What neuroscience reveals about plastic exposure, ageing, and memory
npnHub Editorial Member: Dr. Justin James Kennedy curated this blog
Key Points
- Scientists are investigating whether exposure to microplastics and plastic-associated chemicals may contribute to cognitive difficulties in older adults, particularly as environmental exposures become an increasingly important area of public health research.
- Observational studies have identified associations between certain plastic-associated chemicals, including bisphenol A (BPA) and phthalates, and poorer performance on some cognitive and memory assessments.
- A study involving 961 older Americans reported an association between a particular category of BPA exposure and poorer immediate memory and overall cognitive performance among women, although the findings do not establish causation.
- Researchers have detected microplastics and nanoplastics in human brain tissue, including samples from individuals with dementia, but these findings do not demonstrate that plastic particles cause memory loss or neurodegenerative disease.
- Potential biological mechanisms under investigation include oxidative stress, neuroinflammation, endocrine disruption, and interference with cellular processes that contribute to healthy neural communication.
- Neuroscience practitioners can help clients understand emerging environmental research while supporting established approaches to cognitive health, including physical activity, adequate sleep, meaningful learning, and appropriate medical assessment.
1. What Is the Connection Between Plastic Exposure and Memory in Older Women?
Imagine a neuroscience practitioner working with a 67-year-old woman who has recently become concerned about changes in her memory. Although she continues to manage her daily responsibilities, she has noticed that recalling unfamiliar names takes longer than it once did, and she occasionally forgets appointments unless she writes them down. These experiences have made her increasingly attentive to information about cognitive ageing and the factors that might influence brain health.
During a wellbeing consultation, she mentions an article suggesting that exposure to plastics may affect the ageing brain. She wonders whether ordinary household products, including the food containers she has used for years, could be contributing to the changes she has noticed.
This is an illustrative example, not a scientific case.
The client’s concern reflects an emerging area of environmental neuroscience in which researchers are investigating whether exposure to plastic particles and chemicals associated with certain plastics may influence cognitive function.
However, it is important to distinguish between the different substances being studied. Microplastics are small plastic particles, while nanoplastics are even smaller particles that may interact with biological systems differently. Bisphenols and phthalates, by contrast, are chemicals used in certain plastics and other consumer products. Although they are associated with plastic manufacturing and use, they are not themselves microplastic particles.
This distinction matters because evidence concerning the health effects of a particular chemical cannot automatically be applied to microplastic particles. The substances differ in their properties, exposure pathways, and potential biological effects.
In 2023, researcher Yisen Shi and colleagues published an observational study examining the relationship between environmental chemical exposure and cognitive performance among older Americans. The researchers identified an association between one intermediate category of BPA exposure and poorer immediate recall and overall cognitive performance among female participants (Shi et al., 2023).
Although these findings raise important questions about environmental influences on cognitive ageing, they do not demonstrate that BPA exposure caused memory decline.
For neuroscience practitioners, the significance lies in recognizing environmental exposure as one possible area of investigation while maintaining a broader understanding of the many factors that influence memory in later life.
2. The Neuroscience of Plastic Exposure and Memory
Imagine a wellbeing educator introducing a group of neuroscience practitioners to the biological systems involved in memory. She begins by describing the hippocampus, a brain structure essential for forming new memories and organizing information about experiences. She then explains how memory depends on communication between multiple brain regions, supported by healthy cellular processes and carefully regulated chemical signaling.
As the discussion develops, the educator raises an important question: what might happen if certain environmental substances interfere with the biological conditions required for effective neural communication?
This is an illustrative example, not a scientific reference.
Learning and memory depend on coordinated activity across several interconnected brain regions. The hippocampus plays a central role in forming and organizing new memories, while the prefrontal cortex contributes to attention, working memory, decision-making, and the strategies used to retrieve information. The entorhinal cortex provides an important connection between hippocampal and cortical memory systems, while regions of the temporal cortex contribute to the representation and retrieval of knowledge.
For these networks to function effectively, neurons must communicate through tightly regulated chemical and electrical processes. Neurotransmitters such as glutamate and GABA contribute to excitatory and inhibitory signaling, while acetylcholine plays an important role in attention and memory-related processes.
Researchers are investigating several mechanisms through which environmental plastic-associated exposures might influence these systems.
