Tea has naturally high fluoride levels. Excess fluoride can weaken bones and discolor children's un-erupted teeth. When fluoridated water is used to make tea, fluoride levels consumed can be health damaging.
Four cups, of 20 teas sampled, delivered 0.8 to 1.8 mg of fluoride, when non-fluoridated water was used, reports Cao et al. in Food Chemistry.
"Among populations habitually consuming black tea, water fluoridation is not only unnecessary but also possibly harmful"-The target organs of chronic fluoride intoxication are not only the teeth and skeleton, but also the liver, kidney, nervous and reproductive systems,"- they write.
A March 2008 Food and Chemical Toxicology study found up to 4.5, 1.8, and 0.5 mg/L fluoride in black, green and white teas, respectively, when brewed for 5 minutes (61 teas sampled).
Brewed teas could contain up to 6 mg/L fluoride depending on the amount of dry tea used, the water fluoride concentration and the brewing time, according to the American Dental Association (ADA).
According to 1997 ADA data, 3 and 4 milligrams daily is adequate for women and men, respectively, to prevent fluoride's adverse effects. It's much lower for children. In 2006, the National Research Council reported the basis for those levels should be reduced.
Case Reports by Cao and Yi in the Journal of Fluorine Chemistry (February 2008) "Tea and fluorosis:"-
--A 57-year-old Englishman's misdiagnosed Paget's disease (weakened bones) with osteoarthritis was finally correctly diagnosed as skeletal fluorosis caused by his long-term heavy tea-drinking habit.
--A Pakistani woman's dental fluorosis resulted solely from tea which she consumed from age two.
--A 36-year-old Chinese woman's ten-years of joint pain disappeared when she stopped drinking tea.
--French doctors identified 5 patients who developed bone softening (osteomalacia) from drinking tea.
-- An American woman's fluoride-caused debilitating joint pains disappeared when her two-gallon-a-day iced-tea habit stopped.
"By 2020, one in two Americans over age 50 will be at risk for fractures from osteoporosis or low bone mass," according to the Surgeon General.
"It's clear that fluoridation is increasing Americans' bone damage; but US physicians are not trained to diagnosis fluoride-caused disease. Presidential and other candidates must pledge to stop water fluoridation if they truly care about individuals and not fluoridation-supporting special interest groups such as the American Dental Association,"- says attorney Paul Beeber, President, New York State Coalition Opposed to Fluoridation, Inc. "Meanwhile the Tea industry needs to label the fluoride content of their products."
Fluoride is in many foods as determined by the USDA http://www.ars.usda.gov/Services/docs.htm?docid=6312
According to American Dental Association, the adequate intake of fluoride to avoid moderate fluorosis (yellow teeth) is:
-- 0.01 mg/day for 0 to 6-month-olds
-- 0.5 mg/day for 7 through 12 months
-- 0.7 mg/day for 1 to 3-year-olds
-- 1.0 mg/day for 4 to 8-year-olds
Mild fluorosis is white spots, lines or blotches to the teeth and can occur at levels lower than the above.
The CDC reports that fluorosis afflicts up to 48% of US school children - 4% of it severe.
Both the ADA and CDC advise that infant formula should not be mixed with fluoridated water.
Food Chemistry, "Safety evaluation on fluoride content in black tea," by Cao et al. (November 2004)
Food Chemical Toxicology, "Assessment of fluoride concentration and daily intake by human from tea and herbal infusions," by Malinowska et al. (March 2008)
Journal of Fluorine Chemistry, "Tea and fluorosis," by Juan Yi and Jin Cao (February 2008