New Study Reveals Disturbing Effects of Microplastics on the Brain and Behavior of Mice
Scientists at the University of Rhode Island have uncovered alarming results in an experiment investigating the potential health impacts of microplastics. The study, conducted on mice, found that when old and young rodents drank water containing microscopic fragments of plastic over the course of three weeks, the pollutants accumulated in every organ of their bodies, including the brain.
Furthermore, the presence of microplastics was observed to cause behavioral changes similar to dementia in humans, as well as changes to immune markers in the liver and brain. The study’s neuroscientist, Jaime Ross, expressed her surprise at these findings, noting that even low doses of microplastics were sufficient to produce such effects within a short period of time.
While the results cannot be directly translated to humans, studies involving animal models play a vital role in clinical research. Indeed, recent studies have also found microplastics in the human intestine, bloodstream, lungs, and even the placenta. These findings have raised concerns among toxicologists, who stress the urgent need to understand the health implications of these pollutants, given that exposure has become virtually unavoidable.
In the experiments, mice of different ages were given water containing fluorescent polystyrene microplastics, while a control group was given normal drinking water. Their behavior was regularly assessed using open field and light-dark preference tests, both of which showed significant differences between the mice drinking microplastic-contaminated water and those in the control group. Notably, behavioral changes were more pronounced in older mice.
At the end of the three-week trial, researchers discovered red fluorescent particles of microplastics in every type of tissue they examined, including the brain, liver, kidney, gastrointestinal tract, heart, spleen, lungs, and even the feces and urine of the mice. This suggests that the microplastics are circulating throughout the body’s systems, including the central nervous system.
The presence of microplastics in the brain is particularly concerning, as it indicates that these potentially toxic pollutants are capable of crossing the immune barrier that separates the central nervous system from the rest of the bloodstream. This raises the possibility of neurocognitive issues.
The study’s findings are consistent with earlier research that found microplastics in the brains of mice just two hours after consuming a contaminated meal. Another study from 2022 demonstrated that ingested polystyrene microplastics can accumulate in the brains of mice, causing inflammation and impairing memory. However, this study did not identify any behavioral changes among the mice.
Despite some discrepancies between studies, Ross and her colleagues stress that it is now evident that polystyrene microplastics can travel to the brain and have detrimental effects after absorption. In their recent research, the team also discovered a decrease in the abundance of a protein called GFAP, which supports brain cells, following the ingestion of microplastics. Decreased levels of GFAP have been associated with early stages of neurodegenerative diseases and depression.
Ross plans to further investigate these concerning changes in future research. The study’s findings were published in the International Journal of Molecular Science.