1 What they are and how they reach our plates
Microplastics are plastic fragments smaller than 5mm. They can be intentionally produced (primary microplastics) or result from the degradation of larger plastic materials (secondary microplastics).
They make their way into food primarily in two ways:
- Through the food chain (fish, shellfish, crustaceans, but also salt and honey, to name just a few examples.)
- During processing and packaging (particularly in industrial foods and those stored in plastic containers).
2 Where they are most commonly found1
The foods most at risk include:
- Fish and seafood: These organisms filter the water and accumulate microplastics in their digestive tract.
- Sea salt: Salt is produced through the evaporation of seawater. During this process, everything present in the seawater – including plastic residue – remains trapped in the salt crystals.
- Drinking water (especially bottled water): Microplastics can enter bottled water during the bottling process or through the release of particles from the plastic itself (particularly when exposed to heat or light). Moreover, part of the contamination may originate from the initial water sources.
- Honey and sugar: These products can become contaminated during production, processing or packaging, due to exposure to environmental dust or the use of plastic tools. In industrial settings, microplastics can also settle from the surrounding air.
A recent study2 published in 2025 by Genomic Press, confirms the significant presence of microplastics in ultra-processed foods, with concentrations much higher than those found in whole foods.
3 Why it’s a problem
Ingested microplastics pose a risk3 because they can accumulate and affect the body at various levels:
- Gut microbiota4: Microplastics can alter its composition, reduce biodiversity and promote pro-inflammatory strains
- Gut-brain axis: An imbalance in the microbiota can also affect mood, anxiety and stress responses.
- Systemic inflammation: Accumulation may trigger a chronic inflammatory response
- Metabolism: It may contribute to metabolic disorders
- Endocrine and cardiovascular systems: The build-up of microplastics in the body has been linked to hormonal imbalances and processes associated with oxidative stress, factors that can impact overall health.organismo.
4 How we can protect ourselves
- Limit the consumption of highly processed foods or those packaged in plastic
- Opt for filtered water
- Store food in glass or steel containers
- Eat more fibre: This helps the body eliminate part of the ingested particles
Plastic has now become an invisible ingredient in our diet. But by making more conscious choices, we can reduce our exposure and promote a sustainable diet – for ourselves and for the environment.
