Tea (Camellia sinensis) leaves accumulate higher levels of Aluminum: Potential Health Risk- Alzheimer’s disease (AD): An updated review of evidence

This review paper of literature highlights the role of accumulation of aluminum in tea leaves and its toxic effects on human health. Tea is the most consumed beverage in the world after water and contains heavy metals and trace elements that may cause potential negative effects on health. Tea is known to be a metal accumulator. However, drinking even a very high dietary amount of black tea or green tea would be unlikely to cause these adverse effects in humans. Thus, for the majority of heavy tea drinkers around the world, tea is likely to be the largest single source of aluminum intake. Addition of milk to tea can decrease or completely inhibit tea antioxidant properties. According to the literature survey, it is well known that the tea plant accumulates aluminum in its leaves to a greater extent than most other edible plants, and would be a potentially important source of dietary aluminum. Aluminum can be transferred into tea infusions through brewing tea, then enter the human body via tea drinking, thereby causing potential harm to human health. On the basis of literature survey, even though some epidemiological reports were contradictory, there was mounting scientific evidence suggesting a relationship between the neurotoxicity of aluminum and the pathogenesis of Alzheimer’s disease. In particular, the link between aluminum and Alzheimer’s disease has been the subject of scientific debate for several decades. The literature survey confirmed that aluminum hypothesis has been the subject of much debate and criticism for several decades. Evidence from human clinical trials suggested that moderate (1–6 cups/day) rather than excessive consumption of tea could bring diverse health benefits. The relationship between tea consumption and dementia has not been well established yet and other studies reported no significant association. The cause of Alzheimer's disease and any association with aluminum is still unknown. There have been conflicting findings in the scientific literature.