Fact: According to generally accepted scientific knowledge, there is no association between cancer rates in humans and optimal levels of fluoride in drinking water.

Since community water fluoridation was introduced in 1945, more than 50 epidemiologic studies in different populations and at different times have failed to demonstrate a link between fluoridation and the risk of cancer.

A 2011 study in the Journal of Dental Research found no significant association between bone fluoride levels and osteosarcoma, a rare, primary malignant bone tumor that is more prevalent in males.

The case-control study was led by the Harvard University School of Dental Medicine and approved by the National Cancer Institute.

Fluoride concentration was measured in samples of normal bone that were adjacent to a person’s tumor. Because fluoride naturally accumulates in bone, this method provides a more accurate measure of cumulative fluoride exposure than relying on the memory of study participants or municipal water treatment records.

Source: The American Dental Association Fluoride Facts and National Cancer Institute