Some people who often drink tea like to have a thick layer of "tea scale" in their teacups, seemingly to show that they are "tea lovers". Even some people believe that brewing tea with teaware that has tea scale makes the tea more flavorful. In fact, tea scale is extremely detrimental to human health. Therefore, medical experts have issued a warning: those who drink tea frequently should not forget to clean their cups frequently.
Scientific research shows that in a humid environment, tea will quickly oxidize to form brown tea rust, which contains various harmful metals such as cadmium, lead, mercury, and arsenic. Unfinished tea or tea that has been stored for a long time, when exposed to the air, the tea polyphenols in the tea leaves undergo an oxidation reaction with the metal substances in the tea rust, forming tea scale that adheres to the inner walls of the teaware. This layer accumulates over time and poses a clear threat to human health. Some people have conducted chemical analyses of tea scale samples and found that it also contains certain carcinogenic substances, such as nitrites. As tea drinkers frequently drink tea, the tea scale continuously enters their digestive systems, where it is highly likely to combine with proteins, fatty acids, vitamins, and other substances in food to form various harmful compounds. This not only hinders the human body's absorption and digestion of nutrients in food but also damages many internal organs.
Therefore, if you drink tea frequently, you should also clean your cups frequently. For teacups with long-standing tea scale deposits, you can remove them completely by scrubbing repeatedly with toothpaste. For teapots with tea scale, you can clean them by heating with rice vinegar or soaking with baking soda for a whole night, followed by repeated rinsing and shaking.