One possibility involves oxidative stress, which occurs when the production of reactive molecules exceeds the body’s ability to manage them through normal protective mechanisms. Excessive oxidative stress can interfere with cellular function and may contribute to tissue damage.
Another area of investigation is neuroinflammation, involving inflammatory responses within the nervous system. Although inflammation is part of normal biological defense and repair, persistent or dysregulated inflammatory activity may interfere with healthy neuronal function.
Endocrine disruption represents a third potential mechanism. Certain bisphenols and phthalates can interfere with hormone-related signaling, raising questions about possible effects on biological processes relevant to brain function, particularly across different stages of life.
A 2025 review published in Nature Medicine examined the growing evidence concerning microplastic and nanoplastic exposure and their possible implications for human health. Lamoree and colleagues emphasized that important uncertainties remain, including how exposure should be measured and whether findings from experimental systems can be translated into reliable predictions of human health outcomes (Lamoree et al., 2025).
Animal and cellular studies can provide valuable insights into possible biological mechanisms, but their findings cannot automatically be assumed to occur at the same magnitude in people experiencing ordinary environmental exposure.
The brain regions of particular interest include the hippocampus, prefrontal cortex, entorhinal cortex, temporal cortex, and the wider networks involved in memory, attention, and executive function.
What remains uncertain is whether everyday exposure to plastic particles or associated chemicals produces clinically meaningful damage in these human brain networks.
3. What Neuroscience Practitioners, Neuroplasticians and Well-being Professionals Should Know About Plastic Exposure and Memory
Imagine a neuroscience coach working with a woman in her seventies who has become increasingly worried about her memory. After reading several articles about microplastics, the client has started replacing household products, avoiding particular foods, and examining everyday items for possible sources of contamination. She is convinced that environmental exposure must explain her recent forgetfulness.
As the practitioner explores her circumstances, however, a broader picture begins to emerge. The client has been experiencing disrupted sleep, considerable stress, and several changes in her medication routine. These factors may also influence cognitive performance, suggesting that concentrating exclusively on microplastics could lead to other important concerns being overlooked.
This is an illustrative example, not a scientific case.
Professionals working with older adults should understand that memory changes can arise from multiple interacting causes. Normal ageing may influence the speed with which certain information is processed or retrieved, while sleep disruption, mood difficulties, medication effects, cardiovascular conditions, and neurological disorders can also affect cognitive functioning.
Environmental plastic exposure is an emerging research topic, but it is not an established explanation for the memory symptoms of an individual client.
In their 2023 study, Shi and colleagues examined 961 older Americans, including 491 women. The researchers reported an association between one category of BPA exposure and poorer immediate recall and overall cognitive performance among female participants.
However, their findings were not uniformly stronger among women. Some of the more consistent associations involving BPA exposure and delayed recall were observed among male participants (Shi et al., 2023).
This complexity is also reflected in subsequent research.
In a 2025 study, Huidi Du and colleagues investigated relationships between mixed exposure to phenols, parabens, phthalates, and cognitive performance among older Americans. Their findings suggested stronger associations between certain chemical exposure mixtures and poorer cognitive outcomes among men rather than women (Du et al., 2025).
These differences illustrate why sex-specific findings should be interpreted carefully. Results from one observational study may not be reproduced in another population, and differences in exposure measurements, study design, or participant characteristics can influence the associations observed.
Professionals frequently encounter questions such as:
- Does higher plastic exposure directly cause memory loss in older women?
- Are older women more vulnerable than men to the potential cognitive effects of plastic-associated chemicals?
- Can reducing plastic exposure improve memory or protect against dementia?
At present, the available evidence does not provide definitive answers to these questions.
Observational associations are scientifically meaningful because they help researchers identify possible relationships that warrant further investigation. However, they do not establish causation, determine the precise biological mechanisms involved, or demonstrate that reducing exposure will reverse cognitive symptoms.
For neuroscience practitioners, the most responsible approach is to communicate the findings without unnecessary alarm, while helping clients consider the wider biological, psychological, and lifestyle factors that contribute to cognitive health.
4. How Plastic Exposure May Affect Neuroplasticity
Neuroplasticity allows the nervous system to adapt through experience, learning, and changes in neural activity. These adaptations depend on communication between neurons, the regulation of synaptic connections, and the cellular processes that support the formation, stabilization, and retrieval of memories.
For memory to function effectively, the brain must maintain coordinated activity across multiple networks. Synaptic plasticity helps modify the effectiveness of communication between neurons, allowing neural circuits to respond to repeated experiences and changing demands.
