Tea leaves can remove heavy metals such as lead, cadmium and chromium from water. And steeping time has the biggest impact.
Brewing tea could help to remove toxic heavy metals, including lead, from drinking water, a new study has revealed. A good cup of tea has long been associated with numerous slight health benefits, but previous studies have tended to focus on the effects of chemicals in the tea leaves that are released during brewing. Now, a new study has revealed that the brewing process removes charged atoms (called ions) from heavy metals in water, seemingly by chemically bonding with them. This, in turn, makes the heavy metals stick to the tea leaves, pulling them from the water. The study was published Monday (Feb. 24) in the journal ACS Food and Science Technology . "We're not suggesting that everyone starts using tea leaves as a water filter," co-author Vinayak Dravid , a professor of materials science at Northwestern University, said in a statement . "Our goal was to measure tea's ability to adsorb heavy metals. By quantifying this effect, our work highlights the unrecognized potential for tea consumption to passively contribute to reduced heavy metal exposure in populations worldwide." Related: Boiling tap water can remove nearly 90% of all microplastics, new study finds More than 5 billion cups of tea are drunk each day, making it second only to water as the most consumed drink on the planet. Scientists have long studied the health impacts of green and black teas, and the brew has been tied to lower risks of cancer , stroke , and death due to cardiovascular disease . But exactly why a cup of English breakfast confers these benefits is unclear. Past research linked these benefits to the chemicals released in the plants, but the…