There tends to be two camps; those that prioritize eating organically whenever the opportunity arises and income allows and those that almost seem to oppose it upon principle and find it all to be a bunch of nonsense. There's not usually much middle ground. Perhaps because of this dichotomy, and the industry sponsored backing of glyphosate, I expected to find the studies and research evenly split down the middle when it came to the teratogenicity of glyphosate. What I found was a lot of hard data confirming my original suspicions that glyphosate is a teratogen and not a lot of factual data proving it is not. Industry seems to spend much of its time and energy focused on the marketing aspect, putting out fires and assuaging people's fears that glyphosate is unsafe for human consumption. In 2005, French molecular biologists Sophie Richard, Gilles-Éric Séralini and their colleagues published a study entitled, Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase after noting that some agricultural workers using glyphosate have pregnancy problems, though the mechanism behind the problems was not yet understood. The scientists' studies showed that glyphosate acts as a disruptor of cytochrome activity from concentrations 100 times lower than the recommended use in agriculture and is noticeable on human placental cells (cultured in a Petri dish) only 18 hours after exposure and can effect gene expression. It was found that glyphosate changes androgens into estrogens through a process call aromatization. Its effects are amplified by the non-active ingredients present in RoundUp, which have been shown to facilitate cell penetration. It was concluded that at high doses (still below the classical agricultural dilutions), glyphosate's toxicity on placental cells could induce at least some reproduction problems.
In September of 2012, Séralini (referenced above) published a paper in the journal, Food and Chemical Toxicology, describing findings after a two year study, most predominantly, showing that rats fed genetically modified corn treated with the herbicide RoundUp (glyphosate is the active ingredient in RoundUp) had a much higher incidence of carcinogenic tumors.
"The study used 100 male and 100 female Sprague Dawley rats, divided into twenty groups with 10 rats each. Ten diets were tested separately on the males and females. The diets comprised 11 percent, 22 percent and 33 percent genetically modified corn (NK603) and the rest standard laboratory rat food; NK603 corn that had been treated with Roundup, also at 11, 22 and 33 percent; and corn that had not been genetically modified, accompanied by differing concentrations of Roundup in the water. A control group was fed 33 percent non-GMO corn; the rest of their diet was standard laboratory rat food."
It wasn't long before the study was attacked with accusations that there weren't enough rats used in the study to have conclusive data and that the type of rat used has a higher incidence of developing tumors anyway. Just over a year later, facing criticism, though the authors refused to retract the infamous study, Food and Chemical Toxicology retracted it citing that it was inconclusive.
Above you can see one of that rats that was found to grow tumors after being exposed to glyphosate. The controversial retracted study can be viewed here.