The presence of fluoride in water aids in preventing certain cavities, yet apprehensions about potential health hazards spark debates over the benefits versus drawbacks.
A recent study by the Cochrane Collaboration, a group that examines scientific research without bias, suggests a minor advantage to adding fluoride to tap water, resulting in fewer cavities in children's primary teeth. Previous research from before 1975 indicated more significant benefits, with children from fluoridated areas having approximately one fewer tooth affected by decay than those from non-fluoridated areas.
However, the authors of this new report argue that these findings are not applicable to modern populations due to wider access to various sources of fluoride and lower rates of dental disease at the outset. The widespread use of fluoride toothpaste since the 1970s has likely played a role in this shift.
More recent studies have linked fluoride in water to a decrease in decay by an average of about a quarter of a tooth, according to the report published this week.
The study concludes that adding fluoride to water might slightly increase the number of children with no decay in their primary or permanent teeth, but it also acknowledges the possibility of no difference in decay rates.
Recent concerns about fluoride's impact on young children's cognitive development have led a federal judge to order the US Environmental Protection Agency to tighten regulations on fluoride in drinking water.
Understanding Fluoride
Fluoride is a mineral found naturally in certain foods and water sources. It strengthens the enamel of teeth by protecting them from acids produced by bacteria, plaque, and sugars in the mouth. The practice of adding fluoride to public water systems began in the United States in 1945.
More than 209 million Americans receive water from fluoridated systems, according to data from the US Centers for Disease Control and Prevention. The CDC advocates for the safety and benefits of community water fluoridation, which it cites as the most cost-effective method of delivering fluoride to the entire population.
However, recent research may be altering the perceived risks and benefits of this long-standing public health intervention.
The new Cochrane report, which calls into question the scale of the advantages of adding fluoride to water, follows other reports that heighten concerns about the risks.
Balancing Benefits and Risks
A study published in JAMA Network Open in May linked exposure to fluoridated water during pregnancy to increased neurobehavioral issues in children. A review by the National Institutes of Health's toxicology program published in August concluded that higher levels of fluoride are associated with lower IQ in children.
Despite the absence of definitive evidence that typical water fluoride levels cause lower IQ in children, US District Judge Edward Chen ruled in a case against the EPA that this warrants further investigation.
The EPA establishes limits and recommendations for fluoride levels under the Safe Drinking Water Act. The agency is currently reviewing Chen's decision and considering its next steps in coordination with the Department of Justice.
The findings of the new Cochrane report do not provide a clear mandate for adding fluoride to drinking water, experts say.
According to Dr. Howard Hu, a professor of preventive medicine at the University of Southern California's Keck School of Medicine and founding director of the NIH/NIEHS Center for Children's Environmental Health, it is becoming challenging to determine if and to what extent there are significant benefits to maintaining water fluoridation programs in current times, particularly considering readily available alternatives for preventing tooth decay and the risks associated with fluoride exposure.
The risks include dental fluorosis, a condition that causes minor discolorations on teeth, and accumulating evidence of neurodevelopmental toxicity from prenatal fluoride exposure, Hu said. He co-authored a study on prenatal exposure to fluoride.
Some major health organizations, such as the American Academy of Pediatrics and American Dental Association, continue to support the use of fluoride as a safe and effective means of maintaining oral health.
The American Academy of Pediatrics addressed the limitations of the National Institutes of Health review and emphasized the long-term consequences of tooth decay and cavities, a common and preventable chronic disease.
“While more research to better understand the association and potential mechanisms would be beneficial, there is nothing about the research that makes me concerned (about) the low levels of fluoride through toothpaste and drinking fluoridated water,” Dr. Charlotte W. Lewis, a professor of pediatrics at the University of Washington School of Medicine and attending physician at Seattle Children's Hospital, said in a statement.
The new Cochrane report raises questions about the substantial benefits of adding fluoride to water due to wider access to various fluoride sources and lower dental disease rates, potentially challenging the long-standing public health intervention. However, organizations like the American Academy of Pediatrics and American Dental Association continue to support fluoride as a safe and effective method for maintaining oral health, acknowledging the long-term consequences of tooth decay.
