Most nutrition studies focus on things like polyphenols, caffeine, or other chemicals released during brewing, but such research overlooks a unique aspect of tea: unlike most food and drink, tea leaves are not directly consumed, and the brewing process allows tea leaves to adsorb chemicals as well as release them—most notably heavy metal toxins like lead, arsenic, or cadmium. (Adsorption is when a substance adheres to the surface of something; absorption is when a material takes in a substance.)

Well, maybe I’ll start drinking tea.

    • @[email protected]
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      1412 hours ago

      The team found that cellulose tea bags work the best at adsorbing toxic metals from the water while cotton and nylon tea bags barely adsorbed any contaminants at all—and nylon bags also release contaminating microplastics to boot.

      Tea type and the grind level also played a part in adsorbing toxic metals, with finely ground black tea leaves performing the best on that score.

      But the most significant factor was steeping time: the longer the steeping time, the more toxic metals were adsorbed.

      • @[email protected]
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        1112 hours ago

        I’m glad I over- steep my tea, also started using loose leaf due to the microplastics found in many grocery store selections

        • @[email protected]
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          28 hours ago

          Not sure. If you’re following the guidelines suggested in the article you’ll want to avoid any plastic and look for paper/cellulose bags. It may say “Plastic-free” on the container.

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      310 hours ago

      cellulose bags do some absorbing too:

      The cellulose tea bag was found to have a higher binding affinity but a lower asymptotic limit compared with those of the tea itself. The different tea leaves had similar values for both Langmuir parameters, with the Lipton tea─which was finely ground, packaged tea─having slightly increased properties compared to those of the whole tea leaves. The higher values for the Lipton tea line up with subsequent experimentation on the effect of fineness