It's rare to hear any negatives about tea. The beverage comes with a host of wellness benefits, including weight loss and brain health, and drinking this beverage won't fill you up on caffeine like coffee will. However, tea bags are now in the hot seat, as new research shows they can release billions of microplastics into your mug of hot water.
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Tea bags release billions of microplastics, a new study finds.
According to a new study by the Mutagenesis Group of the UAB Department of Genetics and Microbiology, published in the journal Chemosphere, three commercial tea bag brands released three different micro and nanoplastics (MNPLs)—nylon, polypropylene, and cellulose. (The specific tea brands were not disclosed.)
"The UAB researchers observed that when these tea bags are used to prepare an infusion, huge amounts of nano-sized particles and nanofilamentous structures are released, which is an important source of exposure to MNPLs," explains a press release.
The researchers simulated brewing tea and found that billions of these MNPLs were produced—1.2 billion particles per milliliter of polypropylene, 135 million particles per milliliter of cellulose, and 8.18 million particles per milliliter of nylon-6.
As Good Housekeeping previously noted, polypropylene is often used to seal paper tea bags. Some tea bags that are marketed as "mesh" are even made entirely of woven nylon or polyester: "They release a huge number of microplastics and are not biodegradable," the magazine says.
And these microplastics are absorbed by intestinal cells.
Next, the researchers exposed the particles to human intestinal cells and found that "mucus-producing intestinal cells had the highest uptake of micro and nanoplastics, with the particles even entering the cell nucleus that houses the genetic material," the press release explains.
This is concerning because the microplastics can then enter the bloodstream, spreading throughout the body.
"It is critical to develop standardized test methods to assess MNPLs contamination released from plastic food contact materials and to formulate regulatory policies to effectively mitigate and minimize this contamination. As the use of plastic in food packaging continues to increase, it is vital to address MNPLs contamination to ensure food safety and protect public health," the researchers said in response.
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Why are microplastics so concerning?
According to Harvard Medicine magazine, microplastics are "particles smaller than 5 millimeters that slough off plastic as it degrades." They can be found in everything from cosmetics and cleaning products to produce and seafood.
Furthermore, as the new study notes, "Food packaging is a major source of micro and nanoplastic (MNPLs) contamination and inhalation and ingestion is the main route of human exposure."
Scientists are still trying to determine exactly how much of these particles remain in our bodies. However, Bernardo Lemos, an adjunct professor of environmental epigenetics at the Harvard T.H. Chan School of Public Health, said in an. interview with Harvard Medicine, “We are seeing more data that suggest microplastics affect human biology."
Here are a few examples:
A 2022 study found that microplastics "can affect male semen quality and...may significantly impact male fertility."
A 2023 study found that polypropylene microplastics (the type found most in tea bags) "enhances metastasis-related gene expression and cytokines in breast cancer cells, exacerbating breast cancer metastasis."
Finally, a study published just last week suggests that microplastics might be linked to colon cancer and lung cancer.
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How can you stay safe?
Tracey Woodruff, PhD, a Professor of Obstetrics and Gynecology and Reproductive Sciences at UC San Francisco, who has been studying microplastics for more than three decades, shared with the school how people can limit their exposure to the toxins.
For one, Woodruff doesn't microwave in plastic. "Heat makes plastic release harmful chemicals like BPA so I always microwave in ceramic or glass," she said. She also only uses glass or stainless steel water bottles.
"I buy organic as much as possible to reduce our exposure to pesticides," she said, adding that she also limits her consumption of red meat since "many chemicals like to hang out in fatty food."
And since a lot of commercially available cleaning products contain microplastics, Woodruff makes her own solution using baking soda and water or vinegar.
You can also opt for loose-leaf tea or certain plastic-free brands.
One simple way to avoid the microplastics in tea bags is to use loose leaf tea and a stainless steel infuser or tea strainer.
Certain tea bag brands also have gone plastic-free. According to the Center for Environmental Health and the website I'm Plastic Free, they are the following (though Best Life has not independently confirmed these claims:
- Bromley
- Pukka
- Numi Teas
- Republic of Tea
- Stash
- Yogi Tea
- Higher Living
