— By Plasteurope.com correspondent — 

New research has cast doubts on claims concerning the scale of harm done to the human body due to the ingestion of microplastics and nanoplastics. A number of scientists have challenged the findings of earlier studies, which were said to have found high levels of micromaterials in human organs and tissue. Critics said the topic of microplastics in the body required more study, and that while the ingestion of microplastics took place, conclusive evidence of their levels in the body and long-term harm had yet to be established.

One such piece of critical research, Microplastics: State of the Evidence on Health Effects and Public Perception, published in Deutsches Ärzteblatt International (DIA), said, “Although it is now considered certain that humans are exposed to microplastics via food, products, and the environment, our knowledge of the possible health effects remains incomplete.

“No causal relationships have been proven to date between the uptake of microplastics and health effects. However, the available evidence suggests that, under certain conditions, microplastics may affect cellular signalling pathways, enzyme activity, and cell membrane properties.”

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The Guardian recently highlighted the criticism of one study, Bioaccumulation of Microplastics in Decedent Human Brains, published in 2024 in Nature magazine, which had claimed that high levels of microplastics in human brains could be rising, and rapidly. The study was challenged in the same publication last November, with one researcher critical of its findings, labelling it a “joke”.

Researchers told The Guardian that “the race to publish had led to rushed results and routine scientific checks sometimes being overlooked”.

The article published in DIA concluded by saying “the current state of knowledge suggests that the risk to consumers from microplastics is relatively low”, and that there was “a need for robust, validated analytical methods capable of reliably quantifying microplastics in biological matrices”.