A recent study published in the Journal of Epidemiology & Community Health found that water fluoridation may increase the risk for hypothyroidism an underactive thyroid. It was one of the largest studies to examine the link between water fluoridation and hypothyroidism, drawing upon data gathered from several general medical practices throughout England.
The study discovered that communities with fluoridated water were 30 percent more likely to have high levels of hypothyroidism than communities without fluoridated water. Hypothyroidism is a disorder which occurs when the thyroid doesnt produce enough hormones. Symptoms of hypothyroidism include fatigue, depression and even memory loss.(1)
Fluoride is added to approximately 10 percent of Englands drinking water. By contrast, fluoride is added to two-thirds of Americas tap water supposedly to prevent cavities. However, there is a growing amount of evidence suggesting that fluoride does more harm than good. In addition, there is little evidence to suggest that communities with fluoridated water have fewer cavities than communities without fluoridated water.(2)
Fluoridated vs. non-fluoridated communities
The researchers compared the English city of Birmingham, which adds fluoride to its drinking water, to the city of Manchester, which doesnt add fluoride to its drinking water. The researchers found that doctors offices in Birmingham were twice as likely to encounter hypothyroidism than doctors offices in Manchester.
It raises a red flag, said Dr. Philippe Grandjean, an environmental health researcher and physician at Harvard University, that possible interference with thyroid function needs serious consideration when regulating fluoride levels in drinking water.(1