A new study out of Japan suggests people who are exposed to glyphosate – the active ingredient in Monsanto Roundup – may be more likely to develop Parkinson’s disease.
Epidemiological research has already suggested that exposure to glyphosate may influence the development of Parkinson’s disease in humans. For this study, researchers at Chiba University in Japan administered “drinking water” to four groups of adult mice laced with either:
The animals’ brains were evaluated after 14 days of daily administration.
According to the authors, exposure to glyphosate appeared both to worsen the ability of local neurons to produce and transport dopamine effectively, and to intensify the neurotoxicity of other extrinsic chemicals (in this case, MPTP). They concluded that exposure to glyphosate may be an environmental risk factor for Parkinson’s disease and could increase the risk of the disorder later in life.
Glyphosate remains the most popular weed killer in the world, despite being linked to a range of other adverse health effects, including liver disease, birth defects and reproductive problems in laboratory animals. Research also suggests glyphosate may kill beneficial gut bacteria and damage the DNA in human embryonic, placental and umbilical cord cells.
In March 2015, the World Health Organization’s International Agency for Research on Cancer declared glyphosate a probable human carcinogen, after an independent review linked occupational exposure to an increased risk of cancer, especially non-Hodgkin’s lymphoma and its various subtypes.
In February 2019, a study conducted by University of Washington researchers suggested glyphosate exposure increased the risk of non-Hodgkin’s lymphoma by as much as 41%. That same year, the U.S. Centers for Disease Control’s Agency for Toxic Substances and Disease Registry said it couldn’t rule out a cancer link and called for further investigation.
Bayer AG, which acquired Monsanto last year, is currently defending more than 52,000 Monsanto Roundup lawsuits that blame glyphosate for causing various forms of non-Hodgkin’s lymphoma. So far, all three juries convened to hear these cases have conclude the herbicide was a substantial factor in the plaintiffs’ cancer. Even after trial judges reduced the juries’ verdicts, the combined judgments totaled more than $191 million.
Bayer is currently participating in court-ordered mediation aimed at resolving the massive Roundup litigation. Earlier this year, reports indicated the parties were close to agreeing on a settlement in the range of $10 billion. However, talks have slowed in recent weeks due to the global coronavirus pandemic.