Whether it's a rogue chicken breast or the last of a lasagna, many of us regularly pop our leftovers in the freezer. But it turns out you've probably been doing it wrong this entire time. While plastic containers are the go-to for many Brits, experts now say that these should be avoided. Instead, the team at Which? say that you should freeze leftovers in glass or steel containers.
Plastic Containers and Microplastics
'Freezer-safe glass and steel containers provide a durable and long-lasting alternative to plastic for freezing leftovers,' the consumer champion explained. 'When frozen, plastic can become brittle. This can cause tiny fragments to break off and release as microplastics. Heating products in plastic containers also increases the release of microplastics which can leach directly into the food itself.'
Before you ditch all your plastic tupperware, the consumer champion reassures that these containers are fine for everyday storage and chilling. 'If you're preparing food for the freezer or the microwave it's useful to have alternatives on hand,' it explained.
What Are Microplastics?
Microplastics are tiny plastic fragments that measure less than 5mm across. Whether it's a plastic bag, a tupperware, or a bottle, they tend to come from larger products, which shed them as they break down into smaller pieces. If you use plastic containers to freeze or reheat food, this could be problematic. 'Repeatedly heating or freezing plastics (such as storage containers) can exacerbate this breakdown,' Which? explained. 'That makes food preparation and storage a particular source of exposure to microplastics.'
Environmental and Health Concerns
Studies have already uncovered strong evidence that microplastics cause harm to the environment. For example, research has revealed that microplastics can interfere with the ability of small organisms and plants to store carbon. In turn, this disrupts the blue carbon cycle – the carbon stored by marine life – which is critical in mitigating climate change.
However, scientists still don't know their long-term impact on human health, although they've now been found in human blood, lungs, placenta, and even breast milk. 'The blood brain barrier (BBB) is the thin shield around the brain that protects against threats like bacteria, toxins and chemicals,' the UK Health Security Agency (UKHSA) explained in a recent blog. 'At the same time, the barrier allows oxygen and nutrients to pass through tiny holes guarded by specialist cells.
Nanoplastics are so incredibly small that they can slip past these defensive cells, known as pericytes, or hitch a ride on nutrients making their way to the brain. These pericyte cells primarily help to maintain the barrier and clear toxins that threaten the brain.'
Worryingly, several neurodegenerative diseases are linked with these cells. The UKHSA added: 'Diseases such as Alzheimer's and Parkinson's disease are associated with dysfunction in pericyte cells, which raises the question as to whether miniscule pieces of plastic, or a build-up of them in these cells, could bring about similar diseases. A question scientists are investigating.'
