The cholinergic system, intelligence, and dental fluorosis in school-aged children with low-to-moderate fluoride exposure

Wang, Sumei; Zhao, Qian; Li, Gaochun; Wang, Mengwei; Liu, Hongliang; Yu, Xingchen; Chen, Jingwen; Li, Pei; Dong, Lanlan; Zhou, Guoyu; Wang, Mengru; Liu, Li; Wang, Aiguo

doi:10.1016/j.ecoenv.2021.112959

Cited by 17 publications

(10 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The negative finding for dental fluorosis and IQ was consistent with three previous studies [ 9 , 16 , 22 ] but was inconsistent with several studies of school-age children [ 8 , 12 , 21 , 23 , 24 , 25 , 26 , 27 ]. The non-significant association between urinary fluoride and IQ was consistent with three previous studies [ 20 , 21 , 22 ] but was conflicting with many other studies [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

Section: Discussionsupporting

confidence: 79%

“…Second, it was difficult to clarify the temporal relationship between the urinary fluoride measured and the current IQ scores in this cross-sectional study. Although the same study design was used in studies that reported a significant IQ-urinary fluoride association among schoolchildren [6][7][8][9][10][11][12][13][14][15][16][17][18][19], future investigations with a cohort study design may help to better understand the effects of early childhood fluoride exposure on intelligence. Third, about 41% of the schoolchildren who were invited to participate in this study completed the evaluation of dental fluorosis, the IQ test, and the measurement of urinary fluoride.…”

Section: Discussionmentioning

confidence: 99%

“…In the past 20 years, many studies have investigated the association of urinary fluoride levels and dental fluorosis with intelligence quotient (IQ) scores among school-age children, and the results were inconsistent. While the majority of the studies reported a significant reverse relationship between urinary fluoride concentrations and IQ [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ], three reviewed studies did not observe a significant association [ 20 , 21 , 22 ]. Furthermore, several studies reported that dental fluorosis was significantly associated with lower IQ among school-age children [ 8 , 12 , 21 , 23 , 24 , 25 , 26 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren

et al. 2023

View full text Add to dashboard Cite

Fluoride is present naturally in water and has been used worldwide for the prevention of caries. Several studies conducted in high water fluoride or endemic fluorosis areas reported that fluoride adversely affected children’s cognitive function, but some studies had negative findings. This study aimed to assess the relationship between urinary fluoride, dental fluorosis, and intelligence among schoolchildren living in communities with non-fluoridated drinking water. This cross-sectional study was conducted on 562 children aged 6–12 years in Taichung, Taiwan. Each child’s urinary fluoride level was determined by a fluoride-ion-selective electrode, and the dental fluorosis condition was evaluated according to the criteria of Dean’s Index. The Raven’s Colored Progressive Matrices-Parallel and Standard Progressive Matrices-Parallel were used to assess children’s intelligence. The results showed that the mean (±standard deviation) urinary fluoride concentrations were 0.40 ± 0.27 mg/L (0.43 ± 0.23 mg/g creatinine) among participants. The prevalence of dental fluorosis was 23.67%. After extensive evaluation of potential confounders, dental fluorosis and urinary fluoride were not associated with intelligence quotient (IQ) scores or grades in the regression models. In conclusion, dental fluorosis and urinary fluoride levels were not significantly related to the IQ of schoolchildren living in areas with low drinking water fluoride.

show abstract

Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The effect of fluorosis on intelligence may involve multiple different pathways, and the mechanisms of its effects are very complex. After it crosses the blood–brain barrier, fluoride can affect and change the cerebellum, hippocampus, and cerebral cortex to varying degrees, thereby affecting intellectual development ( 46 , 47 ). The ultrastructural pathological results indicated that fluoride exerted a significant damaging effect on the blood–brain barrier, mainly manifested as astrocyte foot edema, mitochondrial degeneration, and poor function of microvascular endothelial cells.…”

Section: Discussionmentioning

confidence: 99%

Exploration of the SIRT1-mediated BDNF–TrkB signaling pathway in the mechanism of brain damage and learning and memory effects of fluorosis

