In a groundbreaking preliminary study unveiled at the American Heart Association’s Vascular Discovery 2025 Scientific Sessions, researchers have uncovered a startling correlation between the presence of micronanoplastics—microscopic plastic particles—and the development of plaque in the carotid arteries of the neck. These arteries, critical conduits delivering oxygen-rich blood to the brain, are vulnerable to narrowing caused by the buildup of fatty deposits known as plaque. This new research suggests that these deposits harbor concentrations of micronanoplastics at levels dramatically higher than those found in healthy arteries, with implications that may redefine our understanding of stroke risk factors.
Micronanoplastics, a term encompassing a mixture of micro- and nanoscale plastic particles, are generated both industrially and through the environmental degradation of larger plastic debris. Distinguished by their diminutive scale—microplastics measuring under 5 millimeters, often visible to the naked eye, and nanoplastics being almost unimaginably smaller at less than 1,000 nanometers—these particles have distinct pathways into the human body. Their small size facilitates penetration into tissue and cellular structures, raising concerns about their biological interactions and potential toxicity.
The research team, led by Dr. Ross Clark, a vascular surgeon-scientist at the University of New Mexico, conducted an analysis on 48 carotid artery samples collected from adults ranging in age from 60 to 90. The cohort was divided equally among individuals with symptomatic carotid artery disease—those who had experienced stroke, mini-stroke, or transient visual impairment—patients with asymptomatic plaque buildup, and healthy tissue donors without arterial plaque. Utilizing pyrolysis gas chromatography-mass spectrometry, a sophisticated analytical method, the researchers quantified the plastic content within these samples.
Remarkably, they observed that carotid plaques from asymptomatic patients contained 16 times the amount of micronanoplastics compared to healthy arteries, with concentrations escalating dramatically—51 times higher—in plaques from symptomatic individuals. These findings introduce a provocative link between the microscopic pollution burden within vascular tissue and the manifestation of clinical events such as stroke or transient ischemic attacks. Endlessly circulating in polluted air, water, and food sources, micronanoplastics have until now escaped scrutiny as potential contributors to cardiovascular disease.
Given their minute size, nanoplastics are especially insidious; they evade conventional filtration, infiltrate cells, and potentially disrupt molecular pathways. Experimental evidence from this study hints at complex biological effects extending beyond acute inflammation. Genetic analyses revealed altered activity patterns in the cells responsible for maintaining plaque stability—specifically in macrophages and stem cells—with indications of suppressed anti-inflammatory gene expression in macrophages residing within high-plastic-content plaques. This nuanced molecular portrait suggests that micronanoplastics may subtly undermine vascular health through immunological mechanisms that remain to be fully elucidated.
While the technique employed to detect micronanoplastics in biological tissue represents a technical breakthrough, it is not without challenges. Pyrolysis gas chromatography-mass spectrometry breaks down plastic polymers into smaller molecules for identification, but biological tissues harbor similar compounds that can complicate signals. Lipids, abundant in fatty plaques, share spectral characteristics with polyethylene, one of the most common plastics. The research team is actively refining sample preparation methods to reduce lipid interference and enhance measurement accuracy, underscoring the ongoing evolution of analytical technologies in this emerging field.
Importantly, the researchers emphasize that these early findings are correlative and not yet evidence of causation. The presence of micronanoplastics may be a marker of other pathological processes rather than a direct driver of vascular disease. Additional longitudinal studies with larger populations and mechanistic laboratory investigations are essential to decisively map the role these particles play in arterial plaque formation, progression, and symptom manifestation.
This research raises urgent public health considerations. Unlike traditional modifiable risk factors for stroke—such as hypertension, smoking, and cholesterol levels—exposure to micronanoplastics is ubiquitous and currently unavoidable due to their proliferation in the environment. Dr. Clark cautions that existing methods to mitigate human exposure are ineffective, as these particles pervade water, soil, and food supplies globally. Future strategies to combat cardiovascular disease risk may need to integrate environmental toxin reduction alongside classical lifestyle interventions.
The findings also spotlight a previously overlooked dimension of the plastic pollution crisis. Environmental plastic waste is often discussed in terms of ecological harm, but as this study suggests, human health impacts may be equally profound, operating through insidious, cellular-level mechanisms. The accumulation of micronanoplastics in blood vessel walls exemplifies a new frontier at the interface of environmental science and cardiology, demanding interdisciplinary research approaches.
Further bolstering these concerns, earlier work in Italy demonstrated that individuals with carotid plaques containing micronanoplastics faced worse clinical outcomes over several years, including higher mortality and increased incidence of nonfatal cardiovascular events. Together, these studies amplify the urgency of understanding how environmental contaminants seep into human tissues and influence disease processes.
The American Heart Association’s expert reviewers, while praising the innovative nature of this research, highlight its preliminary status and the need for caution when interpreting these findings. Dr. Karen L. Furie, vice chair of the Stroke Brain Health Science Subcommittee and an eminent neurologist, stresses the novelty of considering micronanoplastic exposure as a modifiable risk factor for stroke. She calls for robust mechanistic studies to clarify the pathways through which these plastic particles might contribute to carotid atherosclerosis.
Social awareness of microparticles’ health implications is also evolving. This study underscores the importance of revisiting consumer habits and public policies around plastic use, environmental protection, and contamination control. In an era where plastic materials dominate human environments, deciphering their hidden effects on human physiology is paramount.
In closing, this provocative research heralds a paradigm shift in cardiovascular disease science, suggesting that minuscule plastic pollutants may integrate into vascular biology in ways previously unimagined. As the environmental and biomedical sciences converge, new avenues are opening to explore how ubiquitous anthropogenic materials disrupt human health and how society can respond. The journey from environmental exposure to vascular pathology illuminated by these findings will undoubtedly stimulate extensive inquiry in the years ahead.
Subject of Research: Micronanoplastics accumulation in carotid artery plaques and its association with stroke and related symptoms.
Article Title: Micronanoplastic Pollution Inside Neck Arteries: Unveiling a Hidden Risk Factor for Stroke
News Publication Date: April 22, 2025
Web References:
American Heart Association Vascular Discovery 2025 Scientific Sessions: https://professional.heart.org/en/meetings/vascular-discovery-from-genes-to-medicine
Stroke Information: https://www.stroke.org/en/about-stroke
Carotid Artery Plaque Details: https://www.heart.org/en/health-topics/cholesterol/about-cholesterol/atherosclerosis
Keywords: micronanoplastics, carotid artery plaque, stroke risk, vascular biology, microplastics, nanoplastics, atherosclerosis, vascular inflammation, macrophage gene activity, environmental health, plastic pollution, cardiovascular disease
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