Fluoride, the Developing Brain, & the Case Against Fluoridated Water

Thanks to a fluoride shortage in the US right now, some public water systems have been reducing or suspending fluoridation. While some Americans might be wondering what this might mean for their teeth, we can’t help but wonder: Is less fluoride really such a bad thing?

After all, fluoride isn’t an essential nutrient. The body has no known biological need for it. Besides, drinking water is just one of many avenues of exposure. Add them together — toothpaste and other dental products, food and drink, certain medications, environmental sources — and the amount that any one person takes in each day can vary considerably.

Moreover, according to a 2024 Cochrane review, the dental benefits of fluoridated water now appear to be more modest than in decades past. At the same time, concerns about fluoride reach far beyond the teeth. As the IAOMT summarized in its position paper on the matter,

Scientific research has shown that fluoride exposure impacts the bones and teeth, as well as the cardiovascular, central nervous, digestive, endocrine, immune, integumentary, renal, and respiratory systems. It has been linked to Alzheimer’s disease, cancer, diabetes, heart disease, infertility, osteoarthritis, neurocognitive and neurobehavioral deficits, and many other adverse health outcomes.

Another concern is that fluoride interacts synergistically with other elements, including titanium, arsenic, and iodine to cause even greater negative health effects. Allergies to fluoride, nutrient deficiencies, genetic factors, and other variables also interact with, and amplify the impact of fluoride.

One concern that’s drawn particular attention in recent years is fluoride’s potential effect on the brain prenatally through early childhood. A number of studies have reported links between fluoride exposure and various measures of cognitive or neurodevelopmental function.

A systematic review published earlier this year in Genetics and Molecular Biology brought together a great deal of that research, along with lab and animal studies that could help researchers understand not only whether there may be a link but what could be happening biologically.

This systematic review suggests that fluoride exposure induces neurotoxic effects through interconnected mechanisms, including oxidative stress, mitochondrial dysfunction, apoptosis, and impaired autophagy. These cellular and molecular alterations are frequently associated with disrupted neuronal structure, synaptic dysfunction, and deficits in cognitive performance and neurodevelopment.

There’s a lot packed into those two sentences, so let’s break it down a bit.

Oxidative stress happens when the body produces more highly reactive molecules than its antioxidant defenses can readily handle. Too much can damage proteins, cell membranes, and even DNA. Mitochondrial dysfunction means interference with the tiny structures inside our cells that produce most of the energy those cells need to function.

Apoptosis is programmed cell death — normally an important and carefully controlled process — while autophagy is part of the cellular housekeeping system that breaks down and recycles damaged or unnecessary components. The research reviewed in this paper suggests that fluoride can interfere with these processes, too.

Why does any of this matter to the brain?

Neurons — a/k/a brain cells — need a lot of energy. They depend on healthy cellular machinery to develop, communicate, and maintain connections between them. Disrupt those processes, and the effects can potentially reach all the way from individual cells to learning, memory, and other aspects of cognitive function.

Now think about that kind of disruption happening while a brain is still developing.

What makes the current study so interesting is how evidence from different kinds of research starts to fit together. Population studies report neurodevelopmental links. Animal studies show changes in learning, memory, and brain tissue. Here, the experimental research included in the current review offers possible biological explanations for such effects.

And that brings us back to water fluoridation.

No study like this can tell us that every person with early exposure to fluoride through drinking water will experience neurological harm. Nor does it give us a point where exposure becomes harmful for even most people.

But that’s not necessarily the main question.

If fluoride were essential to human health, or if fluoridating drinking water produced enormous dental benefits that couldn’t be achieved in any other way, maybe that would outweigh the potential risks.

But, as noted, fluoride isn’t essential, and modern studies point toward better, biocompatible ways of protecting the teeth. The question we should be asking is whether the purported dental benefits of fluoridating everyone’s drinking water are really great enough to justify the potential risks, especially to children.

From the perspective of holistic, biological dentistry, the answer would be no.