Fluoride exposure and sleep patterns among older adolescents in the United States: a cross-sectional study of NHANES 2015–2016

Abstract

BackgroundFluoride from environmental sources accumulates preferentially in the pineal gland which produces melatonin, the hormone that regulates the sleep-wake cycle. However, the effects of fluoride on sleep regulation remain unknown. This population-based study examined whether chronic low-level fluoride exposure is associated with sleep patterns and daytime sleepiness among older adolescents in the United States (US).MethodThis cross-sectional study utilized data from the National Health and Nutrition Examination Survey (2015–2016). We analyzed data from adolescents who had plasma fluoride (n = 473) and water fluoride (n = 419) measures and were not prescribed medication for sleep disorders. Relationships between fluoride exposure and self-reported sleep patterns or daytime sleepiness were examined using survey-weighted linear, binomial logistic or multinomial logistic regression after covariate adjustment. A Holm-Bonferroni correction accounted for multiple comparisons.ResultsThe average age of adolescents was 17 years (range = 16–19). Median (IQR) water and plasma fluoride concentrations were 0.27 (0.52) mg/L and 0.29 (0.19) μmol/L respectively. An IQR increase in water fluoride was associated with 1.97 times higher odds of reporting symptoms suggestive of sleep apnea (95% CI: 1.27, 3.05; p = 0.02), a 24 min later bedtime (B = 0.40, 95% CI: 0.10, 0.70; p = 0.05), a 26 min later morning wake time (B = 0.43, 95% CI: 0.13, 0.73; p = 0.04), and among males, a 38% reduction in the odds of reporting snoring (95% CI: 0.45, 0.87, p = 0.03).ConclusionsFluoride exposure may contribute to changes in sleep cycle regulation and sleep behaviors among older adolescents in the US. Additional prospective studies are warranted to examine the effects of fluoride on sleep patterns and determine critical windows of vulnerability for potential effects.

Fluoride exposure and duration and quality of sleep in a Canadian population-based sample

“…Given fluoride’s propensity to accumulate in the pineal gland [ 10 , 12 ], along with the well-established relationships of the degree of pineal gland calcification with human melatonin levels [ 16 – 18 ] and disruption to various sleep-related outcomes (including REM sleep percentage, total sleep time, sleep efficiency, daytime tiredness, and sleep disturbance) [ 18 , 19 ], further research is needed examining the potential for fluoride to impact sleep outcomes. To date, only one study has investigated the association between fluoride exposure and sleep [ 20 ]; none have examined this association in adult humans.…”

Mechanisms of Fluoride Toxicity: From Enzymes to Underlying Integrative Networks

“…The study of fluoride exposure and sleep patterns among a sample of adolescents living in the USA shows that fluoride exposure may be a risk factor for sleep disturbances [130]. The authors found that each 0.52 mg/L increase in tap water fluoride concentration was associated with 1.97 times higher odds of participants reporting snorting, gasping, or stopping breathing while sleeping at night.…”

Fluoride and Pineal Gland

“…Assuming the preferential accumulation of fluoride in the pineal gland and the related possible risk of toxic effects, Malin et al [11] have recently published a study on the processes of sleep regulation among older adults in the United States. They tried to answer the question of whether chronic exposure to low doses of fluoride has an effect on sleep patterns and daytime sleepiness in the studied population.…”

“…Additionally, adolescents who lived in areas with higher fluoride levels in tap water experienced more frequent daytime sleepiness. The authors [11] were of the opinion that fluoride exposure may contribute to increased pineal gland calcification and subsequent decreases in nighttime melatonin production that contribute to sleep disturbances.…”

“…One of the defense mechanisms protecting the body against the effects of fluoride toxicity seems to be its deposition in calcified tissues [2]. The most important role is played by hard tissues; bones; and teeth [2,[8][9][10], in which fluoride accumulates in the form of fluorohydroxylapatite and fluoroapatite, replacing hydroxyl ions in the hydroxylapatite structure [11,12]. These processes may occur at any point in life, starting as early as in the prenatal period [13][14][15], and their effects are observed even in the skeletons and dentition of archaeological excavations from the times when exposure to fluorine compounds was incomparably lower to modern times [16][17][18].…”