Could Microplastics in the Ocean Affect Brain and Mobility Health?

Sarju Ganatra, M.D., FACC

Credit: American Heart Association

New research reveals a potential link between microplastic pollution in the ocean and the prevalence of cognitive, mobility, self-care and independent living disabilities among residents of coastal counties in the United States.

The data, which will be presented at the American Academy of Neurology’s 77th Annual Meeting, held on April 5 to 9, 2025, showed that areas with the highest levels of microplastics in ocean water had significantly higher rates of these disabilities than areas with the lowest levels.

While the study does not prove that microplastics directly cause disabilities, it highlights the need for further investigation into how environmental pollution might impact public health.

The cross-sectional study evaluated 218 coastal counties across 22 U.S. states to assess the prevalence of disabilities in areas with very high and low marine microplastic levels (MMLs). Micro- and nanoplastics (MNPs) are considered an emerging risk factor for cognitive decline, with recent research linking them to an increased prevalence of dementia.

Investigators sorted counties into four groups based on MMLs: low (zero to 0.005 microplastic pieces per cubic meter [pieces/m³]), medium (0.005 to 1 pieces/m³), high (1 to 10 pieces/m³) and very high (10 or more pieces/m³). They adjusted for factors that could impact the rate of disability, including depression, air pollution, stroke, heart disease, and wealth and resource distribution.

The mean prevalence of cognitive (memory and thinking) disability was 15.2% in counties with very high MMLs, compared with 13.9% in counties with low MMLs. Mobility disability was observed in 14.1% of individuals in high-MML areas, compared with 12.3% in low-MML areas. Self-care disability affected 4.2% of people in high-MML counties, whereas the prevalence was 3.6% in low-MML counties. Independent living disability was reported at 8.5% in high-MML areas, compared with 7.7% in low-MML areas.

Even after adjusting for confounders, areas with very high levels of microplastics in their water had a significantly higher prevalence of disability compared with counties with low MMLs.

In an interview with The Educated Patient, the study’s lead investigator, Sarju Ganatra, M.D., FACC, medical director of sustainability at Lahey Hospital & Medical Center, Burlington, Massachusetts, part of Beth Israel Lahey Health, discusses the surprising link between marine microplastic pollution and neurological disabilities and the urgent need for further research and policy action to mitigate exposure and protect public health.

Were you surprised by the strength of the association between microplastics and neurological disabilities?

Sarju Ganatra, M.D., FACC: Yes, the findings were striking. While we anticipated some level of correlation between marine microplastics and neurological disabilities, the strength of the association — especially after adjusting for multiple socioeconomic and health-related factors — was unexpected. Coastal counties with the highest microplastic exposure showed significantly increased rates of cognitive disabilities (18% higher), mobility disabilities (7% higher), self-care disabilities (9% higher) and independent living disabilities (9% higher) compared with those with the lowest exposure. The growing evidence of microplastics crossing the blood-brain barrier and triggering neuroinflammation underscores the urgency of this issue. These results highlight that microplastics may not just be an environmental issue but a public health crisis, particularly for vulnerable populations.

What steps can individuals take to minimize their exposure to microplastics in their daily lives?

SG: While systemic change is necessary, individuals can take steps to reduce their personal exposure to microplastics:

• Avoid plastic-packaged food and beverages: Choose glass, stainless steel or BPA-free alternatives.
• Reduce plastic use: Opt for reusable bags, containers and cutlery instead of single-use plastics.
• Be mindful of synthetic clothing: Wash clothes in a microfiber-catching laundry bag and air-dry when possible.
• Advocate for stronger regulations: Support policies limiting plastic production and improving waste management.

What further research is needed to better understand the health effects of microplastics?

SG: This study establishes a strong association but does not confirm causation.

To bridge this gap, we need the following:

• Longitudinal studies: Tracking individuals over time to establish direct causal links.
• Mechanistic studies: Understanding how microplastics cross the blood-brain barrier and affect neurological function.
• Microbiome research: Investigating how gut microbiota changes due to microplastic exposure influence brain health.
• Clinical studies: Measuring microplastic levels in human tissues and correlating with disease progression.
• Policy impact assessments: Evaluating how environmental policies can mitigate exposure and subsequent health effects.

What’s the biggest takeaway you hope patients and the public get from your study?

SG: Microplastic pollution is not just an ocean or wildlife issue; it’s a human health issue. The significant link between marine microplastics and neurological disabilities suggests that environmental pollutants may be silently contributing to rising cognitive decline, mobility impairments and loss of independence. This study underscores the urgent need for action, both at a policy level to reduce plastic waste and at a personal level to minimize exposure.

While this research focuses on coastal counties due to measurable exposure levels, plastic pollution is a global issue impacting everyone, not just those living near the ocean. Microplastics permeate our entire ecosystem, affecting air, water and food sources worldwide. To protect both human and environmental health, we must take meaningful steps to reduce plastic use in daily life — such as avoiding plastic-bottled beverages and excessive plastic packaging. Our health is deeply connected to planetary health, and it is our responsibility to safeguard it — not just for ourselves, but for future generations.