Fluoride Exposure and Its Health Risks: What Does Recent Science Reveal?

A new meta-analysis published in the Annual Review of Public Health has raised alarms about the potential harmful effects of fluoride on health, especially in pregnant women and children. 

Researchers emphasize that systemic exposure to this substance could negatively impact cognitive development, thyroid function, and bone strength.

In countries such as the United States, Canada, the United Kingdom, Australia, and Ireland, it is common practice to add fluoride to drinking water at a rate of 0.7 milligrams per liter, a measure implemented since the mid-20th century to prevent tooth decay.

Between 1940 and 1970, studies showed that this practice reduced the incidence of cavities in children by up to two-thirds. However, the risks associated with prolonged fluoride intake are being re-evaluated by the scientific community.

Effects of fluoride on the human body

Once ingested, fluoride is rapidly absorbed by the stomach and intestines, reaching its peak concentration in the blood within 20 to 60 minutes. In healthy adults, about 50% of fluoride is eliminated by the kidneys, while in infants and young children, retention reaches up to 90%.

Fluoride that enters blood plasma is primarily distributed to the skeleton or excreted. However, it can also cross the placenta and accumulate in key areas of the developing brain, such as the cerebellum, motor cortex, and hippocampus .

Professor Philippe Grandjean of the University of Southern Denmark and co-author of the meta-analysis, warned that fluoride “is toxic to early brain development,” regardless of its source.

Recommendations to limit exposure to fluoride

Grandjean suggested reducing consumption of fluoridated products beyond drinking water, such as toothpaste and certain black teas grown in fluoride-rich soils common in regions of East Africa, China, and India.

On the other hand, Robert Kennedy Jr., U.S. Secretary of Health and Human Services, has questioned the need for fluoridation in public water, arguing that fluoride’s benefits are largely topical. “There’s no reason to keep fluoride in the water supply when we have products like toothpaste and mouthwash,” he told the AP.

Kennedy announced his intention to ask the Centers for Disease Control and Prevention (CDC) to review its recommendations on community fluoridation. He has also formed a working group of experts to analyze the issue and propose new policies.

Evolving legislation

Utah set a precedent by becoming the first state to ban the addition of fluoride to drinking water. Other states, such as South Carolina, Florida, and Ohio, have introduced similar initiatives to restrict the practice, reflecting growing skepticism about its safety and effectiveness.