Introduction
Brewing tea is a daily ritual for millions, often praised for its calming effects and health benefits. But beyond the antioxidants and soothing warmth, new research suggests a surprising role: tea might help protect us from toxic heavy metals found in drinking water. Scientists have discovered that the process of steeping tea can actually reduce contaminants like lead, opening new doors for simple and sustainable ways to enhance public health
Remove Heavy Metals from Water
Brewing tea isn’t just a comforting ritual — it may also play an unexpected role in protecting public health. According to a new study from Northwestern University, tea leaves can adsorb heavy metals like lead from water, potentially reducing exposure through a simple cup of tea.
The Hidden Benefit of Brewing Tea
Although tea is known for its antioxidants and links to reduced stroke and dementia risk, scientists now suggest a different benefit: brewing tea might help remove toxic contaminants. In experiments, black tea brewed for five minutes removed around 15% of lead ions in water.
Even in areas with low contamination, this process might still make a difference. “On the margins, tea consumption is reducing metal intake by a very small amount,” said Benjamin Shindel, lead author of the study. Across populations, that small effect might influence disease rates linked to heavy metal exposure.
Different Teas, Different Results
To test this idea, the team brewed several types of tea — black, green, white, oolong, chamomile, and rooibos — in water containing measured amounts of heavy metals. They also compared loose-leaf teas to commercial tea bags.
Results showed that true teas like black, green, and white were better at adsorbing lead than herbal types. Brewing tea for longer intervals, up to 24 hours, significantly improved its ability to capture contaminants.
Do Tea Bags Matter? Yes — Especially Cellulose
Surprisingly, even the bag itself had an impact. When tested without tea, cellulose tea bags removed more metals than cotton or nylon ones. Why? It’s all about surface area. Cellulose, derived from wood pulp, offers more binding sites for metal ions compared to synthetic materials.
“Nylon tea bags are already problematic because they release microplastics,” Shindel said. “But most modern bags are made from cellulose, which only releases fibers the body can process.”
Grinding, Surface Area, and Steeping Time
Tea structure also mattered. Finely ground black tea absorbed more lead than whole leaves due to increased surface area. When leaves are processed into black tea, pores open up and create more space for metal ions to attach.
But among all variables, brewing time made the biggest difference. The longer the tea steeped, the more heavy metals were captured. Steeping overnight — like in cold-brew or iced tea — provided the highest removal levels.
“Any tea with longer steeping or higher surface area will remove more metals,” Shindel said. “People who brew tea for just a few seconds won’t see this benefit.”
A Public Health Angle to Brewing Tea
From a health perspective, brewing tea for 3–5 minutes can remove up to 15% of lead in a standard cup — even at levels as high as 10 parts per million. That’s a meaningful reduction, especially where clean water access is limited.
While brewing tea won’t solve large-scale contamination, it offers a simple, low-cost method that may benefit communities. Chemistry professor Michelle Francl noted, “It suggests some interesting directions for sustainable water purification.”
Future Research and Broader Impact
Shindel emphasized that results depend on factors like steeping time and tea-to-water ratios. But even small changes could affect public health outcomes.
“If people drink an extra cup of tea a day, maybe we’ll see declines in illnesses tied to heavy metals,” he said. “It might even help explain why high tea-drinking populations show lower heart disease and stroke rates.”
Ultimately, brewing tea might offer more than flavor and comfort — it could become a quiet hero in everyday environmental health
Conclusion
While brewing tea won’t replace advanced water treatment, its ability to reduce heavy metals in water adds a valuable layer to its benefits. This everyday habit might offer a subtle but meaningful defense against environmental toxins. As research expands, a simple cup of tea could become part of the conversation on public health and sustainable water practices.
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References
Brewing tea removes heavy metals from water, study finds
https://www.theguardian.com/science/2025/feb/25/brewing-tea-removes-heavy-metals-water-study
Brewing tea removes lead from water https://news.northwestern.edu/stories/2025/02/brewing-tea-removes-lead-from-water/
