Many AutismOne speakers promote the idea that the introduction of genetically engineered food in the mid-1990s and the use of glyphosate (RoundUp) are the cause of autism. This argument stems almost entirely from the claims of Stephanie Seneff, a computer scientist. The crux of Seneff’s claims is that the increase in autism rates correlate in time with an increase in cultivation of transgenic crops (the accurate term for GMOs), thus GMOs and a corresponding increase in glyphosate use must cause autism. The tongue in cheek response to this is to compare the rise in autism diagnoses with the rise in organic food sales or to point people to this website that identifies all sorts of unrelated things that happen to have a high correlation.
They also suggest that removing GMOs from the diet will reverse autism. This claim is nonsense based on what we know about the genetics and neuroscience of autism.
There are many claims about the health effects and GMOs. Here, we focus specifically on the supposed link between GMOs and autism and provide science- and evidence-based articles about this question.
Let’s start with a reminder that while the diagnosis of autism, the broad consensus among scientists is that this is due to changing diagnostic criteria and that the prevalence has not actually changed (discussed here and here). This entire hypothesis that GMOs or glyphosate are responsible for an increase in autism is predicated on the fact that there is an actual increase in autism. Again, data suggests that there has not been a real increase in the prevalence of autism, but rather an increase in awareness and diagnosis.
There are two major problems with Seneff’s central claim that half of all children will be autistic by 2025. First, it assumes the increase in diagnosis reflects an increase in prevalence (it doesn’t as discussed above). Second, it assumes that this increase in diagnosis will continue at the same rate indefinitely (CDC data suggests we may have reached a plateau, but we need data from subsequent years to make that statement with confidence). Seneff’s assumptions in this premise of her are not based on data, they are just poor assumptions.
Seneff’s claim is not backed by evidence because there is none. It also fails the plausibility test.
BLOGS AND ARTICLES
Two thorough discussions of everything that is wrong with Seneff’s argument.
Additional articles based on scientific evidence:
Roundup and Gut Bacteria discusses the claim that glyphosate leads to autism by affecting gut bacteria.
Rough calculations of how much glyphosate would need to be ingested to reach a dose in the human stomach to inhibit the shikimate pathway in the bacteria (the pathway glyphosate targets, which people don’t have) in your stomach have been done here.
Snopes tackled this issue in this article, Glyphosatan:
Whether educated or not, guesswork is only the start of research in epidemiology, and no published research exists to prove (or even suggest) a link between glyphosate and autism. No evidence was presented in the article to provide context for why glyphosate (or GMOs) would be any more likely to account for the presumed increase than other environmental factors, and it appeared the only visible connection between the two was their inclusion on a graph presented at a conference of an indeterminate nature.
A review of developmental effects of glyphosate exposure:
Williams AL, Watson RE, DeSesso JM. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis.2012;15(1):39-96.
A review of studies of glyphosate exposure and non-cancer outcomes (non-cancer respiratory conditions, diabetes, myocardial infarction, reproductive and developmental outcomes, rheumatoid arthritis, thyroid disease, and Parkinson’s disease):
Mink PJ, Mandel JS, Lundin JI, Sceurman BK.Epidemiologic studies of glyphosate and non-cancer health outcomes: a review. 2011Nov;61(2):172-84.
Information on glyphosate toxicity from the National Pesticide Information Center