Infinity Group Medical Director Dr Krish Rawal, investigates the possible effects of microplastics on our health and environment.

For this week’s article I wanted to look at something which we all hear about and know about but perhaps do not entirely understand how health can be affected, and that is the subject of microplastics. There is of course a lot of misinformation that makes the truth difficult to interpret.

Microplastics are defined as plastic particles smaller than 5 mm, but even smaller nanoplastics have become ubiquitous environmental contaminants, entering the human body through food, drinking water, inhalation, and, potentially medical products. Researchers have detected these particles in human blood, lungs, placenta, liver, kidneys and brain, prompting growing concern about their potential health effects. However, while their presence is now well established, the clinical significance remains an area of active investigation. A recent Nature Medicine review concluded that evidence linking microplastic exposure to adverse health outcomes is accumulating, but important uncertainties remain regarding how much exposure can cause harm, and the biological mechanisms involved. A 2026 Nature Reviews Gastroenterology & Hepatology commentary emphasised the need for standardised methods to distinguish genuine biological effects from contamination effects, showing how there is quite a lot of uncertainty where microplastics are concerned.

Experimental studies suggest several plausible mechanisms through which microplastics may affect health. These include chronic inflammation, oxidative stress, disruption of the gut microbiome, impairment of the intestinal barrier, endocrine disruption, and transport of potentially harmful chemicals adhered to the plastic surface. Observational studies have also reported associations between microplastic accumulation and cardiovascular disease, chronic kidney disease, and neurological disorders, although these findings do not establish causation. Importantly, many of the current data come from laboratory or animal studies, and translating these findings to real-world human exposure remains difficult. A comprehensive review in Nature Reviews Nephrology highlighted that although microplastics have been identified in multiple human tissues, the long-term health consequences require further investigation before firm clinical conclusions can be drawn.

For clinicians, the key message is one of cautious interpretation rather than alarm. As Nature recently observed, “more rigorous science is needed” to determine which reported findings are reliable and what they mean for human health. Similarly, experts writing in Nature Reviews Gastroenterology & Hepatology stress the importance of rigorous study design, standardised reporting, and careful interpretation before causal links can be established. While it is reasonable to encourage measures that reduce unnecessary plastic pollution and exposure, the current evidence does not support attributing specific diseases directly to microplastics in individual patients. Over the coming decade, advances in exposure assessment and long-term epidemiological studies are likely to clarify whether microplastics represent a major modifiable risk factor or primarily an environmental marker of modern living.

So despite my best intentions, I do not think I have managed to clear up the confusion that much, but it does make for interesting reading! However surely exposure to micro plastics cannot be good irrespective of what the evidence currently says.