It’s no secret that autism concerns are part of the genesis of vaccine skepticism. The story of Dr. Andrew Wakefield is well-known and well-documented. His reports, combined with a general ignorance of scientific method and clinical trials, created a perfect storm that set back public health for a generation or so.
Emotionally, I would like to see him held responsible for his misdeeds. But in the end, I can’t sanction criminal prosecution merely for publishing his “research.” Dr. Wakefield is entitled to a great degree of free speech in this country. The rest of us have to sort out his claims. And that leads me to the story of Dr. Stephanie Seneff.
Dr. Seneff is an MIT-educated electrical engineer who is no doubt a math whiz. And she has taken it upon herself to claim that glyphosate, the active ingredient in Roundup® herbicide, is responsible for the increase in autism cases in the US. Here’s a picture of the dastardly “pesticide”
Looks evil enough, right? But this is one of the greatest herbicides ever invented and is a major reason genetically modified plants can be used in agriculture. It’s considered essentially non-toxic to human beings, but kills plants efficiently. But that word “non-toxic” is loaded. Toxicology is a science unto itself and is subtle. I’ll get to that in another post.
Perhaps over-simplistically summarized, Dr. Seneff’s argument is that glyphosate antagonizes the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), present in plants but not in humans. Dr. Seneff claims EPSPS is present in many human gut bacteria, and this bacteria is inhibited or killed upon eating plants treated with glyphosate. As such, bacteria colonies in our guts are upset, leading to alterations in essential amino acid production, which in turn is linked to autism. Dr. Seneff has produced a multitude of powerpoint presentations on this. One of the key pieces of evidence is a graph indicating a statistically airtight correlation between the increased rate of autism and an increase in glyphosate application in agriculture. That seems solid right?
Not so fast. While tantalizingly attractive, a graph does not indicate causation. One of the fundamental rules of toxicology is that toxicity is a function of dose. I haven’t seen any controlled dose-related studies she or fellow researchers have conducted that have been subjected to peer review. I guess I’d ask how do human gut bacteria react to the doses of glyphosate found in human food? And regarding the second part of the assertion, what amino acids, or lack thereof, correlate with an increased chance of autism? I’ve never heard what those are, nor have I ever, ever heard of an obstetrician, GP, or internist recommending additional doses to an expectant mother, tiny infant etc. So the entire claim is mystifying to me.
I think her conclusions are attractive to many for the same reason Dr. Wakefield’s were. Nobody wants a child with autism. But many parents bear the terrible burden of raising and caring for one. We want to find and stop “autism” whatever the source, because the burden is so unbearable. And those children and parents deserve and need our care and support.
There is no short cut to finding answers to hard questions. It is creativity, patience, hard work, and public debate. Pay attention to those whose work is reviewed and undramatically debated. That way, we may actually find a “cure” for autism.