The Human Brain May Contain as Much as a Spoons Worth of Microplastics, New Research SuggestsThe amount of microplastics in the human brain appears to be increasing over time: Concentrations rose by roughly 50 percent between 2016 and 2024, according to a new study Researchers found higher levels of microplastics in brain tissue than in liver and kidney tissue. UNM HealthThe human brain may contain up to a spoons worth of tiny plastic shardsnot a spoonful, but the same weight (about seven grams) as a plastic spoon, according to new findings published Monday in the journal Nature Medicine.Researchers detected these almost unbelievable levels of microplastics and nanoplastics in the brains of human cadavers, says study co-author Andrew West, a neuroscientist at Duke University, to ScienceNews Laura Sanders. In fact, I didnt believe it until I saw all the data.Based on their analysis, the amount of microplastics in the human brain appears to be increasing over time: Concentrations rose by roughly 50 percent between 2016 and 2024.The researchers also found much higher levels of microplastics in brain tissue than in liver and kidney tissue. And microplastic concentrations were also higher in the brains of deceased patients who had been diagnosed with dementia compared to the brains of deceased individuals without dementia.Importantly, the study finds only a correlation between high levels of microplastics in the brain and dementiait does not establish a causal relationship. It could be, for instance, that changes resulting from dementia make it easier for microplastics to accumulate in the brain. However, the researchers say their findings are troubling nonetheless.I have yet to encounter a single human being who says, Theres a bunch of plastic in my brain and Im totally cool with that, says study co-author Matthew Campen, a toxicologist at the University of New Mexico, in a statement.Microplastics and nanoplastics are miniscule plastic fragments that result from the breakdown of everyday objects like packaging, containers, clothing, tires and more. These small particles have spread all over the planet, from Mount Everest to deep in the Mariana Trench. Theyve also made their way into the human body, showing up in blood, baby poop, lungs and placentas.In September 2024, these miniature pollutants were also discovered in the human olfactory bulb, a type of brain tissue that sits above the nose in the forebrain. At the time, researchers werent completely sure whether microplastics could migrate deeper into the brain.The new paper suggests they can. First, researchers analyzed brain, kidney and liver tissue from patients who had died in 2016 and 2024. For broader context, they also studied brain tissue from patients who had died between 1997 and 2013. Some of the brains came from patients who had been diagnosed with dementia.They found much higher levels of microplastics in the 2024 brain tissue, on average, than in the 2016 brain tissue, regardless of the patients age, sex, race, ethnicity or cause of death. Their findings suggest microplastic levels in the brain have grown by roughly 50 percent over the last eight years. This increase makes sense in the context of plastic production, which doubles every 10 to 15 years, reports the Washington Posts Shannon Osaka.We think [the increase] is simply mirroring the environmental buildup and exposure, Campen tells National Geographics Olivia Ferrari. People are being exposed to ever-increasing levels of micro and nanoplastics.Microplastic levels were 7 to 30 times higher in the examined brain tissue than in the liver and kidney tissue.Microplastic concentrations were also three to five times higher in the brains of patients with dementia, compared to cognitively normal brains. Its not clear whether microplastics may cause or contribute to dementia, nor whether dementia-induced changes to the brain might allow more microplastics to enter.More broadly, the potential health consequences of microplastics remain largely unknown. Some recent research, however, suggests they are likely harmful to the human body. A study published in March 2024, for example, found that patients with higher concentrations of microplastics in their arteries were at a higher risk of heart attacks, stroke and death.Now that microplastics have been found deep in the human brain, the next steps will be to explore what effects, if any, they are having on human health.Future studies might also investigate how microplastics and nanoplastics are making their way into the brain in the first place, a feat that remains a mystery. Researchers are also curious about the unusual shapes of the plastic particles they found in the brain: thin, sharp shards, rather than the smooth, bead-like shapes they had expected.Somehow, these nanoplastics hijack their way through the body and get to the brain, crossing the blood-brain barrier, Campen tells CNNs Sandee LaMotte. Plastics love fats, or lipids, so one theory is that plastics are hijacking their way with the fats we eat, which are then delivered to the organs that really like lipidsthe brain is top among those.In the meantime, the world might want to consider mitigation measures to help minimize microplastic exposure, says Emma Kasteel, a neurotoxicologist at Utrecht University in the Netherlands who was not involved with the paper, to National Geographic.We dont know that much about the health effects, but the fact is that [microplastics] are [in the brain] and they shouldnt be there, and maybe thats worrying enough, she says.Get the latest stories in your inbox every weekday.Filed Under: Biology, Body, Brain, Environment, Health, Medicine, New Research, Plastic, Pollution