A recently published study by researchers at the University of Derby in the UK has found that certain economy tea blends sold by leading supermarkets contain levels of fluoride that could adversely affect health.
The researchers looked at fluoride levels in a range of teas on retail sale using Ion Selective Electrode analysis. The results ranged from 93 to 820 mg/kg in dry teas and from 0.43 to 8.85 mg/L in infusions. The lowest levels were found in single variety teas, while branded blends also had relatively low levels. However, some supermarket own brand economy teas showed much higher levels.
The authors of the study conclude that these high levels indicate the use of mature leaves of the tea plant (Camellia sinensis), which accumulates fluoride from the soil as it grows. They also voice concerns over potential health effects, stating that their result indicate that anyone drinking a litre of these teas each day could be exposed to 75-120% of the dietary reference intake of 4 mg/day of fluoride.
Too much fluoride in the diet can cause fluorosis in teeth and bones, with possible damage and pain in bones and joints through calcification. The authors suggest that economy teas should be labelled to indicate fluoride levels.
The study is published in the journal Food Research International and an abstract can be found here.