The fluoridation of the American water supply started in 1951. The rationale was that fluoride would help to prevent cavities. Today, it’s estimated that about 62% percent of the U.S. population receives fluoridated water.
Many have questioned the safety of this practice, fearing that fluoride may do more harm than good. And in some countries, the fluoridation of water has been banned.
A recent study, published in the Journal of Epidemiology and Community Health shows fluoridation may be linked to low thyroid function. Low thyroid function, in turn, was linked to depression.
Previous studies associate fluoride to reduced thyroid function, but few population studies have been conducted. About 10% of the English water supply is fluoridated, prompting researchers in Europe to investigate the association between fluoridation and thyroid disease.
For the current study, fluoride levels in drinking water were measured in two English cities and compared to rates of hypothyroidism. Researchers found that individuals living in West Midlands (a fluoridated area) were twice as likely to suffer hypothyroidism compared to Greater Manchester, a non-fluoridated area.
Fluoride displaces iodine, which the thyroid needs to produce thyroid hormone. Inadequate levels of iodine may lead to symptoms of hypothyroidism.
Interestingly, some medical approaches to treat hyperthyroidism (overactive thyroid) utilize fluoride to lessen thyroid activity.
Almost all water contains a natural form of fluoride, but usually in minute quantities. Fluoride is also naturally present in soil.
The decision to fluoridate water varies between counties within the United States, with some banning the practice altogether. You can investigate the fluoride status of your county by contacting your local water or health department.
Certain filters can help to remove fluoride from water. An organization called the Fluoride Action Network recommends reverse osmosis, deionizers that use ion-exchange resin, and activated alumina filters. Note that the more popular water filters like Brita do not remove fluoride.
By Maylin Rodriguez-Paez RN at Life Extension