Surg Neurol Int. 2015; 6: 45.

Published online 2015 Mar 24. doi:  10.4103/2152-7806.153876

PMCID: PMC4392553

Glyphosate, pathways to modern diseases III: Manganese, neurological diseases, and associated pathologies

Anthony Samsel and Stephanie Seneff1,*

Manganese (Mn) is an often overlooked but important nutrient, required in small amounts for multiple essential functions in the body. A recent study on cows fed genetically modified Roundup®-Ready feed revealed a severe depletion of serum Mn. Glyphosate, the active ingredient in Roundup®, has also been shown to severely deplete Mn levels in plants. Here, we investigate the impact of Mn on physiology, and its association with gut dysbiosis as well as neuropathologies such as autism, Alzheimer's disease (AD), depression, anxiety syndrome, Parkinson's disease (PD), and prion diseases.

Glutamate overexpression in the brain in association with autism, AD, and other neurological diseases can be explained by Mn deficiency.

Mn superoxide dismutase protects mitochondria from oxidative damage, and mitochondrial dysfunction is a key feature of autism and Alzheimer’s.

Chondroitin sulfate synthesis depends on Mn, and its deficiency leads to osteoporosis and osteomalacia.

Lactobacillus, depleted in autism, depend critically on Mn for antioxidant protection. Lactobacillus probiotics can treat anxiety, which is a comorbidity of autism and chronic fatigue syndrome. Reduced gut Lactobacillus leads to overgrowth of the pathogen, Salmonella, which is resistant to glyphosate toxicity, and Mn plays a role here as well.

Sperm motility depends on Mn, and this may partially explain increased rates of infertility and birth defects.

We further reason that, under conditions of adequate Mn in the diet, glyphosate, through its disruption of bile acid homeostasis, ironically promotes toxic accumulation of Mn in the brainstem, leading to conditions such as PD and prion diseases.

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It may seem implausible that glyphosate could be toxic to humans, given the fact that government regulators appear nonchalant about steadily increasing residue limits, and that the levels in food and water are rarely monitored by government agencies, presumably due to lack of concern.

However, a paper by Antoniou et al. provided a scathing indictment of the European regulatory process regarding glyphosate's toxicity, focusing on potential teratogenic effects. They identified several key factors leading to a tendency to overlook potential toxic effects. These include using animal studies that are too short or have too few animals to achieve statistical significance, disregarding in vitro studies or studies with exposures that are higher than what is expected to be realistically present in food, and discarding studies that examine the effects of glyphosate formulations rather than pure glyphosate, even though formulations are a more realistic model of the natural setting and are often orders of magnitude more toxic than the active ingredient in pesticides.

Regulators also seemed unaware that chemicals that act as endocrine disruptors (such as glyphosate) often have an inverted dose–response relationship, wherein very low doses can have more acute effects than higher doses.

Teratogenic effects have been demonstrated in human cell lines. An in vitro study showed that glyphosate in parts per trillion can induce human breast cancer cell proliferation.

Keywords: Autism, cholestasis, glyphosate, manganese, Parkinson's disease