These processes rely on healthy cellular functioning, adequate energy metabolism, balanced neurotransmitter signaling, and appropriate regulation of inflammatory responses.
Researchers are investigating whether environmental plastic particles or associated chemicals could interfere with some of these biological conditions.
For example, excessive oxidative stress may affect cellular structures and processes involved in neuronal communication, while inflammatory signaling may influence the environment in which neurons function. Endocrine-disrupting chemicals could also interact with hormone-sensitive processes relevant to brain health.
These possibilities are biologically plausible, but they should not be confused with direct evidence that ordinary plastic exposure reduces neuroplasticity in humans.
In 2025, Alexander Nihart and colleagues published a study reporting the detection of microplastics and nanoplastics in human brain tissue. Their research also identified higher measured concentrations in a small group of deceased individuals with documented dementia (Nihart et al., 2025).
The findings attracted considerable attention because they suggested that plastic particles may accumulate in tissues previously thought to be relatively protected from certain environmental substances.
However, the researchers did not establish that plastic accumulation caused dementia.
An important alternative explanation is that changes associated with neurological disease, such as altered blood-brain barrier function or impaired tissue clearance, might influence how particles accumulate in the brain. The direction of any relationship between plastic accumulation and neurodegenerative processes therefore remains uncertain.
The study also did not identify a significant relationship between measured brain particle concentrations and sex, making it inappropriate to conclude that women necessarily accumulate more microplastics in brain tissue than men.
For neuroscience practitioners, the relationship between plastic exposure and neuroplasticity remains an important research question rather than a settled scientific conclusion.
It is possible that certain environmental exposures influence biological processes involved in neural adaptation, but direct evidence demonstrating that everyday plastic exposure impairs learning-related neuroplasticity in humans is still insufficient.
Maintaining this distinction is essential. It helps protect clients from unnecessary fear while preventing exaggerated claims about detoxification, memory restoration, or the reversal of neurological disease through changes in plastic consumption alone.
5. Neuroscience-Backed Interventions to Support Brain Health and Reduce Unnecessary Exposure
Behavioral interventions matter because emerging environmental health concerns can create considerable anxiety, particularly when scientific findings are presented without sufficient context. A neuroscience practitioner may work with an older woman who wants to protect her memory but feels overwhelmed by conflicting information about plastics, household products, and possible neurological risks. The central challenge is helping clients respond thoughtfully to developing evidence without assuming that every plastic product causes harm or that reducing exposure will reverse cognitive decline. The following strategies combine reasonable environmental precautions with interventions supported by stronger evidence for cognitive health. None has been demonstrated to remove microplastics from the brain, reverse dementia, or restore memory through plastic reduction alone.
1. The Plastic Exposure Awareness Audit
Concept: Researchers are increasingly investigating how microplastics and nanoplastics enter the human body through environmental pathways, including food, water, and inhalation. Understanding these exposure routes is important, although substantial uncertainty remains about the amount of exposure associated with specific health outcomes.
Lamoree and colleagues reviewed emerging evidence on microplastic and nanoplastic exposure, highlighting the need for better measurement methods, long-term human studies, and more reliable assessments of potential health effects (Lamoree et al., 2025).
Example: A neuroscience practitioner works with a client who is concerned about the amount of plastic used in her household. After reading several alarming articles, the client is considering replacing almost every plastic item she owns.
Rather than encouraging an expensive or unnecessarily restrictive response, the practitioner helps her identify areas where reducing disposable plastic use may be practical, affordable, and consistent with her environmental preferences.
Intervention:
- Ask the client to identify the disposable plastic products she uses most frequently.
- Explore reusable alternatives where they are practical, accessible, and affordable.
- Encourage the use of food-contact containers according to manufacturer instructions.
- Explain that different plastic products vary in composition, intended use, and potential exposure pathways.
- Review these changes as informed environmental choices rather than proven treatments for memory loss.
The purpose is to support thoughtful decision-making without creating the impression that eliminating every plastic item is necessary for cognitive health.
2. Reduce Unnecessary Contact With Plastic-Associated Chemicals
Concept: Observational studies have identified associations between exposure to certain plastic-associated chemicals and cognitive performance in older populations. These findings raise questions about possible long-term effects but do not establish that reducing exposure improves memory.