Wang,

Li,

Tang

et al. 2023

Front. Public Health

View full text Add to dashboard Cite

IntroductionFluoride is considered an environmental pollutant that seriously affects organisms and ecosystems, and its harmfulness is a perpetual public health concern. The toxic effects of fluoride include organelle damage, oxidative stress, cell cycle destruction, inflammatory factor secretion, apoptosis induction, and synaptic nerve transmission destruction. To reveal the mechanism of fluorosis-induced brain damage, we analyzed the molecular mechanism and learning and memory function of the SIRT1-mediated BDNF–TrkB signaling pathway cascade reaction in fluorosis-induced brain damage through in vivo experiments.MethodsThis study constructed rat models of drinking water fluorosis using 50 mg/L, 100 mg/L, and 150 mg/L fluoride, and observed the occurrence of dental fluorosis in the rats. Subsequently, we measured the fluoride content in rat blood, urine, and bones, and measured the rat learning and memory abilities. Furthermore, oxidative stress products, inflammatory factor levels, and acetylcholinesterase (AchE) and choline acetyltransferase (ChAT) activity were detected. The pathological structural changes to the rat bones and brain tissue were observed. The SIRT1, BDNF, TrkB, and apoptotic protein levels were determined using western blotting.ResultsAll rats in the fluoride exposure groups exhibited dental fluorosis; decreased learning and memory abilities; and higher urinary fluoride, bone fluoride, blood fluoride, oxidative stress product, and inflammatory factor levels compared to the control group. The fluoride-exposed rat brain tissue had abnormal AchE and ChAT activity, sparsely arranged hippocampal neurons, blurred cell boundaries, significantly fewer astrocytes, and swollen cells. Furthermore, the nucleoli were absent from the fluoride-exposed rat brain tissue, which also contained folded neuron membranes, deformed mitochondria, absent cristae, vacuole formation, and pyknotic and hyperchromatic chromatin. The fluoride exposure groups had lower SIRT1, BDNF, and TrkB protein levels and higher apoptotic protein levels than the control group, which were closely related to the fluoride dose. The findings demonstrated that excessive fluoride caused brain damage and affected learning and memory abilities.DiscussionCurrently, there is no effective treatment method for the tissue damage caused by fluorosis. Therefore, the effective method for preventing and treating fluorosis damage is to control fluoride intake.

show abstract

“…It is a normal component of bones and teeth, an essential element for the formation of enamel, and has an antiosteoporosis function. , However, fluorine, like other elements, is harmful to human health in both excess and deficiency and excessive content can cause poisoning. Fluorine has a strong affinity for calcium and phosphorus in the human body; it can disrupt the normal calcium and phosphorus metabolism as well as inhibit the activity of certain enzymes, resulting in dental fluorosis, skeletal fluorosis, kidney, liver, and brain damage, abnormal immune function, pulmonary edema, pulmonary hemorrhage, mental decline in children, and other diseases. − The World Health Organization (WHO) stipulates that the index value of F – in drinking water is 1.5 mg/L (∼63.16 μM) . The Chinese national standard requires the content of free and soluble fluoride in fluoride toothpaste to be greater than or equal to 400 mg/kg.…”

mentioning

confidence: 99%

Portable Smartphone Platform Based on Aggregation-Induced Enhanced Emission Carbon Dots for Ratiometric Quantitative Sensing of Fluoride Ions

et al. 2023

View full text Add to dashboard Cite

The development of an instrument-free, on-site, real-time, sensitive, and visualized fluoride-ion (F–) content rapid detection strategy is crucial to ensuring the health of the population. Smart microdevices that are portable, directly read, and easy to operate have recently attracted much attention. Herein, a ratiometric fluorescent probe (AA-CDs@[Ru(bpy)3]2+)-based smartphone sensing platform was developed for the detection of F–. The red fluorescent ruthenium bipyridine [Ru(bpy)3]2+ molecule was chosen as the reference signal, and the carbon dots (AA-CDs) with Al3+ aggregation-induced enhanced emission (AIE) were designed as the response signal. The ratiometric probe fluorescence changed continuously from red to cyan in response to different concentrations of F–, and the red–green–blue (RGB) channel values of the fluorescence image were extracted through the smartphone color recognition application (APP). There was a linear relationship between the blue–red (B/R) ratio and the F– concentration, with a limit of detection (LOD) of 1.53 μM, far below the allowable content of F– in drinking water prescribed by the World Health Organization. The F– content was rapidly detected on-site with satisfactory repeatability and relative standard deviation using several water and toothpaste samples as the real sample. The platform features low cost, portability, easy operation, and good stability, selectivity, and repeatability, which provides a powerful tool for the visual quantitative detection of smartphone-based microsensing platforms possibly in the fields of environmental protection, diagnosis, and food safety assessment.

show abstract

The cholinergic system, intelligence, and dental fluorosis in school-aged children with low-to-moderate fluoride exposure

Cited by 17 publications

References 59 publications

Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren

Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren

Exploration of the SIRT1-mediated BDNF–TrkB signaling pathway in the mechanism of brain damage and learning and memory effects of fluorosis

Portable Smartphone Platform Based on Aggregation-Induced Enhanced Emission Carbon Dots for Ratiometric Quantitative Sensing of Fluoride Ions

Contact Info

Product

Resources

About