Leaching and in vitro bio-accessibility of aluminium from different teas

To assess human exposure to aluminum (Al) from tea, the total Al contents in different teas (green tea, black tea and oolong tea processed with same fresh leaves) and the leaching of Al from these teas were analyzed, and the bio-accessibility of Al from these teas and their infusions was evaluated under simulated gastrointestinal condition. The results showed that green tea contained a high level of Al, but the leaching rate of Al from it was low, and the brewing condition significantly affected the leaching rate. It was also found that the leaf age significantly affected the content of Al in tea, but no significant differences were observed in the Al content among different teas and in the Al leaching from these teas. Results also showed that the bio-accessibility of Al from green tea infusion was very low after simulated gastrointestinal digestion, and there were no significant differences in the bio-accessibility of Al from different tea infusions. It is concluded that drinking tea is relatively safe and it is no cause for concern about Al toxicity in healthy individuals.