August 13/Islamabad, Pakistan/Right Vision News -- A new research has shown that black tea contains higher concentrations of fluoride than previously thought. The additional fluoride from drinking two to four cups of tea a day will not harm anyone; it is the very heavy tea drinkers who could get in trouble, BBC reported.
Most published reports show 1-5mg of fluoride per liter of black tea, but the new study shows that number could be as high as 9mg.