Stars of New Year’s Eve seafood platters, accompanied by lemon, buttered bread and white wine. For many, oysters embody a healthy, raw diet and the taste of the sea. We imagine them coming from pure waters, far from big cities and their pollution…. and yet.
At Christmas, an exceptional dish… not completely spared
But this idyllic image is today damaged by science. A study published in December in the journal
Continental Shelf Research shows that even in rural areas little impacted by human activity, oysters can contain microplastics and microfibers. Modern pollution definitely no longer stops at the gates of ecosystems that we thought were preserved.
Researchers analyzed oysters farmed in a rural lagoon in Baja California, Mexico, as well as surrounding surface water, deep water, and sediment. This area is however renowned for its low human impact.
Invisible pollution even in the most remote lagoons
Result: microplastics and non-synthetic microfibers were found everywhere. The most frequently identified polymers were cellulose, cotton and polyester, resulting in particular from the degradation of clothing and plastic waste. These particles infiltrate the water, settle in the sediment and end up in the flesh of filter-feeding molluscs such as oysters.
This observation is consistent with other recent work. In 2024, concerning levels of glass fibers were detected in oysters and mussels farmed on the south coast of England. No marine ecosystem, even isolated, seems completely spared today.
Beyond the environment, the question becomes health. In March 2024 a study published in the New England Journal of Medicine indicated that people whose carotid artery tissue contained microplastics or nanoplastics had twice the risk of heart attack or stroke.
The right reflex in the kitchen to reduce exposure by 33%
Should we therefore remove oysters from the Christmas menu? Not necessarily. The good news is that the study also provides a simple and concrete solution.
Scientists have observed that microplastics are not evenly distributed throughout the oyster. A large part is concentrated in the interval liquid, in other words the famous “first water” which is found at the opening of the shell.
The action to adopt is therefore very simple: drain the water from the oysters before consuming them.
According to the study, this habit would reduce the ingestion of microplastics and microfibers by around 33%.
In practice:
- Avoid turning the oysters before opening so that they retain their water;
- Open them, then throw out the first water;
- Wait 15 to 30 minutes: the oyster disgorges naturally and produces new water, clearer and finer.
A little reflex in the kitchen, without impact on the taste pleasure, which allows you to continue to enjoy oysters while limiting your family’s exposure to these invisible pollutants.