One of the greatest sources of food- and beverage-borne fluoride is tea. One study found concentrations of 50-125 ppm [parts per million] in fifteen varieties of tea, a dramatic rise in just the last two decades. A polish study found levels up to 340 ppm in sixteen varieties of teas. Why tea? Because some plants ten to accumulate fluoride in greater concentrations than others.
Dr. Russell Blaylock, Health and Nutrition Secrets That Can Save Your Life, pg. 124.
By comparison, the EPA’s upper limit for fluoridated water is 4 parts per million (and even THAT’S high for this notorious toxin that causes cancer, skeletal fluorosis, osteoporosis, infertility in men, and dental fluorosis).
Alternatives: Tea grown in Japanese soil is said to be devoid of fluoride. Additionally, herbal teas have much smaller amounts of fluoride than green tea, and Yerba Mate has been shown to have about 1/5th the fluoride of green tea.