Does Glyphosate Have A Negative Effect On Thyroid Health?
Published June 15 2015
Glyphosate is the active ingredient in the herbicide Roundup. It is used primarily on genetically modified crops, and can be a big factor in the increased prevalence of chronic health conditions, including thyroid and autoimmune thyroid conditions. If you are eating any type of processed or refined foods then there is an excellent chance that you are being exposed to the negative health consequences of glyphosate.
Many reading this are familiar with Monsanto, as they are a corporation who is the leading producer for Roundup, and also produces genetically engineered seeds. An example of this is “Roundup ready soybeans”, which are soybeans that were made to be resistant to the effects of Roundup. In other words, Roundup kills everything with the exception of the genetically engineered crop. While this might sound like a good idea to some people, the problem is that these crops contain high levels of glyphosate, which as I mentioned in the opening paragraph, can lead to chronic health conditions.
But why is glyphosate used on these crops if they can potentially cause chronic health problems? There are a few reasons for this. The main reason of course has to do with making a large profit. It’s unfortunate that some businesses will do whatever it takes to make a lot of money, even if it means risking the health of millions of people.
What Does The Research Show With Regards To Glyphosate?
Neurotoxicity and oxidative stress. There is evidence that glyphosate can lead to neurotoxicity and oxidative stress. One study conducted on rats showed that Roundup might lead to excessive extracellular glutamate levels and glutamate excitotoxicity and oxidative stress (1). In other words, Roundup can cause excessive levels of the neurotransmitter glutamate, which in turn can cause damage to the neurons. Another study showed that glyphosate can cause toxicity to the cells, oxidative effects and apoptosis on human cells (2). Yet another study showed that inhalation of glyphosate may cause DNA damage (3).
Cardiovascular health. Glyphosate might also have a negative effect on cardiovascular health, leading to direct cardiac electrophysiological changes, conduction blocks, and arrhythmias (4).
Breast cancer. There is evidence that low and environmentally relevant concentrations of glyphosate possesses estrogenic activity and can induce the growth of human breast cancer cells (5). This of course doesn’t mean that glyphosate will cause breast cancer in most individuals exposed to it, but it might increase the risk in susceptible individuals. As a result, while everyone should try to minimize their exposure to GMOs, those with a family history of breast cancer might want to make a greater effort to avoid these foods.
Liver detoxification. Glyphosate can inhibit cytochrome P450 (6), which plays an important role in detoxification. I spoke about this in greater detail in my blog post entitled “Understanding The Detoxification Pathways“. In this post I discussed the role of the cytochrome P450 enzymes. These enzymes play an important role in the production of bile acids (7), and so glyphosate also can disrupt bile acid homeostasis (7), which can be one reason why many people have gallbladder issues. There is also evidence that disrupting the production of bile acid can also promote the toxic accumulation of the mineral manganese in the brainstem, which can cause or be a contributing factor to conditions such as Parkinson’s disease (8).
Mineral deficiencies. Glyphosate is a chelating agent, as studies show that at physiologically relevant pH levels, copper and zinc can be relatively strongly complexed with glyphosate, whereas iron, calcium, magnesium, and manganese are complexed to lesser degrees (9).
Gut dysbiosis. One study looked to determine the impact of glyphosate on potential pathogens and beneficial members of poultry microbiota (10). The study showed that highly pathogenic bacteria such as Salmonella and Clostridium are highly resistant to glyphosate, while most of the beneficial bacteria were found to be moderate to highly susceptible. Another study showed that glyphosate had an inhibitory effect on some of the good bacteria in the gut, but increased the population of pathogenic species (11). In other words, glyphosate can lead to intestinal dysbiosis by killing the good bacteria, while not harming any bad pathogens which may be present.
Glyphosate Affects More Than Our Food and Water Supply
Although the primary concern when it comes to glyphosate is the impact it has on the food we eat, there are other concerns as well. For example, some studies show that glyphosate can have a negative impact on honeybees (12). The results suggested that glyphosate at concentrations found as a result of standard spraying can reduce sensitivity to nectar reward and impair associative learning in honeybees. I know that some reading this might not think this is too big of a deal, but while many people realize the problems that herbicides and pesticides cause with regards to our food and water supply, most people have a tendency to overlook the harmful impact of herbicides and pesticides on other areas of our environment.
Glyphosate is Even More Toxic When Combined With Other Chemicals
One of the flaws of many research studies which tests for the toxicity of different chemicals is that they frequently will test these chemicals individually. The problem with this is that most herbicides and pesticides, as well as other chemicals (i.e. household cleaners) include multiple chemicals, which when combined make the product even more toxic. For example, most of these pesticide and herbicide formulations also contain something call adjuvants, which are labeled as being inert by most manufacturers. Roundup doesn’t only include glyphosate, but it also includes ethoxylated adjuvants, which makes the formulation even more toxic than if it only included glyphosate alone (13). In other words, while glyphosate alone can cause health issues, the combination of glyphosate with these adjuvants makes it even more toxic.
Another issue with most of the research studies regarding certain chemicals has to do with the frequency of exposure and duration of the studies. For example, one can make the argument that consuming genetically modified foods on an occasional basis might not be as bad as eating genetically modified foods every day, which many people do. In addition, if someone were to eat genetically modified foods daily for one year, this probably would be worse than eating genetically modified foods daily for three months. Don’t get me wrong, as eating these foods daily for three months might cause health issues, but the point I’m trying to make is that it’s very easy to manipulate the findings of research studies, as if they do a study and determine that a pesticide formulation causes obvious health issues after one year, they can easily design another study that only lasts six months and therefore demonstrates no health conditions.
And that’s a big issue with many of the research studies out there with regards to toxic chemicals. Most of them are short term studies, and most of these chemicals are tested individually. But in most cases people are exposed to these chemicals for many years, and as I mentioned earlier, most of these formulations include more than one chemical.
Glyphosate and Thyroid Health
There are a few different ways in which glyphosate can impact thyroid health. First of all, lactobacillus converts inorganic selenium into more bioavailable forms such as selenocysteine and selenomethionine (14). However, lactobacillus is negatively impacted by glyphosate (15), which in turn can lead to a depletion of selenomethionine and selenocysteine. Numerous studies show how selenium plays an important role in thyroid health, not only in the formation of thyroid hormone (16), but numerous studies show how selenium can help to lower thyroid antibodies (17) (18) (19).
In addition, having a leaky gut and intestinal dysbiosis are also factors with regards to thyroid autoimmunity. I already mentioned how glyphosate can cause intestinal dysbiosis, but there is also evidence that glyphosate can disrupt the barrier properties of intestinal cells (20). In other words, exposure to glyphosate might cause a leaky gut in some people, increasing their risk of developing an autoimmune condition such as Graves’ Disease or Hashimoto’s Thyroiditis.
So hopefully you have a better understanding of the potential risks associated with glyphosate. The research shows that glyphosate exposure can lead to numerous health conditions. Glyphosate is mainly used on genetically modified crops, and so if you are eating any processed or refined foods then there is a pretty good chance you are being exposed to this chemical. Plus, keep in mind that in the herbicide Roundup, glyphosate is combined with ethoxylated adjuvants, which makes it even more toxic. Glyphosate can impact thyroid health by decreasing the bioavailability of selenium, which can potentially cause intestinal dysbiosis and/or a leaky gut, which in turn can increase the risk of developing an autoimmune thyroid condition such as Graves’ Disease or Hashimoto’s Thyroiditis.