Flavor augmentations affect fluoride bioavailability from brewed dark tea

Fluorosis caused by consumption of dark tea is a major public health problem in the western part of China. In this study, the effects of milk powder, butter, and table salt on the bioavailability of the fluoride in an infusion of dark tea were investigated in a rat model. These substances were examined for their potential as dietary interventions to reduce the risk of tea-induced fluorosis. Fluoride was less bioavailable from the dark tea infusion than from a NaF solution. The addition of milk powder significantly decreased the amount of fluoride absorbed from the dark tea infusion and increased the amount of fluoride in fecal excretion. While butter had a limited effect on fluoride bioavailability, it prolonged the fluoride absorption period. The addition of 4 mg/mL table salt significantly increased the bioavailability of fluoride in the dark tea infusion. The addition of different flavor augmentations to a dark tea infusion had different effects on fluoride bioavailability. Therefore, dietary intervention may be a novel strategy for reducing fluorosis risk.