Weng and colleagues investigated phthalate exposure and cognitive performance among 835 older American adults. Their findings identified associations between some phthalate exposure measures and poorer performance on immediate or delayed recall tasks (Weng et al., 2022).
Example: A wellbeing professional supports a client who regularly stores and reheats meals in plastic containers. The client is interested in reducing unnecessary contact with plastic-associated chemicals but does not want to replace all her kitchen equipment or introduce complicated food preparation routines.
The practitioner helps her identify a few manageable changes while explaining that the research does not demonstrate that these adjustments will improve cognitive performance.
Intervention:
- Review whether food containers are intended for the temperatures and uses involved.
- Consider glass or stainless steel alternatives for selected storage and food preparation tasks.
- Avoid using damaged containers or products unsuitable for food contact.
- Prioritize practical changes that do not create unnecessary financial pressure.
- Explain that reducing exposure is a precautionary choice, not an established treatment for memory decline.
The goal is to support reasonable exposure management while maintaining an accurate understanding of the scientific evidence.
3. Support Memory Through Regular Physical Activity
Concept: Compared with the emerging evidence concerning plastic exposure, regular physical activity has a more established research foundation for supporting brain health and selected aspects of cognitive performance.
In a randomized controlled trial involving older adults, Erickson and colleagues demonstrated that one year of aerobic exercise training increased anterior hippocampal volume and improved spatial memory. Their findings suggest that sustained physical activity can influence brain structures involved in memory (Erickson et al., 2011).
Example: A neuroscience coach works with a 68-year-old woman who has become concerned about age-related changes in memory. Although she has been researching environmental exposures, she has become less physically active since retiring.
The practitioner encourages her to consider how regular movement could become part of a broader approach to maintaining cognitive health, rather than focusing exclusively on possible environmental contaminants.
Intervention:
- Begin with a comfortable amount of physical activity appropriate to the client’s current abilities.
- Gradually work toward regular movement based on health status and individual needs.
- Incorporate enjoyable activities that encourage long-term consistency.
- Monitor changes in energy, wellbeing, mobility, and everyday functioning.
- Adapt the routine with appropriate medical guidance when necessary.
Regular exercise does not guarantee protection against dementia, but it remains an important component of healthy ageing and can support several aspects of physical and cognitive wellbeing.
4. Strengthen Memory Through Active Learning
Concept: Memory performance can benefit from learning strategies that encourage active retrieval rather than repeated passive exposure to information. When a person attempts to recall previously learned material, they engage processes that can strengthen long-term retention.
Karpicke and Roediger demonstrated that repeated retrieval practice improved delayed retention compared with additional studying under specific experimental conditions (Karpicke & Roediger, 2008).
Example: An educator works with an older woman who enjoys reading books, attending community lectures, and learning about unfamiliar subjects. Although she remains intellectually curious, she often struggles to remember the details of what she has recently read.
The educator introduces short retrieval exercises, encouraging her to recall information before reviewing it again. The aim is to make learning more active while supporting confidence in her ability to acquire and retain new knowledge.
Intervention:
- Encourage the client to choose a subject or skill that is personally meaningful.
- After reading or practicing, ask her to recall the main ideas without referring to notes.
- Review forgotten information and repeat retrieval at a later time.
- Include opportunities for social learning when they are enjoyable and accessible.
- Track progress in the specific knowledge or skill being practiced rather than assuming broad improvements in memory.
The objective is to support meaningful cognitive engagement through established learning principles, without presenting cognitive exercises as guaranteed protection against neurodegenerative disease.
5. The Memory Concern Assessment Practice
Concept: Some changes in memory can occur during normal ageing, but persistent or worsening cognitive difficulties may indicate medical, psychological, or neurological conditions that require assessment.
The US National Institute on Aging explains that memory problems can arise from multiple causes, including medication effects, mood disorders, sleep difficulties, treatable medical conditions, and neurological disease.
National Institute on Aging: Memory, Forgetfulness, and Aging
Example: A wellbeing practitioner works with a client whose memory concerns are beginning to interfere with everyday activities. The client has missed important appointments, become confused about routine financial tasks, and noticed that family members are increasingly concerned about her ability to manage familiar responsibilities.
Although the client wonders whether environmental plastic exposure might be contributing to these difficulties, the practitioner recognizes that identifying a medical explanation is more urgent than attempting to manage the symptoms through environmental changes alone.
Intervention:
- Ask the client to describe specific changes in memory and everyday functioning.
