A groundbreaking study from the University of California, Riverside has unveiled a troubling link between everyday microplastic exposure and accelerated artery disease, with men facing a disproportionate threat. Published on November 17, 2025, in Environment International, the research reveals how these invisible invaders—shed from packaging, clothing, and consumer plastics—can supercharge plaque buildup in arteries, potentially fast-tracking heart attacks and strokes. Strikingly, the damage appeared exclusively in male mice, hinting at sex-specific vulnerabilities that demand urgent attention in human health.
Microplastics, those minuscule particles smaller than five millimeters, have infiltrated nearly every corner of modern life. Found in bottled water, seafood, indoor dust, and even human blood and lungs, they stem from the breakdown of larger plastics or direct shedding during manufacturing. While prior human observations detected these fragments in atherosclerotic plaques—the fatty deposits that harden arteries—scientists lacked proof of causation. This new work bridges that gap, demonstrating direct harm at environmentally realistic doses.
Led by biomedical scientist Changcheng Zhou, the team used LDLR-deficient mice, a gold-standard model for studying heart disease due to their genetic predisposition to high cholesterol and plaque formation. For nine weeks, male and female mice received daily oral doses of 10 milligrams per kilogram of polystyrene microplastics—equivalent to what humans might ingest through contaminated food and water—while on a lean, low-fat diet. This setup isolated microplastics’ effects from traditional risk factors like obesity or high cholesterol.
The results were alarming, but sex-specific. Female mice showed no significant changes, their arteries remaining largely unscathed. Males, however, suffered dramatic escalation: plaque volume surged 63% in the aortic root, the heart’s direct arterial gateway, and skyrocketed 624% in the brachiocephalic artery, a key upper-chest vessel. Fluorescently tagged microplastics confirmed the particles’ presence inside plaques and along the intimal layer—the thin endothelial cells lining blood vessels—mirroring discoveries in human carotid artery samples.
Delving deeper with single-cell RNA sequencing, researchers uncovered chaos at the cellular level, again limited to males. Endothelial cells, crucial for regulating blood flow and inflammation, exhibited widespread dysfunction. Harmful genes tied to plaque formation and immune overdrive fired up, while protective pathways faltered. “Microplastics are disrupting the vascular firewall,” Zhou explained, likening the effect to poking holes in a dam. This endothelial betrayal allows lipids and immune cells to infiltrate artery walls, fueling atherosclerosis.
Why the male bias? Hormonal differences, such as testosterone’s role in inflammation, or sex chromosomes’ influence on immune responses, emerge as prime suspects. The study echoes broader patterns where environmental toxins hit men harder in cardiovascular contexts. Future probes will dissect these mechanisms, testing varied microplastic types, sizes, and long-term exposures.
This isn’t abstract science—it’s a wake-up call amid escalating plastic pollution. Global production hit 400 million tons annually in 2024, with projections climbing, and human microplastic loads doubling every decade. Cardiovascular disease already claims 18 million lives yearly, the top global killer. If mouse findings translate, microplastics could explain rising early-onset heart issues in younger men, independent of diet or smoking.
No quick fix exists to purge microplastics from the body, but prevention starts at home. Opt for glass or stainless steel over plastic packaging, filter tap water, and choose natural-fiber clothing to curb shedding. Broader action—stricter manufacturing regs, beach cleanups, and biodegradable alternatives—gains momentum, with the UN’s plastic treaty talks accelerating post-COP30.
Zhou’s team urges sex-tailored screenings and research, emphasizing that “as pollution rises, so does the urgency to protect hearts.” For men, this means doubling down on basics: balanced diets, regular exercise, and cholesterol checks. In a world awash in synthetics, this study spotlights an overlooked enemy, urging us to rethink what we ingest, inhale, and ignore. The arteries we save may be our own.