Drinking just one cup of tea brewed in a single-serving bag may expose you to billions of microplastic particles — substances that have been linked to a wide variety of health issues, like heart problems, fertility issues, and certain cancers.
Polypropylene was the worst offender, releasing about 1.2 billion particles of microplastics per milliliter (mL) of tea water, the study found. Cellulose released roughly 135 million particles per mL, and nylon-6 released about 8.2 million particles per mL.
“This is a lot, so if you drink a lot, you are exposed to a lot,” says Martha Gulati, MD, a professor and director of preventive cardiology at Cedars-Sinai in Los Angeles, who wasn’t involved in the new study.
Microplastics and nanoplastics are far too tiny to detect as you go about your daily life. Microplastics are less than 5 micrometers in size — thousands of times smaller than a grain of rice — and nanoplastics are below 1 micrometer. They are ubiquitous, too, and can be found in the food we eat, the water we drink, and the air we breathe.
How Worried Should You Be About Using Tea Bags?
“It is hard to know how worried people should be regarding exposure to microplastics in general, much less in their tea,” says Samantha Bear, a senior research scientist at SimpleLab, a water testing startup in Berkeley, California. Bear wasn’t involved in the new study.
She points out that this field of science is still new, and a lot of the evidence to date is based on findings from lab experiments and animal studies.
Still, “There is growing concern about the potential health impacts of ingesting microplastics because of their potential to cause effects in the gut microbiome and the hormonal system, inflammation, or increased cancer risk,” says Luz Claudio, PhD, a professor of environmental medicine and public health at the Icahn School of Medicine at Mount Sinai in New York City, who wasn’t involved in the new study.
“Even though this is a very active area of research and the full effects of microplastics in the body are not fully understood, we definitely don’t want to add to the already high exposure through regular tea consumption if we can avoid it, because this could lead to accumulation in the body over time,” Dr. Claudio says.
Dr. Gulati concurs: “I know we are at the earliest stages of understanding microplastics, but I recommend we avoid them as much as possible, given the data that is emerging,” she says.
How to Minimize Exposure to Microplastics in Tea
While it may be hard to completely avoid microplastics in your tea, there are steps you can take to limit your exposure, says senior study author Alba García-Rodríguez, PhD, an assistant professor at the Autonomous University of Barcelona in Spain.
“Loose-leaf tea is one of the most effective ways to minimize exposure to micro- and nanoplastics,” Dr. García-Rodríguez says. “By avoiding tea bags altogether, you eliminate the risk of plastic contamination from the bag itself.”
Your best bet to reduce exposure to microplastics with loose tea is by brewing it with stainless steel or glass infusers, García-Rodríguez advises. Another good option is brewing loose tea in a kettle and straining it afterwards to remove the leaves from your drink.
If you want to keep buying tea in disposable tea bags, look for plastic-free bags and don’t assume that organic tea is automatically risk-free, García-Rodríguez adds.
“While organic tea often refers to how the tea leaves are grown, it doesn’t necessarily guarantee that the tea bags are free of plastics,” García-Rodríguez says. “To avoid exposure, look for brands that specifically advertise plastic-free or biodegradable tea bags made from plant-based materials like paper, hemp, or cornstarch.”