A woman developed painful, weak bones after drinking gallons of instant iced tea every day for years, which filled her body with harmful levels of fluoride, according to a new report.

Fluoride is one of the substances that can help people in small doses, by preventing Tooth decay, but can hurt in much bigger doses, study author Dr. Michael P. Whyte of Washington University in St. Louis, Missouri told AMN Health.

Although doctors were initially puzzled by what was causing the woman’s condition, they eventually found out that she drank an immense amount of iced tea every day. Tests of different brands of instant iced tea showed that some contained potentially harmful levels of fluoride.

So Whyte asked himself, could other people be getting harmful amounts of fluoride from instant tea? “My rationale, in part, for reporting (this woman’s case) is yes, I think that there are,” he said.

He explained that plants used to make tea can accumulate fluoride because their leaves draw fluoride out of the ground water. In addition, fluoride can find its way into tea during processing, he noted.

People may also get too much fluoride if they consume enough tea made using teabags. What is “enough,” however, “remains to be defined,” Whyte noted.

He added that in many parts of Asia, people drink so-called “brick” tea, which is typically of poorer quality, and there are “hundreds of thousands” of drinkers have developed skeletal problems from too much fluoride.

In an interview, he explained that he met the patient when she came to see him because of an aching back. X-rays showed she had pockets of dense bone.

Eventually, the doctors diagnosed her with skeletal fluorosis, a condition in which fluoride penetrates bone and disrupts its structure, causing pain and increasing fracture susceptibility. In addition, toxic levels of fluoride stimulate the body to add new bone, but of poor quality.

The patient admitted that she typically drank 1 to 2 gallons of double-strength iced tea, and had done so for her entire adult life. Her urine also contained enough fluoride to cause problems in her bones, Whyte noted.

Since many regions add fluoride to water to improve dental health, Whyte and his team tested five brands of instant teas in un-fluoridated water, and at normal strength. They found that several exceeded government limits on the amount of fluoride that is safe for bottled drinks and water.

After the woman switched from iced tea to lemonade, levels of fluoride in her urine decreased markedly. After a few years, she felt “completely well,” Whyte and his team report in the American Journal of Medicine.

Whyte stressed that his tests of iced tea reflect only the amount of fluoride in “one city, one time, one shelf, one jar,” and the amount of fluoride present in instant teas will depend on a myriad of factors, including the amount of fluoride in the region’s water, and where on the hill the tea plant is picked.

However, one type of Lipton tea contained 6.5 milligrams of fluoride per liter, at normal strength. If people drink 1 liter of that specific tea at double-strength every day, after 10 years, they may start to develop skeletal problems, Whyte noted.

SOURCE: The American Journal of Medicine, January 2005.