- ST. LOUIS, Mo -- Instant
tea, one of the most popular drinks in the United States, may be a source
of harmful levels of fluoride, researchers at Washington University School
of Medicine in St. Louis report. The researchers found that some regular
strength preparations contain as much as 6.5 parts per million (ppm) of
fluoride, well over the 4 ppm maximum allowed in drinking water by the
Environmental Protection Agency and 2.4 ppm permitted in bottled water
and beverages by the Food and Drug Administration.
-
- The discovery stemmed from the diagnostic investigation
of a middle-aged woman suffering from spine pain attributed to hyper-dense
bones. Testing for the cause of her symptoms revealed the patient had high
levels of fluoride in her urine. She then disclosed a high consumption
of iced tea--claiming to drink one to two gallons of double-strength
instant
tea throughout the day--which led the researchers to test for fluoride
content in several brands of instant tea available on grocery store
shelves.
-
- Each of the teas was tested as a regular-strength
preparation
in fluoride-free water, and each contained fluoride, with amounts ranging
from 1.0 to 6.5 parts per million. The study is reported in the January
issue of The American Journal of Medicine.
-
- "The tea plant is known to accumulate fluoride from
the soil and water. Our study points to the need for further investigation
of the fluoride content of teas," says Michael Whyte, M.D., professor
of medicine, pediatrics and genetics. "We don't know how much
variation
there is from brand to brand and year to year."
-
- In many communities in the United States, fluoride is
added to drinking water to help prevent tooth decay. However, the Public
Health Service indicates that the fluoride concentration should not exceed
1.2 ppm.
-
- Physicians have been aware that ingestion of high levels
of fluoride cause bone-forming cells to lay down extra skeletal tissue,
increasing bone density but also bone brittleness. The resulting disease,
called skeletal fluorosis, can manifest in bone pain, calcification of
ligaments, bone spurs, fused vertebrae and difficulty in moving
joints.
-
- "When fluoride gets into your bones, it stays there
for years, and there is no established treatment for skeletal
fluorosis,"
Whyte says. "No one knows if you can fully recover from
it."
-
- Americans are exposed to fluoride not only through
fluoridated
water but increasingly through fluoridated toothpastes and other dental
preparations. Pesticides, Teflon®-coated cookware, chewing tobacco,
some wines and certain sparkling mineral waters are more unusual sources
of excess exposure. Until now, instant tea had not been recognized as a
significant source of fluoride.
-
- According to Whyte, the findings could aid in the
diagnosis
and treatment of patients who have achiness in their bones. In the future,
doctors should ask such patients about their tea consumption.
-
- Contact Gwen Ericson
- ericsong@wustl.eduericsong@wustl.edu
-
- Washington University School of Medicine
- http://medinfo.wustl.edu/
-
- http://www.eurekalert.org/
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