Many decades after fluoride was first added to drinking water in some parts of the United States, there is still controversy about the possible health effects of drinking water fluoridation. Many people have strong views either for or against water fluoridation. Their concerns are based on everything from legitimate scientific research, to freedom of choice issues, to government conspiracy theories.

This is a review of the possible link between water fluoridation and cancer. Other possible health effects of fluoridation (positive or negative) are not addressed here. This is not a position statement of the American Cancer Society.

What is fluoride?

Fluorides are compounds that combine the element fluorine with another substance, usually a metal. Examples include sodium fluoride, stannous fluoride, and fluoride monofluorophosphate (MFP fluoride). Some fluorides occur naturally in soil, air, or water, although the levels of fluoride can vary widely. Just about all water has some fluoride. Fluoride is also found in plant and animal food sources.

Once inside the body, fluorides are absorbed into the blood through the digestive tract. They travel through blood and tend to collect in areas high in calcium, such as the bones and teeth.

How are people exposed to fluoride?

The major sources of fluoride for most people are water and other beverages, food, and fluoride-containing dental products (toothpastes, mouth rinses, etc.). Because dental products are generally not swallowed (except, perhaps, by younger children), they cause less concern for possible health issues.

Fluoride in drinking water

Water fluoridation began in some parts of the United States in 1945, after scientists noted that people living in areas with higher water fluoride levels had fewer cavities. Starting in 1962, the United States Public Health Service (PHS) recommended that public water supplies contain fluoride to help prevent tooth decay.

Fluoride is now used in the public drinking water supplied to about 3 out of 4 Americans. The decision to add fluoride to drinking water is made at the state or local level. The types of fluoride added to different water systems include fluorosilicic acid, sodium fluorosilicate, and sodium fluoride.

Natural drinking water sources in the US also have some fluoride in them, although the levels are much higher in some places than in others.

Is Fluoride in Drinking Water Safe?

A study published in JAMA Pediatrics has given new life to a long-running debate: whether adding fluoride to drinking water is a prudent way to prevent tooth decay, or a potentially toxic mistake.

The research, which focused on mother-child pairs from six Canadian cities, found that high fluoride exposure during pregnancy was correlated with lower IQ scores among young children, especially boys.

“Based on the current evidence, it is a reasonable recommendation to tell women to reduce their fluoride intake during pregnancy,” says study co-author Christine Till, an associate professor of psychology at York University in Toronto.

This documentary investigates the theory that the addition of fluoride to our drinking water is not as beneficial to dental health as originally thought, and may, in fact, be one of the causes of a cornucopia of neurological diseases that have arisen over the last several decades in America