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The Case Against Glyphosates
The End of Roundup?

It isn’t often that a scientific paper is published that has the potential to turn the world upside down but that is the case for the paper with the informative but baroque title: “Glyphosates’ Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases by Anthony Sempsel and Stephanie Seneff It is available on the web at:


In this paper the authors Sempsel and Seneff detail biological mechanisms through which glyphosate may be contributing to a  plague of biblical proportions. Glyphosate is, of course, the
active ingredient in Roundup, the herbicide that is used on 80% of the genetically modified crops grown in the United States.

Roundup ready corn and soy are routinely dowsed with Roundup to kill off any weeds that may have infested the plantings. The fact that evolution is creating super weeds that are no longer killed by Roundup is a familiar story but it is not the subject of Sempsel and Seneff’s paper. Instead they describe ways in  which exposure to glyphosate can contribute to Obesity, Autism,  Alzheimer’s disease , Parkinson’s disease, and digestive issues to name just a few of the diseases that have seen epidemic increase in the years since GMOs were introduced. How is it possible that glyphosate might be the causative agent in these epidemics when since its introduction it has been touted as safe?

The argument made by Monsanto is that glyphosate kills plants by targeting a biochemical pathway that is crucial for plants but absent in animals. It is called the Shikimate pathway and it is important for the synthesis of the aromatic amino acids phenylalanine, tryptophan, and tyrosine. What Sempsel and Seneff point out is that this pathway is present in the gut bacteria and so glyphosate acts as an antibiotic, killing off the beneficial bacteria that perform many essential
biological tasks. It turns out that we are none of us the rugged individuals of Republican lore. Foreign cells (bacteria) outnumber our own cells by a factor of 10 to 1 and it is more accurate to think of a human being as a communist (gasp) society of mutually dependent creatures than an isolated collection of human cells.

The diseases I’ve mentioned like Autism and Alzheimer’s are only imperfectly  understood and you might wonder how Sempsel and Seneff can make the connection between glyphosate and these diseases given this difficulty.

The answer is that although these diseases are not completely understood they have been the subject of much scientific study. Each of the diseases is associated with a host of biological markers — measurable disruptions in the biochemistry that correlate well with the presence of the disease.

Sempsel and Seneff have done an exhaustive search of the literature to identify these markers (the paper has about 300 references) and much of the original research involves looking for mechanisms that would account for the markers through the action of glyphosate. This is the heart of the
paper and it is also the part that will be hardest for the non specialist to evaluate. Because of the huge sums of money that are tied up in the Roundup project it will be very hard to separate the signal from the noise in the controversy that their paper is bound to stir up.

Already the authors have been attacked on the web for not having the right credentials to be making believable pronouncements on complex matters of biochemistry. Foolish ad hominum arguments like this one can be dismissed out of hand but there does remain the serious matter of trying to separate Sempsel and Seneff’s work  from the efforts of the numerous cranks and charlatans that infest the web.

Fortunately, the web also comes to the rescue. You can see Stephanie Seneff give
a lecture on this material here.

She is manifestly not a crank. You learn that she got interested in this subject because she had a concern about the autism epidemic (in 1970 just 1 in 10000 children was diagnosed with autism and the figure has since climbed to 1 in 50) and felt that she could make a contribution to  understanding what was going on. She has the dedication to immerse herself in the scientific literature and the brilliance to be able to think biologically about what she was reading.

I would like to say a few words about this last point since in microcosm it is also the difference between  industrial agriculture and organic farming. It has been known for many years that deposits of fat and cholesterol on the arterial walls leads to hardening of the arteries and heart disease. The mechanical prescription to deal with this is straightforward. Reduce the amount of cholesterol and fat in the diet and the raw material for the buildup on the arterial walls will be reduced.

A tremendous amount of harm is done because cholesterol and fat turn out to be biologically essential. The biological way of thinking about this is to recognize that the body never does things without a good reason. The deposits of fat and cholesterol must be solving a problem for the body or it would not be taking extreme measures like depositing the fat and cholesterol in arteries near the heart. If one identifies the problem that the body is solving by making these deposits then one can treat this problem and the body will no longer need to make the deposits.

And here’s the rub. To identify the problem that the body solves requires an intimate knowledge of biochemistry. Stephanie Seneff is really good at this sort of reasoning as you can see by going to her
homepage and reading any of her essays,

In particular if you root around you can find her thoughts on this matter of the hardening of the arteries (I am not telling you where you can find this since I want you to look around her site). Another pair of papers you can find on her site,  offer extensive compilations of epidemeological evidence connecting glyphosate to a host of diseases and biochemical disasters that are too long to summarize effectively.

It is well understood that correlation is not causation but if you can look at the graphs in these papersf and not think something is going on “you are a better man than I am, Gunga Din”.

How does this relate to organic farming? Well, if pests attack a crop the mechanical response if to kill the pest and try to reduce collateral damage. The biological way of thinking about this is to recognize that a crop which has been around for thousands of years must have ways to protect itself from pests. If the pest is succeeding something must be weakening the plant and the trick is to restore the health of the plant. In systems that are as complicated as soil and plants this is more of an art than a science and the lack of a prescriptive formulation is doubtless one of the reasons that organic agriculture is not universally adopted. Sempsel and Seneff’s paper is an illustration of what is  probably an iron law of unintended consequences. Interventions in nature on the basis of a mechanical understanding will *always* result in disaster.

In a rational world the magnitude of the disaster that can be attributed to the use of Roundup would get it banned from the store shelves immediately. In a world where money and power are the deciding factors it will take longer for Roundup to end up on the trash heap of history.

In the meantime the advice of Professor Seneff to eat organic is good but sadly as documented in the recent movie “A Place at the Table” quite a few people in our society cannot even afford to eat the
cheap lousy food that is available in our markets. They will be the guinea pigs to establish
the toxic effects of glyphosate for years to come.

John Palmer is a retired math professor from the University of Arizona.