Fluoride Content in Infusions of Selected Teas Available on the Polish Market-An In Vitro Study

This study aimed to evaluate the fluoride content and other key physicochemical properties in commercially available black tea infusions, with a focus on tea form and geographic origin, in order to assess their contribution to total dietary fluoride intake.

A total of 121 black tea samples were analyzed, including 66 loose-leaf, 42 bags, and 13 pyramid-bag teas. Infusions were prepared using standardized brewing protocols. Fluoride concentrations were determined with an ion-selective electrode, while the pH, buffer capacity, titratable acidity, calcium, and inorganic phosphorus were also measured. Statistical analysis included ANOVA, Tukey post hoc tests, and Pearson correlation analysis.

Fluoride content varied significantly by tea form and origin. Infusion of tea bags exhibited the highest fluoride, calcium, and acidity levels, while loose-leaf teas had the lowest. Teas from Africa contained approximately twice as much fluoride as those from Central or East Asia. Significant correlations between fluoride, calcium, and phosphorus were observed, particularly in tea-bag infusions, suggesting processing influences mineral release.

Black tea, particularly in bag form and sourced from African regions, may significantly contribute to daily fluoride intake. Given the potential to exceed recommended fluoride thresholds, especially in individuals consuming multiple cups daily or living in fluoridated areas, these findings underscore the importance of consumer awareness and possible product labeling to guide safe consumption.