Microplastics and Human Health: What We Know So Far
Article by Jude Ali A
Microplastics are small in size, yet raise increasingly big questions. These tiny plastic fragments, many too small to be seen without magnification, are now being detected in drinking water, seafood, indoor air, and even human tissues.
No longer confined to environmental headlines, they are increasingly becoming part of the broader conversation about human health. As research evolves, attention is shifting from where microplastics are found to what their presence in the body might mean for long-term health. Before exploring potential risks or practical steps, it helps to understand what microplastics actually are, how we are exposed to them, and what current science does and does not tell us.
What Are Microplastics?
Microplastics are tiny plastic particles, typically smaller than 5 millimeters, often invisible to the naked eye. They can be created intentionally, or form as larger plastics gradually break down in the environment.
An even smaller category, called nanoplastics, is now drawing scientific attention due to their potential to behave differently within the body.
Why Is This Being Studied More Closely?
The interest in microplastics goes beyond where they are found. It centres on how they may behave once inside the body.
Early laboratory research suggests that exposure to microplastics can trigger oxidative stress and inflammatory responses at a cellular level. Oxidative stress refers to an imbalance between free radicals and antioxidants in the body. A process that, when sustained over time, is associated with tissue damage.
Researchers are also investigating whether very small particles, particularly nanoplastics, may cross biological barriers more readily due to their size. Experimental data indicate that nanoplastics may penetrate intestinal and respiratory tissues, and in some cases enter circulation. Recent post-mortem analyses have even detected micro- and nanoplastic particles in human brain samples, prompting further research into how these particles might interact with sensitive tissues.
Another important consideration is the chemical composition of plastics themselves. Many contain additives such as bisphenols and phthalates, which are known endocrine-disrupting compounds. Microplastics may act as carriers for these substances, prompting further investigation into potential hormonal effects.
It is important to emphasise that much of this evidence comes from laboratory and animal studies. Long-term human data are still emerging, and clear conclusions about chronic disease risk have not yet been established. However, the biological responses observed so far are enough to justify continued research.
How Are We Exposed and What Happens Once They Enter?
Microplastics enter the body primarily through ingestion and inhalation, two exposure routes that are embedded in everyday life. These particles have been identified in everything from our favourite morning cup of tea and the warming honey we add to our porridge, to simple table salt and bottled water.
Beyond what we eat, microscopic plastic fibers also circulate in the air we breathe, often released from our synthetic gym wear, household dust, and the urban environment around us. Because of this, exposure isn't about making "wrong" choices; it is simply a reflection of the modern world we navigate daily.
At this point, you may be wondering: if microplastics are so widespread, can they realistically be avoided?
Eliminating exposure fully is not a realistic goal in the 21st century, but the focus of current science is firmly on understanding the behavior of these particles once they enter our system. While larger fragments are typically filtered or excreted by the body’s natural waste-management systems, nanoplastics present a different challenge. Due to their minute scale, they have the potential to interact with our primary biological defences, including the delicate linings of the lungs and the intestines.
Once these particles move beyond these barriers, they enter systemic circulation and are transported throughout the body.
What the Research Tells Us
While it can feel daunting to think of these particles within the body, detection is simply the
first step toward understanding. To date, microplastics have been identified in human blood, lung tissue, and placental samples. More recently, post-mortem analyses have detected micro- and nanoplastic particles in brain tissue, in some cases at higher concentrations than in other organs.
The detection of micro- and nanoplastics in brain tissue has understandably drawn attention and may feel quite startling. It’s natural to feel a bit shocked by that. You might be wondering, “If I’m eating or breathing it, how does it end up there?” The answer largely comes down to size. Larger fragments are typically filtered or excreted efficiently. Nanoplastics, however, are so small that they may behave differently. After crossing intestinal or respiratory barriers, they can enter circulation and travel throughout the body.
The brain is protected by a highly selective defence system known as the blood–brain barrier, a network of tightly joined cells designed to regulate what enters neural tissue. Emerging research suggests that particles at the nanoscale may be capable of interacting with this barrier in ways that are still being investigated.
The Science of Biological Resilience
Our bodies are remarkably adaptive and equipped with sophisticated detoxification and defence systems. The focus of current research is not alarm, but understanding, particularly how we can support resilience in the face of modern environmental exposures.
This brings us to an important concept in functional and integrative health: barrier integrity.
The gut lining acts as one of our primary interfaces with the external world. Supporting a healthy intestinal barrier through a nutrient-dense diet, fibre intake, microbial diversity, and anti-inflammatory foods may play a role in maintaining balance.
Practical ways to reduce your daily exposure
While we cannot change the global environment overnight, we can significantly reduce our personal "plastic load" by being intentional about the items that come into direct contact with our food and water.
Drawing on the latest research, here are several evidence-based steps to minimise the number of particles entering your system:
Filter Your Water: One of the most effective ways to reduce ingestion is to move away from bottled water, which often contains higher concentrations of microplastics. Using a high-quality water filter at home is a simple, proactive step.
The "Boil and Filter" Method: For those in hard-water areas, research suggests that boiling tap water can cause calcium carbonate (limescale) to "trap" microplastics. Once cooled, pouring the water through a simple coffee filter can remove a significant portion of these particles before you drink
Swap the Tea Bags: Many modern tea bags, particularly the "silky" pyramid types, are made from synthetic polymers that can release billions of microplastics into a single cup. Switching to loose-leaf tea with a stainless steel strainer is a beautiful, plastic-free alternative for your morning ritual.
Avoid Heating Plastic: Heat is a primary catalyst for the leaching of both chemicals and microplastics. Whenever possible, swap plastic storage containers for glass, ceramic, or stainless steel, particularly when reheating food in the microwave.
Dust and Ventilate: Since we also inhale microplastics from household dust (often shed from synthetic carpets and clothing), regular vacuuming with a HEPA filter and opening windows for fresh air can help clear the environment in your home.
The accumulation of microplastics is a measurable phenomenon of modern living, but it is not a cause for panic. It is a prompt for informed action. By focusing on what we can influence, our nutrition, water quality, and daily habits, we shift from passive concern to proactive health management. While research continues to evolve, supporting overall resilience remains a practical and empowering approach in the face of modern environmental exposures.
References
Anayamalik (2025) ‘Microplastic accumulation found in human brain tissue’, European Medical Journal. Available at: https://www.emjreviews.com/neurology/news/microplastic-accumulation-found-in-human-brain-tissue/ (Accessed: 8 February 2026).
Cleveland Clinic (2023) The blood-brain barrier: Out with the bad, in with the good. Available at: https://my.clevelandclinic.org/health/body/24931-blood-brain-barrier-bbb (Accessed: 8 February 2026).
Jahedi, F. and Jaafarzadeh Haghighi Fard, N. (2025) ‘Micro- and nanoplastic toxicity in humans: Exposure pathways, cellular effects, and mitigation strategies’, Toxicology Reports, 14, p.102043. doi:10.1016/j.toxrep.2025.102043.
Savchuk, K. (2025) ‘What’s the deal with microplastics, the material that “never goes away”?’, Stanford Medicine News Center. Available at: https://med.stanford.edu/news/insights/2025/01/ microplastics-in-body-polluted-tiny-plastic-fragments.html (Accessed: 8 February 2026).
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This blog post was written by Jude Ali A, a Clinical Nutrition and Health student at the University of Roehampton with a research focus in metabolomics.