests slowly over time as inflammation damages cellular systems throughout the body,” says a researcher who has looked at the effect of glyphosate on the microbiome.
What Effects does Glyphosate Have on our Microbiome?
Preliminary research has shown that glyphosate can directly kill commensal microbes. A peer-reviewed study in the journal, Entropy, examined the effect of glyphosate on microbes in the human gut. It found that the microbiome is affected by the herbicide and goes on to argue that it may be one of the primary causes for many of the chronic diseases seen in the Western world.
The shikimic acid pathway, mentioned above as being the chemical pathway that glyphosate attacks when it kills plants, is also present in algae, bacteria, fungi and yeasts. When glyphosate disrupts this pathway, it prevents the organism from producing essential amino acids that it needs to live and grow. Our microbiome is made up of primarily bacteria and yeasts. Hence the shikimic acid pathway is also present in the microbes that make up our microbiome. So if these beneficial microbes come in contact with the glyphosate, they too can be killed by it in the same manner that weeds are.
Disruptions to the gut microbiome caused by glyphosate and resulting ill health have been observed in both the cattle and poultry industries for many years. A Germany study outlined the toxic effects that glyphosate exposure had on beneficial microbes in cattle digestive tracts. The study’s authors concluded that the resulting disruption to the normal, healthy microbiome was the explanation for the increased cases of botulism that arose in exposed cows. A different study on poultry showed that glyphosate, even at low levels, had an extremely disruptive effect on the microbiomes of the chickens by reducing the beneficial bacteria and permitting harmful, disease-causing bacteria (Salmonella and Clostridium) to increase their numbers. Enterococcus, Bifidobacterium, Bacillus and Lactobacillus, each of which has multiple beneficial health effects for humans, were shown to be very vulnerable to glyphosate exposure.
Is Glyphosate found in our Food Supply in Significant Amounts?
Even if glyphosate has the potential to harm our microbiome in significant ways, it would not likely pose a material threat to human health if it did not get into our food in significant amounts.
Unfortunately, and quite surprisingly considering the fact that it is sprayed on food crops in ever-increasing volumes, there are very few statistics on how much glyphosate actually remains in our food supply after harvest and processing. We simply do not in fact know how much is being ingested.
Because glyphosate has been considered safe, neither the United States Food and Drug Administration (FDA) nor the Unite States Department of Agriculture (USDA) monitor levels of it found in food!
An independently funded study looked at soybeans to see if there was glyphosate in the edible part of the plant. Three types of soybean crops were examined: 1.) Roundup Ready® (genetically modified to be resistant to glyphosate); 2.) non-Roundup Ready® seeds with conventional farming techniques (that included glyphosate); and 3.) certified organic soybeans. Glyphosate was not found in the organic soybeans. It was found in significant levels in both of the other crops. Surprisingly, it was found in the highest levels in the 2nd group. This is perhaps because Roundup was used as a desiccant in farming, meaning it was sprayed on the crops just prior to harvesting to remove weeds and to dry up the crop to make the soybeans easier to harvest.
Industry-funded studies have shown low levels of glyphosate in in the eggs, milk and the liver and kidneys of farm animals that had been feed with grains treated with the herbicide.
Roundup is the most commonly used herbicide in Europe. A study funded by Friends of the Earth Europe looked at the levels of glyphosate in subjects’ urine, to look for evidence of whether it was getting into the human body. The study examined the urine of people from 18 European countries and found glyphosate in 44% of the samples. Another study on city-dwellers in Germany (i.e. people with no direct contact with glyphosate as part of the farming process) found glyphosate in all of their urine at levels higher than permitted by the E.U. to be in drinking water.
Notwithstanding the fact that glyphosate has been proven to enter the food chain when it is applied on crops, the US Environmental Protection Agency (EPA) quietly increased the levels of glyphosate that were permitted by the governing agency to be in the food, effective May 1, 2013. The acceptable levels for oil seed crops (sesame, flax, and soybean) was doubled from 20 parts per million (ppm), to 40 ppm. The permissible levels for vegetables were increased up to 25 times! For example, for carrots the permissible levels of glyphosate were raised from 0.2 ppm to 5 ppm. These increases were petitioned for by Monsanto because increasing amounts of the herbicide are required to kill weeds because they are becoming resistant to it.
Glyphosate can kill health-promoting microbes in our microbiome by attacking a chemical pathway they share with plants. Glyphosate is in our food chain and enters the digestive tract, thus coming into direct contact with our beneficial microbes that live there. Therefore, it is entirely possible that Roundup and its active ingredient glyphosate are impacting the mix of microbes in our bodies. A healthy microbiome is imperative for optimal health, so alterations to it are cause for concern.
While this article could easily be viewed as an accusation of actual health issues caused by widespread use of glyphosate in mainstream agriculture, it is important to be clear that in fact we simply do not know. As more is being learned about the importance of microbial health for human health and well-being, it seems reasonable to expect that previous assumptions and studies about chemical safety should be revisited to include an evaluation of their effects on the human microbiome. This is what we believe and the purpose for writing this article. The dots have not been connected, but the pattern is indeed concerning.
We feel that it is vitally important that food safety studies are performed to understand how much of this chemical (and probably many others) we are consuming in a typical Western diet. Given the extent of its use on core staples of the American and western diets, it seems clear that a lot of our food is contaminated by glyphosate.
Although privately funded studies are attempting to address this question, large-scale, government-funded research is necessary to get at the truth. Given the FDA and the USDA’s current stance, that glyphosate is entirely safe, this research is not coming anytime soon. And, as someone who is cynical about the political powers that corporations have been given with recent Supreme Court rulings, I personally fear that incentives in Washington D.C. are not totally aligned with interests in public health. Let’s hope that activists can bring this topic the attention it deserves, and move this public healthy issue to mainstream consciousness.