Just about all of us are aware of Roundup, Monsanto’s ultimate answer to the weeds that plague gardeners and farmers alike. This glyphosate-based herbicide (GBH) is famous for its ability to kill weeds right to the root as shown in this video:
Let’s open by noting that residues of glyphosate-based herbicides are pretty much ubiquitous in our world. Traces of GBH end up in drinking water through rain, surface runoff and percolation into groundwater and are also found in the food that we eat. In fact, this 2014 study found that soybeans that were genetically modified to withstand the application of GBH (i.e. Roundup Ready soybeans) contained glyphosate in both plant leaves and beans whereas there was no glyphosate in soybeans that were either conventional or organic. In some cases, the levels of glyphosate residue were “extreme, far higher that those typically found” as shown on this graphic:
Now that we have that background, let’s look at the study. First, the rats used in the study were divided into two groups; a control group and a group that was given an ultra-low daily dose of glyphosate in their drinking water over roughly a two year period. The daily intake of glyphosate was 4 nanograms (one billionth of a gram) per kilogram of body weight, the same level that is representative of what may be found in contaminated tap water. As well, it is important to note that the level of glyphosate used is well below the global acceptable daily limit.
In the past, it has generally been thought that glyphosate poses minimal health risks to mammals since the biosynthetic pathway that these herbicides use is present in plants and some bacteria and absent in vertebrates. After the rats used in the study were euthanized, their bodies were examined and it was found that the livers and kidneys were the two organs most affected.
Let’s look at the key results:
1.) Male rats appeared to suffer more acute damage to their livers and kidneys and this resulted in an increased rate of premature death.
2.) Roundup treated female rats showed three times as many anatomical signs of pathology in their kidneys and livers than the control group.
3.) A testosterone/estrogen imbalance was detected with testosterone serum levels increased by 97 percent compared to the control group. This suggests that there are endocrine disrupting effects of glyphosate.
Findings from previous studies in which mice were fed diets containing Roundup-tolerant genetically modified soybeans also showed marked increased liver aging among other issues, observations that were backed by this study.
The authors of the study conclude with the following:
It was previously known that glyphosate consumption in water above authorized limits may provoke kidney failure and reproductive difficulties. The results of the study presented here indicate that consumption of far lower levels of a GBH formulation, at admissible glyphosate-equivalent concentrations, are associated with wide-scale alterations of the liver and kidney transcriptome that correlate with the observed signs of hepatic and kidney anatomorphological and biochemical pathological changes in these organs. In addition, as the dose of Roundup we investigated is environmentally relevant in terms of human, domesticated animals and wildlife levels of exposure, our results potentially have significant health implications for animal and human populations. Furthermore, data also suggests that new studies incorporating testing principles from endocrinology and developmental epigenetics, in particular to evaluate the endocrine disruptive capability of GBH/glyphosate, should be performed to investigate potential consequences of low dose exposure during early life as well as in adults.”
With soybeans becoming such an integral part of our diet, whether we realize it or not, and the use of Roundup Ready genetically modified soybeans nearly cornering the market, this study should give us reason to question the growing use of Monsanto’s headline herbicidal product.
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