A recent study discovered that human brain samples from individuals who were cognitively normal and had passed away in early 2024 contained more minuscule plastic fragments compared to samples collected eight years earlier. Lead study author Matthew Campen, a Regents’ Professor and professor of pharmaceutical sciences at the University of New Mexico, revealed that brain samples had significantly higher levels of plastic shards, ranging from seven to 30 times more than in the kidneys and liver. The average concentration found in the brain tissue of individuals around 45 to 50 years old was 4,800 micrograms per gram, equivalent to 0.48% by weight, similar to an entire standard plastic spoon.
Campen noted that this increase in plastic levels represents a 50% rise compared to brain samples from 2016, suggesting that current brains are nearly 99.5% brain and the remainder is plastic. While acknowledging the potential for measurement methods to either underestimate or overestimate plastic levels in the body, Campen emphasized ongoing efforts towards a precise estimation within the next year.
In a concerning discovery, researchers identified three to five times more plastic fragments in the brains of individuals diagnosed with dementia before death, compared to healthy brains. These microscopic plastic shards, primarily located in the brain’s vascular walls and immune cells, raised alarm due to their association with impaired blood-brain barrier function and clearance mechanisms in dementia.
Campen urged caution in interpreting the results, highlighting the need for further research to determine the impact of microplastics on neurological health. Notably, the presence of plastic deposits in the brain does not necessarily imply direct harm, as stated by Phoebe Stapleton, an associate professor at Rutgers University, who emphasized the importance of investigating the potential toxicological consequences and cellular interactions of these particles.
The study also observed indications that the body’s liver and kidneys might possess the ability to eliminate some plastics, although the brain’s capacity for plastic clearance remains uncertain. Pediatrician and biology professor Dr. Philip Landrigan underscored the significance of the increasing prevalence of microplastics in human tissues, correlating this trend with the surge in plastic production, pollution, and human exposure over recent years. Landrigan’s research with the Minderoo – Monaco Commission on Plastics and Human Health highlights the urgency of understanding the implications of heightened plastic exposure on public health.
In the 2023 report, a consortium of workers and policy analysts dedicated to tracking plastics from production to final product revealed that plastics are linked to health risks at every stage of their lifecycle. According to Landrigan, studies have detected these harmful plastics in various parts of the human body, including the heart, blood vessels, lungs, liver, testes, gastrointestinal tract, and placenta. The presence of these microplastic particles poses a significant concern as they can transport numerous toxic chemicals found in plastics, some of which are known to have detrimental effects on health.
Nanoplastics have the potential to infiltrate cells and tissues in vital organs, disrupting cellular processes and releasing endocrine-disrupting chemicals such as bisphenols, phthalates, flame retardants, heavy metals, and per- and polyfluorinated substances (PFAS). These endocrine disruptors can interfere with the reproductive system, leading to reproductive malformations, infertility, and decreased sperm count, as noted by the Endocrine Society. While the full extent of harm caused by microplastics and nanoplastics is still being studied, Landrigan emphasized the need for precautionary measures based on existing evidence.
While the American Chemistry Council has stated that current scientific evidence does not indicate a direct health risk from microplastics or nanoplastics in food, ongoing research aims to address gaps in understanding exposure and toxicity. The complexity of microplastics, variations in assessment methods, and potential impacts on human health underscore the importance of developing reliable tools for evaluating their effects.
Recent research has uncovered tiny plastic particles in various human tissues, including the placenta, breast milk, testes, liver, kidneys, carotid arteries, and even the brain. A study published in the journal Nature Medicine found evidence of nanoplastics entering brain tissues, kidneys, and liver from individuals who underwent autopsies. This highlights the potential risks associated with microplastic contamination and the urgent need for further investigation into its impact on human health.
“Small nanostructures, ranging from 100 to 200 nanometers in length, are approximately the size of two COVID viruses placed next to each other,” shared Campen, who also serves as the head of the New Mexico Center for Metals in Biology and Medicine. Nanoplastics are considered the most concerning plastics for human health due to their ability to infiltrate individual cells. “These nanoplastics somehow navigate their way through the body and reach the brain by crossing the blood-brain barrier,” Campen explained. “Plastics have an affinity for fats, or lipids, leading to a theory that they may be hitching a ride with the fats we consume, which are then transported to lipid-rich organs, with the brain being a primary target.”
The human brain, consisting of about 60% fat by weight, requires essential fatty acids like omega-3s for optimal function and resilience. Since the body cannot produce these essential fatty acids independently, they must be obtained from food or supplements. Landrigan emphasized that diet is the primary route of exposure to micro- and nanoplastics, though some particles can also be airborne, particularly from tire abrasion on highways and wave action in coastal regions.
To reduce exposure to plastics and minimize plastic waste, individuals can take several practical steps. Landrigan urged individuals not to panic, acknowledging that complete avoidance of plastics is impractical in the modern world. Instead, he advised minimizing exposure to avoidable plastics, especially single-use items. Suggestions included unwrapping foods from plastic packaging before heating them to prevent microplastics from leaching into the food, using fabric bags instead of plastic at the dry cleaner, bringing reusable mugs and silverware to reduce plastic cup and utensil usage, and choosing glass or metal containers for food storage over plastic ones. Landrigan also recommended supporting community efforts to ban plastic bags and emphasized the importance of individual actions in collectively reducing plastic pollution.
“He suggested collaborating with other advocates for children’s health to advocate for restrictions on plastic manufacturing and the use of safer chemicals in plastics. He emphasized that just because we may not have full knowledge about every chemical in plastics, it doesn’t deter us from addressing the harmful chemicals we are already aware of.
Editor’s Note: This article was initially composed in August 2024 using a preprint, an early version of a paper that had not undergone peer review. It has been revised to mirror the final peer-reviewed and published version in Nature.
For additional CNN news and newsletters, please sign up for an account at CNN.com.”
