New Fluoride Study Ignores Neurotoxicity and Sugar Intake in Cost Analysis

A new fluoride study has been criticized for being a tool of the industry to promote continued water fluoridation following the banning of the practice in Utah and Florida. The authors conducted a simulation model and cost-effectiveness analysis with data from 8484 children with a mean age of 9.6 years. The authors concluded eliminating fluoride from the water supply would cost $9.8 billion over 5 years due to increased dental caries.

The study did not account for notable confounding factors, including sugar consumption. The study did not evaluate the neurotoxic effects of fluoride, as revealed in the National Toxicology Program (NTP) report published last year, which led to the groundbreaking court victory against the EPA. In this case, the judge ruled that community water fluoridation poses an “unreasonable risk” to public health.

Dr. Lisa Simon obtained the funding and also has a lengthy conflict of interest disclosure in the study. The disclosure states, “Dr. Simon personal fees from Boston Medical Center, Alosa Health, the American College of Legal Medicine, the American Dental Therapy Association, the California Dental Association, the Santa Fe Group, the Society of Teachers of Family Medicine, the American College of Dentists, the CareQuest Foundation for Oral Health, and the American Dental Association, all outside the submitted work. No other disclosures were reported.”

The HighWire has reported about the conflict of interest the American Dental Association (ADA) has with the promotion of fluoride. It has a “seal of approval” program in which dental hygiene companies pay money to obtain the ADA seal for fluoride toothpaste and mouthwash products.

The authors wrote, “These effects would disproportionately affect publicly insured and uninsured children, who are already at highest risk of unmet dental needs.” The authors add, “Children with reduced access to dental care, such as those from families who are publicly insured, have low income, or live in rural areas, derive the most benefit.”

The authors of the study assume a 25% reduction in dental caries as a result of community water fluoridation to drive the microsimulation model that concludes billions of dollars in costs if water fluoridation is halted nationwide. The 25% reduction is based on the Cochrane Review, which has been criticized for primarily using studies from before 1975.

Stephen Peckham, Director of the Centre for Health Services Studies (CHSS) at the University of Kent, wrote a letter criticizing the evidence that shows water fluoridation reduces dental caries, including the Cochrane Review. He wrote, “Comprehensive and systematic reviews of water fluoridation do not support these claims, and where such claims have been made they are based on inconclusive evidence and predominantly studies carried out pre 1975 – before the wide use of fluoride toothpaste (See limitations noted in the 2015 Cochrane Review and earlier 2000 NHSCRD review).”  

The HighWire has referred to the top 10 list of countries with the fewest amount of dental caries in previous reports. This list shows that the United States, the most fluoridated country in the world, is ninth. 66% of the US population lives in a jurisdiction with community water fluoridation. The UK has a fluoridation rate of 11%, while Canada has a rate of 38%. The rest of the top 10 list of countries do not add fluoride to their drinking water. Denmark is number one with 0.4 compared to 1.2 for the US, which represents the number of teeth out of 20 that are either decayed, missing, or filled.

A study published in January 2025 analyzed the impact of sugar consumption on Decayed, Missing, and Filled Teeth (DMFT) outcomes. The authors wrote, “Children in the highest quartiles of sugar consumption consistently exhibited elevated DMFT scores across three NHANES data cycles (2011–2016). Additionally, significant disparities in caries prevalence were observed, with children from low-income households, Mexican American children, and those with less-educated parents exhibiting higher caries rates.”

This study analyzed outcomes from the same time period as the latest fluoride study, but Choi and Simon did not adjust for this confounding factor in their analysis.

Fluoride is a naturally occurring mineral that is also an industrial byproduct of mining and fertilizer operations. The Fluoride Action Network, the group behind the victorious 7-year lawsuit against the EPA, wrote that the “vast majority” of fluoride used in US municipal water systems comes from China. China does not add fluoride to community water systems.

The study’s authors wrote “Because there is no consensus on the neurocognitive effects of fluoride at the levels used in PWS and current federal guidance does not find an association between PWS fluoridation and neurocognitive decline, we did not include this outcome in the model.”

The NTP report released last year found that water fluoridation levels of 1.5 mg per liter are associated with lower IQ in children. This is the recommended level by the World Health Organization, but more than twice the recommended amount of 0.7 mg in the US. However, the EPA’s actionable levels are 4.0 mg, and approximately 0.6% of the US population resides in jurisdictions with water fluoridation at 1.5 mg or higher. That equates to 1.9 million people.

The Fluoride Action Network reported that 78 out of 87 studies from 1989 to 2023 found “elevated fluoride is associated with reduced IQ in humans.”

Attorney Michael Connett, who represented FAN in the court case against the EPA, stated on The HighWire that there is no systemic benefit from fluoride. This means that consuming fluoride has no benefits, but it is associated with neurotoxic effects and lower IQ in humans. Fluoride in toothpaste and mouthwash can provide the public with topical fluoride benefits without exposing people to the neurotoxic effects associated with fluoride consumption via fluoridated tap water.