This article is from He Xiaosheng's blog: http://hexiaosheng03752.blog.sohu.com/106208338.html
Tea is a representative of China's ancient dietary culture, and the Chinese custom of drinking tea has a long history.
Classification of Tea
Teas can be divided into unfermented green tea, semi-fermented Tieguanyin and oolong tea series, and fully fermented black tea.
A recent study by the Tea and Health Research Laboratory at the Institute of Clinical Pharmacology, Central South University, indicates that long-term consumption of certain black tea bags can cause combined fluoride and aluminum poisoning. This not only damages teeth and bones but also impairs the hippocampus, the brain region responsible for memory, leading to presenile dementia.
During the fermentation process of black tea, chemical reactions occur that increase the levels of fluoride and aluminum. Some coarse and old tea leaves, after fermentation, have alarmingly high concentrations. Professor Luo Zemin, a doctoral supervisor and professor at the College of Life Sciences, Hunan Agricultural University, believes this research reveals the damage caused by long-term consumption of tea with high concentrations of fluoride and aluminum, offering strong guidance for healthy tea drinking. This is similar to avoiding fluoride toothpaste and not cooking in aluminum pots, as these practices can affect cognitive function and lead to dementia symptoms.
The black tea bags we commonly drink are mostly made from broken black tea. To date, various countries and international organizations have not established standards for fluoride and aluminum content in tea bag raw materials. This allows tea bag manufacturers to use coarse, old tea leaves without restriction to reduce costs and increase profits.
Currently, black tea sold on the international market is mainly in three forms: black loose leaf tea, broken black tea, and tea bags.
Li Yi, a master's student at the Tea and Health Laboratory, Institute of Clinical Pharmacology, Central South University, conducted an experiment by dividing 6-month-old rats into three groups: a brick tea group, a black tea group, and a control group. The study observed the effects of consuming fluoride and aluminum from black tea bags on the rats' hippocampal structure and their neurobehavior. The results showed that long-term consumption of black tea bags made from coarse, old tea leaves can cause brain damage in animals. This study successfully replicated a model of combined fluoride and aluminum poisoning in rats for the first time in the world.
Therefore, I personally believe that if you drink tea, you should choose to brew it with whole tea leaves yourself. Green tea, oolong tea, Tieguanyin, and Pu'er are all excellent choices. Try to avoid drinking tea bags for convenience to reduce your intake of fluoride and aluminum, thereby minimizing harm to your brain.