Microplastics May Promote Atherosclerosis in Male Arteries, UCR Study Finds

A recent mouse study led by the University of California, Riverside suggests that daily exposure to microplastics may accelerate atherosclerosis — but remarkably, the effect appeared only in male mice. UCR News+2ScienceDaily+2
Key Findings
- Male mice exposed to microplastics (10 mg/kg daily for 9 weeks) developed 63% more plaque in the aortic root and 624% more in the brachiocephalic artery. UCR News+1
- Female mice exposed to the same dose did not show significant plaque buildup. UCR News
- The increase in atherosclerosis was not driven by weight gain or high cholesterol, indicating microplastics may act through other mechanisms. Medical Xpress
- Using single-cell RNA sequencing, researchers found that microplastics disrupted endothelial cells (the cells lining blood vessels), triggering pro-atherogenic gene activity in both mouse and human endothelial cells. UCR News
- Fluorescent microplastic particles were observed inside arterial plaques, particularly in the endothelial layer — matching previous human studies that have detected microplastics in arterial lesions. Medical Xpress
- The sex-specific effect may be linked to hormonal or genetic differences (e.g., estrogen’s protective role), though the exact mechanism remains unknown. Environmental News Network+1
Why This Matters
- The study provides some of the strongest experimental evidence to date that microplastics might directly contribute to cardiovascular disease, not just appear in diseased tissues. UCR News
- The male-specific vulnerability may open new lines of investigation into sex-based protective factors against microplastic toxicity.
- Given how widespread microplastic exposure is — from food, water, and air — these findings raise serious concerns about long-term cardiovascular health risks.
- Prevention remains critical: it may be impossible to fully avoid microplastics, but reducing plastic use (especially single-use plastics) and managing cardiovascular risk factors is currently the most practical strategy. UCR News+1
How Ecotox Environmental Services Can Help
- Microplastic Exposure Monitoring
- Sample and quantify microplastic levels in water, air, and food sources relevant to human exposure.
- Vascular Risk Modeling
- Model how chronic microplastic exposure could increase atherosclerotic risk at population levels, considering sex-specific effects.
- Cellular Impact & Toxicogenomics
- Collaborate on or support in vitro / in vivo studies to examine how microplastics alter endothelial cell gene expression and function.
- Risk Assessment & Mitigation Strategy
- Develop risk-reduction strategies for microplastic exposure (e.g., policy advice, public education, plastic use guidelines) in vulnerable communities.

