A new study has revealed an unexpected beneficial effect of tea and herbal teas: the preparation of these drinks is able to remove a good percentage of heavy metals, such as lead and cadmium, from the water
Every day, millions of people around the world sip tea and herbal teas, certainly useful for the correct hydration of the body and with other beneficial effects depending on the type. Now, however, a new study, conducted by a team from Northwestern University, has revealed an unexpected effect of these drinks: preparing tea and herbal teas removes a significant part of the heavy metals from water.
The researchers found that The lead and cadmium ions present in drinking water bind to tea leaves during the infusion, being trapped in plant material. This process reduces the concentration of contaminants in the final drink, offering an unexpected benefit to those who regularly consume tea and herbal teas (especially in the places where the water is more at risk).
Vinayak P. Dravid, senior author of the study published on ACS Food Science & Technology, He said:
We are not suggesting that everyone starts using tea leaves as a water filter. In fact, we often use model experiments and modify several parameters to probe and understand the principles and scientific phenomena involved in the capture/release cycles of contaminants. For this study, our goal was to measure tea’s ability to absorb heavy metals. By quantifying this effect, our work highlights the unrecognized potential of the consumption of tea to passively contribute to the reduction of exposure to heavy metals in populations around the world.
Which types of tea work better
Scientists have tested different varieties of tea and herbal teas: black tea, green, oolong, white, chamomile and rooibospreparing watery solutions containing precise quantities of metals (such as lead, chromium, copper, zinc and cadmium) and then heating them at a temperature just under the boiling point. Subsequently, they added the tea leaves, leaving them to infuse for variable periods of time, from a few seconds up to 24 hours.
Once the infusion process is completed, the team measured the concentration of metals left in the water. By comparing the levels of metals before and after the addition of the tea leaves, they managed to calculate the quantity actually removed.
The results showed that:
Experiments have shown that A common cup of tea can remove about 15% of the lead present in the water. This effect becomes particularly relevant in areas with obsolete or particularly contaminated water systems.
Although it is not a replacement solution to water filters, this discovery could explain, at least in part, some long -term health benefits associated with tea consumption. For example, some research indicates that populations with a high consumption of tea tend to show lower rates of cardiovascular diseases and strokes.
