Source: The amount of tiny plastic particles is increasing in the environment and also in the human body. “Microplastics are omnipresent in the food we eat, the water we drink and the air we breathe,” write three researchers in the journal Brain Medicine in a commentary on several previous studies.

They point out possible dangers – but above all how the intake of such particles can be reduced: by avoiding plastic bottles, ceramic dishes for the microwave and plastic-free tea bags, for example.

Another team recently found significantly more tiny plastic particles in liver and brain samples from people who died in 2024 than in those from 2016. The concentration was much higher in the brain than in the liver or kidneys, the group led by Matthew Campen from the University of New Mexico reported in February in the journal Nature Medicine.

The drastic increase in plastic concentration in the brain within just eight years is extremely worrying, said the lead author of the commentary, Nicholas Fabiano from the University of Ottawa.

Tiny plastic particles in the brain

Particularly small particles were discovered in the brain, measuring less than 0.2 micrometers. They consisted mainly of polyethylene, which is found in numerous everyday objects. Due to their small size, they can overcome the so-called blood-brain barrier. The effects are still unclear. Microplastics are particles between 1 micrometer (0.001 millimeters) and 5 millimeters. Nanoplastic particles are even smaller.

Plastic particles in water and through certain tea bags

Everyone can reduce their intake of nano- and microplastics themselves, explains the research trio. If a person covers their water needs only from plastic bottles, for example, they can absorb more than 20 times as many particles as someone who only uses tap water, the researchers write, referring to an earlier study.

Water from glass bottles also contains more plastic particles than tap water, as researchers write in an analysis of 21 studies. This could be caused by bottling processes, among other things.

Another source of micro- and nanoplastics are plastic tea bags. Leaving a plastic tea bag to brew at 95 degrees can release significant amounts of it, the research trio’s commentary says. It is therefore better to avoid such tea bags.

Plastic containers for food release particles

In addition, avoiding plastic containers for food can be effective. “Heating food in plastic containers – especially in the microwave – can release large amounts of micro- and nanoplastics,” warned fellow commentator Brandon Luu from the University of Toronto. Even long-term storage at room temperature or in the refrigerator leads to a significant release of particles, according to the researchers.

“Using glass or stainless steel containers instead of plastic is a small but significant measure to minimize exposure,” Luu said.

Chemicals in canned food

Canned food can contain substances that come from plastics, such as bisphenol-A (BPA). In one study, subjects were given canned soup for five days in a row, after which their BPA levels in urine increased several times over. The researchers also emphasize: “However, the duration of these BPA peaks and their health effects are unclear and require further research.”

Another US study has shown that highly processed foods contain significantly more microplastics than minimally processed foods.

The trio sees at least one positive finding: “One of the most hopeful aspects of the results so far is the lack of a correlation between age and microplastic accumulation.” This suggests “that despite ongoing environmental influences, the body has mechanisms to excrete these particles over time through sweat, urine and feces.”

Possible consequences for the body

There are indications from cell culture and animal experiments that the plastic particles could promote inflammation, immune disorders, altered metabolism, abnormal organ development and cancer, among other things, write the commentators. However, the study situation is poor so far. Large-scale studies with humans are needed to determine the potential health risk of microplastics. In parallel, studies should better evaluate the effectiveness of various reduction strategies.

There are only a few studies on the effects of microplastics in the brain. Campen’s team discovered an increased concentration in twelve other brain samples from people with proven dementia. Campen’s group emphasizes, however, that the study does not prove a direct cause-and-effect relationship.

They note, it is also conceivable that dementia weakens the blood-brain barrier and therefore more microplastics can penetrate.

Photo Old Fadama, Central African Republic by Rebecca Bliklen on Unsplash.