Fluoride may negatively affect kidney and liver function in adolescents
NEW YORK, U.S.: According to researchers at Mount Sinai hospital, New York, fluoride in drinking water can have potential health side effects, such as renal system damage, liver damage, thyroid dysfunction, bone and tooth disease, and impaired protein metabolism. In a recent study, they examined the effect of fluoride levels in drinking water and blood on the kidney and liver health of adolescents participating in the National Health and Nutrition Examination Survey (NHANES), a group of studies that assess health and nutritional well-being in the U.S.
The findings showed that exposure to fluoride may contribute to complex changes in kidney and liver function among youth in the U.S., where 74% of public water systems add fluoride for dental health benefits. Fluoridated water is the main source of fluoride exposure in the U.S. The findings also suggest that adolescents with poorer kidney or liver function may absorb more fluoride into their bodies.
Fluoride exposure in animals and adults has been associated with kidney and liver toxicity, and this study examined potential effects of chronic low-level exposure among youth. This is important because a child’s body excretes only 45% of fluoride in urine via the kidneys, whereas an adult’s body clears it at a rate of 60%. Moreover, the kidneys accumulate more fluoride than any other organ in the body.
The study analyzed fluoride measured in blood samples of 1,983 adolescents and the fluoride content of the tap water in the homes of 1,742 adolescents. Although the tap water fluoride concentrations were generally low, there are several mechanisms by which even low levels of fluoride exposure may contribute to kidney or liver dysfunction.
“While the dental benefits of fluoride are widely established, recent concerns have been raised regarding the appropriateness of its widespread addition to drinking water or salt in North America,” said the study’s first author, Dr. Ashley J. Malin, a postdoctoral fellow in the Department of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai. “This study’s findings suggest that there may be potential kidney and liver health concerns to consider when evaluating fluoride use and appropriate levels in public health interventions. Prospective studies are needed to examine the impact of chronic low-level fluoride exposure on kidney and liver function in the U.S. population.”
This study’s findings, combined with previous studies of childhood exposure to higher fluoride levels, show that there is a dose-dependent relationship between fluoride and the indicators of kidney and liver function. The findings, if confirmed in other studies, could suggest that it may be important to consider children’s kidney and liver function in drafting public health guidelines and recommendations.
The study, titled “Fluoride exposure and kidney and liver function among adolescents in the United States: NHANES, 2013–2016,” was published online on Aug. 8, 2019, in Environment International, ahead of inclusion in an issue.