I do not think that glyphosate, the most widely used herbicide in the world is a chemical from Hell, created by the devil, in other words, Monsanto. I do think that when used as indicated, especially when applied to crops genetically engineered to resist it, glyphosate can make a significant contribution to improving our food supply without imposing an undue risk on the population. I know from past experience that any argument aimed at exonerating glyphosate from the accusations that it causes cancer, autism, arthritis, Alzheimer’s Disease or virtually any other condition one can think of, leads to accusations of being in the pockets of industry and shilling for Monsanto. The only shilling I do is for making decisions based on the preponderance of evidence rather than on emotion, innuendo, hearsay or wild speculation.
Speaking of wild speculation, let me address MIT scientist Stephanie Seneff’s conjecture that glyphosate is an evil substance capable of causing a variety of ailments because of its chemical resemblance to glycine, a naturally occurring amino acid. This notion merits discussion because it has spread like wildfire across the social media.
Glycine is one of the building blocks of many proteins with collagen being a classic example. It is a “nonessential” amino acid, in other words not required in the diet since it can be synthesized in the body from the essential amino acid serine. Seneff is a professor of Electrical Engineering and Computer Science who somewhat curiously pontificates on health issues. She contends that proteins, which are chains of amino acids, can get messed up if glyphosate accidentally gets incorporated into their structure instead of glycine. Not a preposterous notion given that glyphosate is indeed a derivative of glycine. But, and a rather big but, is that there is no proof that this actually happens.
A search of PubMed, the “go to” compilation of the published medical literature reveals no evidence for glyphosate incorporation into proteins or any altered protein function due glyphosate residues. In spite of a lack of evidence, Seneff attempts to link glyphosate substitution for glycine in proteins with diabetes, obesity, asthma, chronic obstructive pulmonary disease (COPD), pulmonary edema, adrenal insufficiency, hypothyroidism, Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), Parkinson’s disease, prion diseases, lupus, mitochondrial disease, non- Hodgkin’s lymphoma, neural tube defects, infertility, hypertension, glaucoma, osteoporosis, fatty liver disease and kidney failure. Sigh. Belief that a single substance can cause such a cacophony of diseases indicates a lack of mature scientific thought.
According to Seneff, even the effects of the Zika virus may be due to glyphosate. She maintains that Zika infections had not been associated with lack of brain development (microcephaly) until recently and suggests that this may be due to the virus now growing in an environment that contains glyphosate. If this gets incorporated into viral proteins instead of glycine, it could be making the disease far more dangerous prenatally than it had been in past decades. A scary notion for which there is absolutely zero evidence.
Another of Seneff’s contentions revolves around “methyl group donation,” a process that involves the transfer of a carbon atom bound to three hydrogens between molecules and is indeed critical for numerous cellular functions. She proposes that while glycine can provide methyl groups, glyphosate cannot, and thereby throws a wrench into the cellular works. A strange contention since a simple glance at the molecular structure of glycine shows that it does not contain a methyl group. In any case, there is no shortage of methyl donors in the diet since methionine, folate, betaine and choline are all excellent methyl group providers.
Seneff climbs further out on a trembling limb by suggesting that glyphosate contamination could explain the connection between vaccination and autism. She claims that the collagen used to culture materials for vaccinations could contain glyphosate instead of glycine if the animals from which the collagen was obtained had been raised with feed containing glyphosate residues. As already mentioned, there is no evidence that glyphosate gets incorporated into collagen, and even if this did occur, there is no evidence that autism is caused by changes in protein structure. The most salient point, however, is that the supposed link between autism and vaccination has been thoroughly debunked.
Why even bother with discussing allegations that basically amount to scientifically bankrupt fear mongering run amok? Because pseudoscientific arguments can sound very seductive to the large segment of the population lacking a sufficient scientific background to evaluate their merit. The result can undue stress as well as be poor decision making when it comes to issues such as diet or vaccination. This is not to say that there are no concerns with glyphosate or that companies such as Monsanto are populated by choirboys who revere honesty above all else. Both opponents and supporters of glyphosate use attempt to spin data to their advantage. And the problem is that these days there is a great deal of data to spin.
For example, one could even claim that glyphosate has an anti-cancer effect as long as one refers selectively to the literature. A study by Tulane University researchers published in the peer-reviewed journal, “Drug Design, development and Therapy” found that glyphosate and its breakdown product, aminomethylphosphonic acid (AMPA), inhibit cell growth in cancer cell lines but not in normal cell lines. The suggestion is that rapidly proliferating cancer cells produce more proteins and have an increased demand for glycine which is normally supplied by conversion from serine by the action of an enzyme. This enzyme has been shown to be inhibited in the presence of glyphosate or its breakdown product, leading to an inhibition of cancer cell growth due to a deficiency of glycine.
Does this mean that glyphosate can actually have an anti-cancer effect in humans? Of course not. The human body is not a giant test tube. But as far as experimental evidence goes, there is at least more substance to this study than to the vapid claims that glyphosate’s structural similarity to glycine is responsible for unraveling the fabric of modern society
Joe Schwarcz PhD is Director, McGill University Office for Science and Society, Montreal, QC, Canada
