Surprising health benefits of drinking tea – it removes lead from water

Scientists from Northwestern University have discovered surprising properties of tea. It turns out that tea not only tastes good and has antioxidant effects, but it can also remove heavy metals such as lead and cadmium from water. This groundbreaking discovery could be crucial for people exposed to contaminated drinking water.

Tea as a natural filter for heavy metals

Researchers conducted a series of experiments that demonstrated tea leaves’ ability to adsorb heavy metals from water. During the brewing process, metal ions such as lead and cadmium attach to the surface of the leaves, remaining there until the tea leaves are removed.

How does tea purify water? Study procedure

Researchers began by preparing water solutions deliberately contaminated with heavy metals, such as lead and cadmium, at concentrations corresponding to levels found in polluted water sources. They then heated the water to about 95°C – the typical brewing temperature for tea – and added various types of tea. After completing the experiment, they conducted a chemical analysis of the water to determine the remaining metal content.

The results? Tea demonstrated the ability to adsorb heavy metals, acting as a natural filter and effectively reducing their concentration in the solution.

Black tea is the most effective: why does it remove heavy metals best?

To determine which type of tea has the best adsorption properties, scientists tested three varieties: loose black tea, green tea, and tea in bags. It turned out that finely ground black tea was the most effective in removing metals. While green tea also exhibited the ability to bind metals, its effectiveness was lower.
Tea in bags, although convenient to use, ranked the lowest – probably due to the smaller surface area of the leaves and their limited contact with the water. Researchers attribute black tea’s advantage to its chemical structure and fermentation process, which may enhance the leaves’ ability to capture metal ions.

How does longer brewing remove more toxins?

Another key finding from the study is that brewing time directly affects the efficiency of removing heavy metals. In a standard test using one cup of water (about 250 ml) and tea brewed for three to five minutes, researchers found that lead levels dropped by about 15% – even when the initial concentration reached 10 parts per million, a value found in highly polluted water.

When the brewing time was extended, the percentage of metals removed increased. Scientists observed that longer contact of tea leaves with water allows for better binding of heavy metal ions, suggesting that patience when brewing tea can bring significant benefits.

Proportions and temperature increase tea’s effectiveness

The study also showed that the more tea leaves used relative to the volume of water, the more heavy metals were removed.

Water temperature also played an important role – all experiments were conducted under conditions similar to home brewing, meaning the water was heated to about 95°C. Researchers emphasize that these conditions are easily achievable in daily life, making the method practical. Water at a lower temperature was not tested, but scientists suspect it could reduce adsorption efficiency.

Health benefits of drinking tea in everyday diet

The study demonstrated that the tea brewing process can improve the quality of drinking water by reducing the concentration of toxic heavy metals. Substances such as lead and cadmium accumulate in the body, leading to serious health consequences, including kidney damage, neurological disorders (such as reduced IQ in children), hypertension, and anemia. Moreover, experiments have shown that longer brewing time and a higher amount of tea leaves increase the effectiveness of water purification, opening up possibilities for the practical application of this method on a larger scale.

Scientists see this process as a potential solution for regions with limited access to clean drinking water. While this method will not replace modern filtration systems, its simplicity and accessibility make it a valuable tool in the fight against water contamination.