Background: Ingestion of fluoride in drinking water has been shown to result in increased cellular markers of inflammation in rodent models. However, the approximately 10x greater fluoride concentrations in drinking water required by rat and mouse models to obtain blood fluoride concentrations similar those of found in humans, has made the relevance of these animal studies difficult to assess. Increased white blood cell count is a marker of inflammation in humans, and therefore we used available 2013-2016 NHANES survey data, which includes both blood cell counts and plasma fluoride concentrations, to explore the relationship between fluoride and inflammation in humans.
OBJECTIVE: To assess associations between plasma fluoride levels and blood cell markers of inflammation in a US population.
METHODS: Multiple linear regressions to determine the association of blood cell counts and plasma fluoride were done using publicly available NHANES survey data from the 2013-2014 and 2015-2016 cycles. Plasma fluoride concentrations were available for children aged 6 to 19, and therefore this subpopulation was used for all analyses. Covariate predictors along with plasma fluoride were age, gender, and Body Mass Index (BMI).
RESULTS: Plasma fluoride was significantly positively associated with water fluoride, total white blood cell count, segmented neutrophils, monocytes, and negatively associated with red blood cell count when adjusted for age, gender and BMI.
CONCLUSION: Our finding that neutrophils and monocytes are associated with higher plasma fluoride in US children and adolescents is consistent with animal data showing fluoride related effects in increasing inflammation. These findings suggest the importance of further studies to assess potential mechanisms for these fluoride related effects in tissues and organs, such as the small intestine, liver and kidney, that are involved in absorption and filtration of ingested fluoride.