How harmful are microplastics in your body to your health?

Microplastics have by now been detected literally everywhere in the human body: in blood, urine, faeces, lung tissue, breast milk, semen and the placenta. Exposure occurs through eating, drinking and inhaling. That they are present is established fact. Whether and how seriously they cause harm is considerably less certain.

In cell and animal research the picture is worrying. Microplastics can trigger inflammation, oxidative stress (a kind of rusting process in cells) and DNA damage. The immune system cannot clear plastic particles efficiently, which can give rise to low-grade, persistent inflammation. How much damage this produces at the quantities people typically take in is not yet known.

Three specific areas deserve particular attention. First, the gut: microplastics accumulate in the gastrointestinal tract and disrupt the bacterial balance, which in animal research was linked to intestinal inflammation. Second, the lungs: inhaled particles have been associated with reduced lung function and chronic lung inflammation, but human data are scarce. Third, male fertility: animal research suggests that sperm quality declines with exposure. Some human observational data exist, but they are still too limited for firm conclusions.

The most alarming questions -- such as cancer risk, effects on unborn children and neurological complaints -- are purely hypothetical at this point. There are theoretical mechanisms, but no solid human studies demonstrating a causal link. That is not a reassuring conclusion; it indicates rather that research in this area has not yet progressed far enough to provide reliable answers.

If you want to limit your exposure, the most practical steps are: eat and drink less from plastic packaging (and certainly never heat food in plastic), prefer tap water or filtered water over bottled water, and minimise the spread of synthetic textile fibres in the home via the dryer or washing machine.