Study finds common herbicide could be causing Alzheimer’s

A commonly used herbicide could be causing neurodegenerative illnesses, like Alzheimer’s, by crossing the blood-brain barrier, according to scientists.

Glyphosate is the most common herbicide in the world and is regarded generally safe to humans by the Environmental Protection Agency and European Food Safety Authority.

Researchers from the Translational Geonomics Research Institute (TGen) studied how exposure to the herbicide would affect mice brains and discovered it could cross the blood-brain barrier.

They also found it could enhance levels of a critical molecule TNF-α which performs vital functions in the neuroimmune system, boosting immune response and protecting the brain.

When levels of the molecule are dysregulated it can cause neuroinflammation and related diseases to crop up, including Alzheimer’s.

‘We find increases in TNF-α in the brain, following glyphosate exposure,’ said senior author of the study Roman Velazquez. ‘While we examined Alzheimer’s Disease pathology, this might have implications for many neurodegenerative diseases, given that neuroinflammation is seen in a variety of brain disorders.’

It was also found that glyphosate exposure led to a build-up of a sticky protein Aβ, a diagnostic hallmark of Alzheimer’s, and disruptions in the expression of genes related to neurodegenerative disease.

As of 2020, an estimated 5.8 million American’s lie with the disease, according to the Centers for Disease Research, and costs for treating the disease is expected to rise to $500bn annually by 2040.

Researchers are studying how environmental and other factors decrease or increase the likelihood of developing the illness, as 14 million people are expected to develop Alzheimer’s by 2050.

Each year, 250 million pounds of glyphosate is applied to crops in the US alone, but few studies have focused on the possible long-term effects of prolonged exposure.

The team of scientists who worked on the study say potential brain health risks of glyphosate should be evaluated to protect those consistently exposed to the herbicide.

‘The Alzheimer’s connection is that there’s a much higher prevalence of Alzheimer’s disease in agricultural communities that are using this chemical,’ said Joanna Winstone, first author of the study. ‘We’re trying to establish a more molecular-science based link between the two.’

More research is needed before a causative link can be established, while new drugs which can reduce TNF-α in the brain are being developed.

Photo by Scott Goodwill