- Encourage documentation of when the difficulties began and whether they are becoming more frequent.
- Suggest discussing medications, sleep, mood, and relevant health conditions with an appropriate healthcare professional.
- Encourage timely medical or cognitive assessment when symptoms persist or worsen.
- Avoid attributing memory difficulties to plastic exposure without clinical evidence.
The most valuable intervention may be identifying a treatable cause of cognitive symptoms or ensuring that the client receives appropriate specialist support.
6. Key Takeaways
Plastic exposure and cognitive ageing have become increasingly important areas of environmental neuroscience as researchers investigate whether microplastics, nanoplastics, and plastic-associated chemicals influence brain health.
Observational studies have identified associations between certain chemical exposures and cognitive performance, including some findings involving older women. Scientists have also detected plastic particles in human brain tissue, raising questions about possible biological effects and their relevance to neurological disease.
However, these discoveries do not establish that plastic exposure causes dementia or that reducing exposure restores memory. For neuroscience practitioners, the most responsible approach combines informed environmental awareness with established strategies for supporting cognitive health.
- Distinguish exposure types: Microplastic particles and plastic-associated chemicals are not interchangeable.
- Interpret associations carefully: Some studies link BPA and phthalate exposure with poorer cognitive performance, but causation has not been established.
- Avoid unsupported sex-specific conclusions: Evidence that older women are uniquely vulnerable remains inconsistent.
- Understand the limits of brain tissue findings: Detecting microplastics in the brain does not demonstrate that they cause dementia.
- Encourage practical environmental choices: Reasonable exposure precautions may be considered without exaggerated health claims.
- Prioritize established cognitive health practices: Physical activity, meaningful learning, adequate sleep, and appropriate medical assessment remain important.
The most useful response to emerging scientific evidence is neither unnecessary fear nor premature dismissal. It is a thoughtful approach that recognizes uncertainty while supporting informed decisions about health and wellbeing.
7. References
- Du, H., Wang, Q., Chen, Y., Wu, X., Jiang, J., & Zhao, Y. (2025). Association between mixed exposure of phenols, parabens, phthalates and cognitive function in US elders. Journal of Affective Disorders, 382, 139–147. https://doi.org/10.1016/j.jad.2025.04.079
- Erickson, K. I., Voss, M. W., Prakash, R. S., et al. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences, 108(7), 3017–3022. https://doi.org/10.1073/pnas.1015950108
- Karpicke, J. D., & Roediger, H. L., III. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968. https://doi.org/10.1126/science.1152408
- Lamoree, M. H., van Boxel, J., Nardella, F., et al. (2025). Health impacts of microplastic and nanoplastic exposure. Nature Medicine, 31, 2873–2887. https://doi.org/10.1038/s41591-025-03902-5
- Nihart, A. J., Garcia, M. A., El Hayek, E., et al. (2025). Bioaccumulation of microplastics in decedent human brains. Nature Medicine, 31, 1114–1119. https://doi.org/10.1038/s41591-024-03453-1
- Shi, Y., Wang, H., Zhu, Z., Ye, Q., Lin, F., & Cai, G. (2023). Association between exposure to phenols and parabens and cognitive function in older adults in the United States: A cross-sectional study. Science of the Total Environment, 858, 160129. https://doi.org/10.1016/j.scitotenv.2022.160129
- Weng, X., Tan, Y., Fei, Q., et al. (2022). Association between mixed exposure of phthalates and cognitive function among the U.S. elderly from NHANES 2011–2014: Three statistical models. Science of the Total Environment, 828, 154362. https://doi.org/10.1016/j.scitotenv.2022.154362
8. Useful Links
- PubMed: Plastic-Associated Chemicals and Cognitive Function in Older Adults
- PubMed: Mixed Phthalate Exposure and Cognitive Performance in Older Americans
- PubMed: Mixed Phenol, Paraben, and Phthalate Exposure and Cognition
- Nature Medicine: Bioaccumulation of Microplastics in Human Brain Tissue
- Nature Medicine: Health Impacts of Microplastic and Nanoplastic Exposure
- US Food and Drug Administration: Microplastics and Nanoplastics in Foods
- European Food Safety Authority: Microplastics and Nanoplastics in Food
- National Institute on Aging: Memory Problems, Forgetfulness, and Aging
- PubMed Central: Exercise Training and Hippocampal Volume
