If you live in the US, there’s a good chance you’re almost one 209 million people Drinking fluoridated tap water. Local governments are adding fluoride to city water supplies About 80 years. In many ways, its addition has been a remarkable public health success: According to the Centers for Disease Control and Prevention (CDC), drinking fluoridated water Reduces tooth decay by 25 percent.
But in late August, the US National Toxicology Program (NTP) released a long-awaited Report states “with moderate confidence” that drinking water with higher fluoride levels is associated with lower IQ in children.
Our drinking water contains fluoride Inspired conspiracy theories For generations, Robert F. Kennedy Jr., a prominent anti-vaxxer and Covid-19 skeptic, has been one of vocal proponents Banning fluoridation to protect children from neurodevelopmental problems.
This is not a conspiracy theory though. Scientists have spent ages trying to find out What level of fluoride strikes the best balance between oral health and healthy brain development? New to NTP 324-page report By reviewing the results of more than 500 experiments, giving more weight to the idea that fluoride may be linked to brain problems than, say, a single fraud, Study now withdrawn Linking vaccines to autism.
Science is a frustratingly non-linear process. Facts that seemed unquestionable a decade ago can be overturned by new facts at any moment. If you’ve never thought about fluoride outside of the dentist’s office, hearing that it can have neurotoxic effects can be confusing, scary, or disturbing. So why do we still have fluoride in our water and toothpaste?
It’s not because dentists and scientists are lying to us (although sometimes they do). Because finding the whole, unwavering truth is a never-ending process.
So, don’t throw away your toothpaste and stock up on bottled water. Here’s what science says (and doesn’t say) about fluoride and the brain.
Why does the government want us to drink fluoride?
Fluoride is a mineral that occurs naturally in soil, water, and the things we consume brewed tea and shellfish. It is also in the toothpaste that most of us use. Fluoride Strengthens our enamel and prevents cavities. It’s more than just maintaining pearly white teeth; left untreated, Tooth decay Leads to serious infection, which can spread throughout the body.
At the beginning of the 20th century, dental researchers noticed that many people living near high fluoride water sources had stained teeth, a condition called fluorosis. Once the scientists started Studying the effect of fluoride on dental healthThey realized that, although high concentrations of fluoride can damage teeth and bones, drinking water with low levels of fluoride actually prevents tooth decay. Today, many cities add small amounts of fluoride to their tap water — about 0.7 milligrams per liter (mg/L).
But the United States is home to about 1.9 million people Tap water is naturally high in fluoride According to the report, than the recommendation of the government. For example, the Ogallala Aquiferwhich supplies water for West Texas, mixed with fluoride-rich volcanic ash Fluoride concentration up to 5 mg/L.
The report pegged fluoride levels at 1.5 mg/L – almost double the level Recommended by federal health officials – Children with low IQ. According to the NTP, more research is needed to find out if high levels of fluoride pose a risk to adults or the lower concentrations recommended by the government.
Although these results have been reproduced enough times to be taken seriously, the science of intelligence—including the concept of IQ—is questionable.
Measuring brain development is complicated
Measuring brain function is not easy. After all, the brain has many functions: keeping the body alive, helping us walk and talk, guiding us to learn and make decisions.
More than 70 of the 100 human studies reviewed by NTP looked specifically at children’s IQ as a proxy for brain development — IQ tests are easier and cheaper to conduct than brain scans or full neurological tests. Of those 72 IQ-related studies, only 19 were flagged by NTP as having low risk of bias, controlling for factors such as socioeconomic status, which may contribute For differences in IQ scores. Only a few of these 19 studies were conducted in North America and none in the United States.
So, critically, none of these human studies tell us anything about how fluoride changes the brain at a biological level. Even animal and cell studies in the lab have not identified how fluoride might affect learning, memory or intelligence.
IQ scores only capture an incomplete picture of early childhood brain development, and it’s tangled up in several. Socio-economic, ethnic, And cultural Factors outside of how much fluoride someone is exposed to.
Historically, Mothers were blamed for their children’s cognitive disabilities. Blaming environmental factors like the MMR vaccine — or, say, fluoridated water — can give parents a sense of control over a scary-sounding diagnosis. A 2017 Federal case The EPA is already calling for a ban on water fluoridation Enthusiastic support of high-profile anti-vaxxers.
The trial depends on the findings of the NTP’s final report, a draft of which was originally presented a year ago. There has been a protracted legal battle messyDental health advocates oppose fluoride research and Denying NTP results.
If the court decides that fluoride poses health risks that outweigh its benefits, it could end water fluoridation in the United States.
In the midst of scientific uncertainty and political shadiness, it’s hard to know what to believe.
Who should I trust? What should I do?
For now, the NTP has determined only “with moderate confidence” that there is an association between higher fluoride exposure and lower IQ in children — specifically, an IQ 2 to 5 points lower.
But it’s hard to know how we would measure differences in lived experience based on a few IQ points.
If you’re concerned about your household’s fluoride exposure, you can check your tap water’s fluoride levels at the CDC. My water fluoride page. If you live anywhere with levels above 1.5 mg/L, your tap water crosses the threshold of neurodevelopmental concern. No need to switch to bottled water though; Home water purifier can Completely filters out fluoride.
To make sure you don’t throw away the oral health benefits of fluoride with the bathwater, stick to fluoride toothpaste for them. Over 2 years old (Just don’t swallow it).
And if you’re still a fluoride-skeptic, you can order some hydroxyapatite toothpaste — which has similar cavity-preventing benefits — from Europe or Canada, where it is approved and approved by the Dental Association.
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