Science, Society, Sustainability
The ISIS website is archived by the British Library as UK national documentary heritage ISIS members area log in ISIS facebook page ISIS twitter page ISIS youtube channel ISIS vimeo channel

ISIS Press Release 22/01/07

Fluoride in Tea

Dr. Mae-Wan Ho replies

A fully referenced version of this article is posted on ISIS members’ website. Details here

Several readers alerted us to the problem of fluoride in tea after the circulation of our recent article [1] Green Tea, The Elixir of Life? Fluoride is a known systemic poison, and there is massive opposition to government policy in fluoridation of public drinking water supplies worldwide [2] ( No to Fluoridation , SiS 25).

Researchers at Washington University School of Medicine in St. Louis Missouri found that instant tea preparations contain 1 to as much as 6.5 ppm of fluoride (1 to 6.5 mg per litre of tea) [3, 4]. The US Environmental Protection Agency allows 4 ppm maximum in drinking water, based on their calculations that it takes at least 20 mg of fluoride a day everyday for 20 years to produce crippling skeletal fluorosis. But the Food and Drug Administration permits 2.4 ppm in bottled water and beverages, while the Public Health Service says it should not exceed 1.2 ppm in drinking water.

The World Health Organisation recommends optimum levels of 1-1.2 ppm, and an upper limit of 1.5 ppm. The 1 ppm level of fluoride in UK water supplies deemed safe by the government is already 100 times that in mother's milk [2], and fluoride, like most toxins, is particularly harmful for infants.

The discovery of fluoride in tea stemmed from a woman diagnosed with skeletal fluorosis in 1998 by Dr. Michael P. Whyte [4], a bone specialist at Washington University. The disease afflicts people in remote regions of Tibet, Mongolia and China, in which fluoride replaces calcium in the bones. The bones become dense, weak and brittle, and sometimes the ligaments harden and changes bone structure, causing pain and crippling.

The 52 year-old drank huge amounts of tea, one to two gallons of double-strength instant tea every day of her adult life. Studies in Tibet and other areas where people drink large amounts of brick tea have shown that the beverage can be a significant source of fluoride. Brick tea is made from mature leaves, berries and twigs of the tea plant, which often contain high levels of fluoride absorbed from the soil, and instant tea tends to be made from brick tea.

Whyte tested the woman's tea and found that her beverage added 26-52 mg of fluoride to her diet each day, besides the water she used to make the tea, which contained 2.8 ppm. By Whyte's calculation, the woman drank a total of 37 - 74 mg of fluoride a day.

Whyte said consumers should not be alarmed by the results, and that the amount of fluoride in tea fluctuates from batch to batch even from the same manufacturer. The woman drank to unusual excess and her symptoms improved over a five-year period once she stopped drinking tea and switched to lemonade.

Dr. Michael Kleerekoper, a professor of medicine at Wayne State University in Detroit said most tea drinkers have nothing to fear, and drinking tea within normal limits will probably not cause any health problems.

Tea can become very high in fluoride because tealeaves, especially older leaves accumulate more fluoride from pollution of soil and air than any other edible plant. Fluoride content in tea has risen dramatically over the past 20 years due to industry contamination [2, 5]. Recent analyses have revealed a fluoride content of 17.25 mg per teabag or cup in black tea and 22 gm per teabag or cup in green tea. Aluminium content was also high, over 8 mg. Normal steeping time is five minutes, and the longer a tea bag is steeped, the more fluoride and aluminium were released. After ten minutes, fluoride and aluminium almost doubled.

To get the maximum health benefits from green tea, we should continue to oppose fluoridation in water [2] while organic cultivation in non-polluted soils is essential. Leaf tea, especially young leaves and shoots should be used rather than teabags or instant tea. A requirement for routine analysis and listing of fluoride, aluminium and other heavy metals in tea labels would do much to protect consumers from harm while enjoying its health benefits [1].


Recommended Reading


sitemap | contact ISIS

© 1999-2016 The Institute of Science in Society