A reader recently asked me:
“If Europe doesn’t fluoridate its water, why do they still have lower cavity rates than the U.S.?”
It’s a thoughtful question—and the answer has become national news.
In September 2024, a U.S. federal court ruled that the chemicals used to fluoridate public water supplies pose an unreasonable risk to human health, especially to the developing brains of children.
The Ruling That Changed Everything
In a landmark decision, Judge Edward Chen of the U.S. District Court for the Northern District of California determined in Food & Water Watch et al. v. EPA that water fluoridation violates the Toxic Substances Control Act (TSCA) because of scientifically supported risks of neurodevelopmental harm.
This is the first time a federal court has concluded that adding fluoride to public water is not merely ineffective but is unsafe under federal chemical safety law.
“The Court concludes that plaintiffs have carried their burden and proven by a preponderance of the evidence that fluoridation presents an unreasonable risk of neurodevelopmental harm.”
—Judge Edward Chen
The plaintiffs presented more than 100 peer-reviewed studies arguing that fluoride exposure—particularly during pregnancy—can impair cognitive development in children. One influential study cited at trial was a 2019 NIH-funded paper in JAMA Pediatrics that linked higher maternal fluoride exposure with lower IQ scores in boys.
Cochrane Review: Limited Benefit, Measurable Risk
The most rigorous review to date, published by the Cochrane Collaboration in 2015, found that modern evidence supporting water fluoridation is weak:
- Of 155 studies reviewed, only three met modern scientific standards.
- The average observed benefit was about 0.3 fewer decayed teeth per child in fluoridated areas.
- At the same time, the risk of dental fluorosis was consistently higher across populations.
When the net benefit is so small and the risks are measurable, continuing a policy that exposes entire populations to a chemical deserves careful reconsideration.
Topical vs. Systemic Fluoride: A Key Distinction
An important difference is often missed in public debate:
- Topical fluoride (for example, toothpaste) works on the tooth surface.
- Systemic fluoride (for example, fluoridated drinking water) is ingested, absorbed into the bloodstream, and distributed throughout the body, including the brain.
Most cavity prevention benefits come from topical use, while most documented risks come from ingestion.
Fluoride and Neurotoxicity
In 2014, The Lancet Neurology published a review by toxicologists including Philippe Grandjean and Philip Landrigan identifying fluoride as a potential developmental neurotoxicant, based on evidence linking higher fluoride exposure to reduced cognitive outcomes in children. The authors urged use of the precautionary principle in public policy—protecting vulnerable populations before absolute proof is established.
Does Fluoride Actually Prevent Cavities?
Tooth decay is not caused by a fluoride deficiency. Primary drivers of dental decay include:
- An imbalanced oral microbiome
- Frequent sugar, acids, and refined carbohydrates
- Mouth breathing
- Low saliva flow
Swallowing fluoride in tap water does not address these root causes. Many European countries do not fluoridate their water yet report equal or lower rates of tooth decay than the U.S., largely thanks to public health systems that emphasize education, hygiene, and targeted topical fluoride use rather than systemic exposure.
Practical Alternatives and Priorities
If your goal is meaningful cavity prevention, focus on strategies that address causes and protect health:
- Use topical remineralizing products that restore enamel without systemic exposure.
- Support nutrition with adequate magnesium, vitamins K2 and D, and other minerals important for oral and overall health.
- Filter water with reverse osmosis if you want to reduce fluoride intake; standard filters usually won’t remove fluoride.
- Tackle root causes: reduce sugar intake, encourage nasal breathing, improve sleep, and support saliva flow.
- Protect the oral microbiome: avoid overuse of antiseptic mouthwashes, use a tongue scraper, and favor a low-sugar, whole-food diet that supports beneficial oral bacteria.
These approaches focus on preventing decay by addressing underlying issues rather than relying on systemic chemical exposure.
Final Thoughts
If fluoride were evaluated today as a new drug—with limited benefit and evidence of developmental risk—it likely would not meet approval standards. It’s time to reassess long-standing practices in light of current science and legal findings.
History and habit do not equal credibility. Real credibility comes from results, openness to new evidence, and a willingness to change when better information becomes available.
Please share this with your dentist, doctor, or local officials if you think it’s relevant—let the evidence and the recent ruling inform the conversation.
—Mark
