Japanese researchers have studied and verified the presence of fluorine in tea beverages, saying prolonged consumption of the drinks could weaken bones.
The researchers, including Tetsuo Shimmura, a senior scientist at Toyama Institute of Health in Toyama Prefecture, reported the existence of the chemical in beverages such as oolong tea and black tea at a July meeting of Japan Society for Biomedical Research on Trace Elements in Tokyo.
They confirmed the fluorine content in tea exceeds the standard for tap water in terms of density in about 70 percent of the 130 instances they analyzed.