Does fluoride in drinking water hurt your brain?

(AP)

Back in 2011, the EPA reversed course and lowered the recommended maximum amount of fluoride in drinking water due to data that the levels then being allowed put kids at risk of dental fluorosis--streaking and pitting of teeth due to excessive fluoride, which also puts tooth enamel at risk.

This conclusion was a discordant note amidst all the accolades fluoride had won, starting with the discovery during the 1940s that people who lived near water supplies containing naturally occurring fluoride had fewer cavities in their teeth.   A massive push ensued, with government and industry encouraging cities and towns to add fluoride to water supplies.

Related: Dental health linked to dementia risk

Now, questions about the impact of fluoride on mental health are growing and can no longer be ignored.

A recently published Harvard study showed that children living in areas with highly fluoridated water have "significantly lower" IQ scores than those living in areas where the water has low fluoride levels.  In fact, the study analyzed the results of 27 prior investigations and found the following, among other conclusions:

* Fluoride may be a developmental neurotoxicant that affects brain development (in children) at exposures much below those that cause toxicity in adults.

* Rats exposed to (relatively low) fluoride concentrations in water showed cellular changes in the brain and increased levels of aluminum in brain tissue.

Other research studies in animals link fluoride intake to the development of beta-amyloid plaques (the classic finding in the brains of patients with Alzheimer's dementia).

And research on fluoride also has implicated it in changing the structure of the brains of fetuses, negatively impacting the behavioral/neurological assessment scores of newborns and, in animal studies, impairing memory.

This information is very important, from a psychiatric standpoint, because we have witnessed rising rates of attention deficit disorder, major depression, dementia and many other psychiatric illnesses since the 1940s, and because the United States (which fluoridates a much higher percentage of its drinking water than most countries, including European nations) has some of the highest rates of mental disorders in the world--by a wide margin.

It is not clear, of course, that fluoride is responsible wholly, or even in small measure, for these facts, but the connection is an intriguing one, especially in light of the new Harvard study.

Given the available data, I would recommend that children with learning disorders, attention deficit disorder, depression, attention-deficit disorder or other psychiatric illnesses refrain from drinking fluoridated water, and consult a dentist about the most effective way of delivering sufficient fluoride to the teeth directly, while minimizing absorption by the body as a whole--and the brain, specifically.