Microplastics are everywhere, from the highest mountains to the deepest seas and even in rainwater, as recently detected in Jakarta, Indonesia. Now, for the first time, scientists have confirmed the presence of microplastics in human gastric tissues and believe they could be a risk factor for the development and progression of gastric cancer.
Despite a general decline in prevalence over the last few decades, cases of gastric cancer remain high, particularly in East Asia. With poor prognosis and survival rates, gastric cancer is the third leading cause of cancer deaths worldwide, and research is urgently needed to understand the risk factors for its development and progression.
“In tumor tissues, the enrichment level of microplastics is significantly higher than that in para-tumor and normal tissues, indicating that tumor cells may endocytose more microplastics than normal cells, causing oxidative stress and a series of inflammatory reactions in cells, leading to cell malignant transformation and tumorigenesis,” explains Anqiang Wang, researcher at Peking University Cancer Hospital and Institute and lead author of the study published in Advanced Healthcare Materials.
“In addition,” he continues, “extracellular matrix degradation and other metastasis-related signalling pathways were significantly enriched in tumor tissues with higher microplastic load, which may create potential conditions for tumor cell metastasis.”
Pervasive plastic
By 2015, almost 5 billion metric tons of plastic had accumulated in landfills and the environment, polluting marine and terrestrial ecosystems. These plastics degrade into smaller fragments, and those between 1 and 5mm in diameter are known as microplastics.
In addition to their environmental impact, microplastics pose a significant risk to human health. Owing to their small size, microplastics can infiltrate soil, plants, and marine environments and enter the food chain where animals and humans ingest them. The excessive use of plastic in the food industry further adds to the risk of ingestion. Plastics have been detected in human blood, tissues, lungs, and faeces as well as bone and skeletal muscle.
A groundbreaking study published in 2024 linked the amount of microplastics in carotid artery plaque to a higher risk of heart attack, stroke or death. Recent research published in 2025 not only documented bioaccumulation of microplastics in the brains of people who had died, but also detected greater amounts in those who had dementia. Adding to the concern for human health is research suggesting microplastics are hotspots for antimicrobial resistance – one of the biggest health challenges we face today.
Microplastics enter the stomach through ingestion and inhalation, where immune cells recognise these particles as foreign and try break them down. This results in inflammation and cell damage. Such pathological processes may cause malignancy, but there is little known about the risk of cancer associated with long-term exposure.
Microplastics may catalyse gene alterations that kickstart gastric cancers
The pioneering work of Wang and colleagues is the first to characterize microplastics in both normal and cancerous human gastric tissue and to investigate the genetic changes associated with this.
The researchers collected tissue from 24 patients undergoing surgery for gastric cancer. They sampled three types of gastric tissue: healthy, tumor, and tissue adjacent to the tumor, known as para-tumor. Characterizing and quantifying microplastics, the team detected microplastics in all three tissue types, with tumors containing significantly higher concentrations compared to normal tissue or para-tumors.
Studying the transcriptome or the RNA of the cell enabled the team to investigate genetic changes related to microplastics. Firstly, gastric tissue with a higher amount of microplastics had an upregulation of the genes associated with poor prognosis. Conversely, there was downregulation of genes associated with important cellular functions such as organization of the extracellular matrix that structurally supports cells in tissue.
“This suggests that the presence of [microplastics] may disrupt the tumor microenvironment, potentially affecting tumor progression and the behavior of surrounding tissues,” noted the researchers in their study.
But how are these genetic changes initiated?
One way appears to be through single-nucleotide polymorphisms (SNPs), a type of mutation where one DNA base pair is changed. The team’s finding that higher amounts of microplastics in gastric tumors induce more SNPs suggests microplastics may be the catalyst for gene alterations that kickstart and progress gastric cancer.
Microplastics may lead to cancer-driving gene fusions
In addition to SNPs, the researchers discovered the presence of gene fusions (a type of DNA rearrangement that can drive cancer) but only in gastric tissue with high microplastics load.
“Such gene fusions, including those related to FRY [a gene that has an important role during cell division], may affect cellular processes such as cell division, contributing to gastric cancer progression and potentially offering new insights into therapeutic targets for treatment,”explained the researchers in their paper.
Furthermore, microplastics may promote the spreading of cancer with study findings relating high microplastics load to lymph node metastasis- the most common metastasis pathway in gastric cancer.
“These findings suggest that we should pay enough attention to the health risks caused by microplastics in daily life, such as reducing the use of plastic products in takeaway food; especially under high temperature conditions, hot food may further release microplastics in plastic containers and dissolve into food, leading to potential health risks.”
Where’s the proof? Challenges in microplastics and human health research
So far, most of the evidence for the detrimental effects of microplastics on human health stem from findings of association between microplastics and changes to cells or biological processes. While these imply a link, they do not prove causation. In vitro human cell line studies and pre-clinical models enable investigation into the effects of microplastics on biological processes, but in vivo human studies are rare.
While this study suggests a high microplastic load is a risk factor for the development and progression of gastric cancer, larger prospective studies conducted over a prolonged period need to confirm this. Even then, it will be difficult to conclusively prove, because microplastics are omnipresent, meaning you cannot compare a group of unexposed people with an exposed group, because everyone is exposed.
Further hampered by a lack of standardisation in the identification and quantification of microplastics, progressing this crucial research poses a real challenge, but Wang and colleagues are up for the challenge.
“Our next research direction is to further expand the sample size of the study and confirm the association between microplastics exposure and gastric cancer risk from an epidemiological point of view,” noted Wang. This won’t be straightforward, as he explains: “The challenge in doing so is to rule out confounding in large cohort studies, the presence of bias, and differences in results due to various treatment and nontreatment factors. In addition, sample collection for multi-centre large cohort study is a difficult task, especially for healthy people.”
This research adds to the mounting evidence for the widespread presence of microplastics in our bodies. Questions remain about how exactly microplastics alter cells and biological processes andmore experimental evidenceand studies are needed to answer this.
What is clear is that research in this field is growing rapidly and is of relevance to us all. Reducing consumption of plastic is vital, if not for the good of the environment and planet then at least for the good of our own health.
References:
L. Chen et al., Characterization of Microplastics in Human Gastric Cancer and Control Tissues and Analysis of Associated Genetic Features, Advanced Healthcare Materials (2025), DOI: 10.1002/adhm.202504291
H. C. Wilyalodia, S. S. Moersidik, M. A. Pratama, Microplastic Contamination in Urban Groundwater: A Case Study From Jakarta Megacity, Indonesia, The Scientific World Journal (2024), DOI: 10.1155/tswj/1870706
P. Lalrinfela et al., Microplastics: Their effects on the environment, human health, and plant ecosystems, Environmental Pollution and Management (2024), DOI: 10.1016/j.epm.2024.11.004
A. J. Nihart et al., Bioaccumulation of microplastics in decedent human brains, Nature Medicine (2025), DOI: 10.1038/s41591-024-03453-1
R. Marfella et al., Microplastics and Nanoplastics in Atheromas and Cardiovascular Events, New England Journal of Medicine (2024), DOI: 10.1056/NEJMoa2309822
K. A. Hussain et al., Assessing the Release of Microplastics and Nanoplastics from Plastic Containers and Reusable Food Pouches: Implications for Human Health, Environmental Science & Technology (2023), DOI: 10.1021/acs.est.3c01942
S. Lu et al., New insights: Discovery of microplastics in human bone and skeletal muscle, The Innovation Medicine (2024), DOI: 10.59717/j.xinn-med.2024.100100
Featured image: “Microplastics on Hand” by Ark. Agricultural Experiment Station via Flickr, CC BY 2.0
