Glyphosate and Anencephaly: Death by A Thousand Cuts

Anencephaly, which occurs when the rostral (head) end of the neural tube fails to close early in embryonic development, represents perhaps the most extreme manifestation of neural tube defects (NTDs). A wide range of developmental events and processes, working singly or in concert, are either known to cause, or are strongly associated with, NTDs in general, and with anencephaly in particular. Glyphosate is the most widely used herbicidal chemical on the planet. Here we review a multitude of ways in which glyphosate can detrimentally impact, or ‘cut,' embryological and fetal development to specifically favor the anencephalic phenotype. The evidence presented here includes data gathered from epidemiology, toxicology, general and nutritional biochemistry, and developmental biology. While the case here is often based on statistical associations and plausible biological arguments, we offer clearly defined pathways whereby glyphosate can be seen as likely holding the knife that is inflicting some, or perhaps even most, of these developmental cuts that lead to anencephaly and other NTDs. We offer some suggestions for lines of research to validate or refute our thesis, and conclude with our thoughts on the relevance of this link with regard to public health policy.