Even more concerning is the mounting evidence that ingesting fluoride, even in amounts below the threshold set by the Environmental Protection Agency (EPA), may be linked to a number of serious health effects, including lowered IQ, arthritis symptoms, weakened bones, and thyroid problems.
Anti-fluoride activists have been campaigning for years to have fluoridation guidelines re-evaluated. A case currently before a U.S. District Court in California aims to end the practice of fluoridating two-thirds of American water supplies.
Fluoridated Water May Not Significantly Reduce Cavities
It’s now widely accepted that fluoride’s protective benefits come from topical application, not ingestion. Numerous studies have shown the ineffectiveness of ingesting fluoride for preventing tooth decay, the only reason it’s added to our water supplies. Non-fluoridating countries in western Europe have seen the same decline in dental decay since the mid twentieth century as the United States, suggesting another explanation for reduced incidence of cavities, such as better dental care and widespread use of fluoride toothpaste.
Some experts estimate that fluoridated water may prevent at most one cavity per child. In a comparison of cavity rates in Canada’s province of Quebec, which largely doesn’t fluoridate, and Ontario, where three-quarters of the water is fluoridated, researchers found that Ontario kids had less than half a cavity fewer than their Quebec counterparts.
A comprehensive review conducted by the Cochrane Group found that the studies the CDC relies on for demonstrating the effectiveness of fluoride in preventing tooth decay mostly predate 1975 (and thus the common use of fluoride toothpaste) and have some design flaws that call their findings into question. Study authors conclude, “Though indeed in the decades before ubiquitous fluoride toothpaste, fluoridating water appears to have cut caries incidence, since fluoride is now understood to work better topically, water fluoridation seems unnecessary.”
A longitudinal study funded by the National Institutes of Health known as the Iowa Fluoride/Bone Development Study has followed 570 children from infancy to young adulthood to evaluate the effects of fluoridated water on dental decay and fluorosis as well as bone health. The study generally has found a 10-15% lower rate of cavity formation in children living in fluoridated areas versus non-fluoridated areas. Steven Levy, who directs the study, explains that because of the demographics of the cohort, the decrease in caries rates would likely be much higher in a population with higher risk factors. The study participants who have persisted tend to brush regularly with fluoride toothpaste and have consistent dental care. In populations without these advantages, Levy says, fluoridated water would likely have a far greater protective effect.
Questioning the Continued Use
One of the reasons fluoride has been presumed safe is the possibly flawed assumptions on which the EPA has based its guidelines. Crippling skeletal fluorosis, a condition causing pain and tenderness in the joints, is less likely at levels below 4 mg/l, so the EPA has used that level as its maximum allowed. The EPA set a second, non-enforceable limit of 2mg/l of fluoride to protect against dental fluorosis, a condition that weakens tooth enamel. While water utilities are not required to comply with the secondary standard, they are required to notify their customers when their drinking water exceeds this level.
Today more than half of all adolescents in the United States exhibit some signs of dental fluorosis. Research indicates that endocrine effects may occur at much lower levels than previously believed, and some experts think it prudent to assume that other health effects may also result from low-level exposure to fluoride. Canada and countries in the European Union set a permitted level at 1.5mg/l, which many feel is still too high.
In 2006 the National Research Council conducted a review of the EPA standard, and called for it to be lowered. Importantly, members of the review committee noted the need for further research on a number of fluoride’s possible health effects. As a 2014 review of extent research published in the Scientific World Journal concluded:
“…available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally.”
Late in 2016 a coalition of groups including Food and Water Watch, The American Academy of Environmental Medicine, Fluoride Action Network, International Academy of Oral Medicine and Toxicology, Moms against Fluoridation, and several private citizens filed a petition with the EPA calling for a ban on the addition of fluoridation chemicals to drinking water supplies. The EPA turned down the petition, claiming it did “not set forth a scientifically defensible basis to conclude that any persons have suffered neurotoxic harm as a result of exposure to fluoride in the U.S. through the purposeful addition of fluoridation chemicals to drinking water or otherwise from fluoride exposure in the U.S.”
The coalition has brought the complaint to the U.S District Court in Northern California for an independent de novo review. The court will be asked to assess whether fluoridation of water indeed presents an “unreasonable risk” and can compel the EPA to ban the addition of fluoride to public drinking water. Michael Connett, legal counsel for the plaintiffs, explains that “if the EPA applies its own risk assessment procedures to fluoride, it would recognize the potential for harm from fluoridated water.” Moreover, Connett points to “recent epidemiological data showing little or no difference [in caries incidence] in fluoridated vs. unfluoridated communities.” Though there have been some conflicting studies showing declines in rates of dental decay, Connett points out that “the magnitude of benefit” is small and needs to be weighed against the potential harm.
“…widely dispersing a neurotoxin throughout the environment can have devastating unintended consequences and warrants protective action sooner rather than later.”- Michael Connett
Connett likens the situation to leaded gasoline, which government entities also believed safe until they discovered otherwise. Connett warns that as we learned in the case of lead, “widely dispersing a neurotoxin throughout the environment can have devastating unintended consequences and warrants protective action sooner rather than later.” He expects the EPA to respond to the complaint in early fall and the court to hear arguments a few months later.
The complaint cites over 300 studies showing fluoride’s neurotoxic effects, some at doses not much higher than what many of us ingest in drinking water and prepared foods on a daily basis. As with lead, mercury, and arsenic, mounting science suggests that levels of ingested fluoride thought safe are not, and the precautionary principle dictates avoidance of a substance until it’s definitely proven safe.
One of the many issues in water fluoridation is the problem of uncontrolled dosage. People’s intake of water and foods prepared with fluoridated water varies widely, and with the prevalence of fluoridated water used in prepared foods, it’s possible to exceed the maximum daily intake. Further, people respond differently to drugs, and offering the same dose to everyone regardless of age, health status, or other factors is hardly standard medical practice. It’s important to note that fluoride is not a nutrient, but a substance added to our water to prevent disease, which makes it a drug. We have rights under the law to refuse medical treatment, but avoiding fluoride is extremely difficult. Even if we remove it from our drinking water—at our own expense—we can’t easily avoid it in purchased food.
Reducing Your Fluoride Exposure
If you want to limit the amount of fluoride you consume, the logical place to start is your tap. Most water filters don’t remove fluoride, so if you live in a municipality with naturally-occurring fluoride or one that fluoridates drinking water, choosing a filter designed to remove fluoride is your best defense. Note that fluoride exposure also comes from foods and drinks processed with fluoride, and until labeling laws require disclosure of fluoride, it’s best to assume that your soup, beverages, and other foods prepared with water will have a high probability of containing fluoride. Black and green tea also contain significant amounts of naturally-occurring fluoride, especially when they’re grown in regions with high fluoride levels.
As our understanding of fluoride’s health effects continues to grow, more of us are adopting the precautionary principle in our approach to ingesting it. Will the courts weigh the evidence and rule that community water fluoridation is no longer a public good but a public health risk? Only time will tell.
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