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Zhang Y, Gao Y, Liu X. Focus on cognitive impairment induced by excessive fluoride: An update review. Neuroscience 2024; 558:22-29. [PMID: 39137871 DOI: 10.1016/j.neuroscience.2024.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 08/06/2024] [Accepted: 08/07/2024] [Indexed: 08/15/2024]
Abstract
Fluorosis is a global public health concern. Prolonged exposure to excessive fluoride causes fluoride accumulation in the hippocampus, resulting in cognitive dysfunction. Cell death is necessary for maintaining tissue function and morphology, and changes in the external morphology of nerve cells and the function of many internal organelles are typical features of cell death; however, it is also a typical feature of cognitive impairment caused by fluorosis. However, the pathogenesis of cognitive impairment caused by different degrees of fluoride exposure varies. Herein, we provide an overview of cognitive impairment caused by excessive fluoride exposure in different age groups, and the underlying mechanisms for cognitive impairment in various model organisms. The mechanisms underlying these impairments include oxidative stress, synaptic and neurotransmission dysfunction, disruption of mitochondrial and energy metabolism, and calcium channel dysregulation. This study aims to provide potential insights that serve as a reference for subsequent research on the cognitive function caused by excessive fluoride.
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Affiliation(s)
- Yuhang Zhang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province 150081, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, Heilongjiang 150081, China; Heilongjiang Provincial Key Lab of Trace Elements and Human Health, Harbin, Heilongjiang 150081, China
| | - Yanhui Gao
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province 150081, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, Heilongjiang 150081, China; Heilongjiang Provincial Key Lab of Trace Elements and Human Health, Harbin, Heilongjiang 150081, China.
| | - Xiaona Liu
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province 150081, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health (23618504), Harbin, Heilongjiang 150081, China; Heilongjiang Provincial Key Lab of Trace Elements and Human Health, Harbin, Heilongjiang 150081, China.
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Farmus L, Till C, Green R, Hornung R, Martinez-Mier EA, Ayotte P, Muckle G, Lanphear B, Flora D. Critical windows of fluoride neurotoxicity in Canadian children by Farmus and colleagues - In reply to Wood et al. (2023). ENVIRONMENTAL RESEARCH 2024; 254:115299. [PMID: 36709876 DOI: 10.1016/j.envres.2023.115299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Linda Farmus
- Department of Psychology, York University, Toronto, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Canada
| | - Richard Hornung
- Consultant to Psychology Department, York University, Toronto, ON, Canada
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada
| | - Gina Muckle
- Centre de Recherche Du CHU de Québec, Université Laval, Québec City, QC, Canada; School of Psychology, Université Laval, Québec, QC, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
| | - David Flora
- Department of Psychology, York University, Toronto, Canada
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Wang R, Gong W, Jiang Y, Yin Q, Wang Z, Wu J, Zhang M, Li M, Liu Y, Wang J, Chen Y, Ji Y. Fluoride exposure during puberty induces testicular impairment via ER stress-triggered apoptosis in mice. Food Chem Toxicol 2024; 189:114773. [PMID: 38823497 DOI: 10.1016/j.fct.2024.114773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 05/15/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024]
Abstract
Fluoride, a ubiquitous environmental compound, carries significant health risks at excessive levels. This study investigated the reproductive toxicity of fluoride exposure during puberty in mice, focusing on its impact on testicular development, spermatogenesis, and underlying mechanisms. The results showed that fluoride exposure during puberty impaired testicular structure, induced germ cell apoptosis, and reduced sperm counts in mice. Additionally, the SOD activity and GSH content were significantly decreased, while MDA content was significantly elevated in the NaF group. Immunohistochemistry showed an increase in the number of cells positive for GRP78, a key ER stress marker. Moreover, qRT-PCR and Western blot analyses confirmed the upregulation of both Grp78 mRNA and protein expression, as well as increased mRNA expression of other ER stress-associated genes (Grp94, chop, Atf6, Atf4, and Xbp1) and enhanced protein expression of phosphorylated PERK, IRE1α, eIF2α, JNK, XBP-1, ATF-6α, ATF-4, and CHOP. In conclusion, our findings demonstrate that fluoride exposure during puberty impairs testicular structure, induces germ cell apoptosis, and reduces sperm counts in mice. ER stress may participate in testicular cell apoptosis, and contribute to the testicular damage and decreased sperm counts induced by fluoride.
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Affiliation(s)
- Rong Wang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China; School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Wenjing Gong
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Yumeng Jiang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Qizi Yin
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Ziyue Wang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Jie Wu
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Mingming Zhang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Mengyuan Li
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Yehao Liu
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Juan Wang
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
| | - Yuanhua Chen
- School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China.
| | - Yanli Ji
- Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Anhui Provincial Key Laboratory of Population Health and Aristogenics, Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei Anhui, China.
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Xu P, Xing H, Ma Y, Ding X, Li T, Zhang Y, Liu L, Ma J, Niu Q. Fluoride Induces Neurocytotoxicity by Disrupting Lysosomal Iron Metabolism and Membrane Permeability. Biol Trace Elem Res 2024:10.1007/s12011-024-04226-0. [PMID: 38760610 DOI: 10.1007/s12011-024-04226-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/06/2024] [Indexed: 05/19/2024]
Abstract
The detrimental effects of fluoride on neurotoxicity have been widely recorded, yet the detailed mechanisms underlying these effects remain unclear. This study explores lysosomal iron metabolism in fluoride-related neurotoxicity, with a focus on the Steap3/TRPML1 axis. Utilizing sodium fluoride (NaF)-treated human neuroblastoma (SH-SY5Y) and mouse hippocampal neuron (HT22) cell lines, our research demonstrates that NaF enhances the accumulation of ferrous ions (Fe2+) in these cells, disrupting lysosomal iron metabolism through the Steap3/TRPML1 axis. Notably, NaF exposure upregulated ACSL4 and downregulated GPX4, accompanied by reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity and increased malondialdehyde (MDA) levels. These changes indicate increased vulnerability to ferroptosis within neuronal cells. The iron chelator deferoxamine (DFO) mitigates this disruption. DFO binds to lysosomal Fe2+ and inhibits the Steap3/TRPML1 axis, restoring normal lysosomal iron metabolism, preventing lysosomal membrane permeabilization (LMP), and reducing neuronal cell ferroptosis. Our findings suggest that interference in lysosomal iron metabolism may mitigate fluoride-induced neurotoxicity, underscoring the critical role of the Steap3/TRPML1 axis in this pathological process.
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Affiliation(s)
- Panpan Xu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Hengrui Xing
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Yue Ma
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Xueman Ding
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Tingting Li
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Yue Zhang
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Li Liu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China
| | - Jiaolong Ma
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China.
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China.
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China.
| | - Qiang Niu
- Department of Preventive Medicine, School of Medicine, Shihezi University, North 2nd Road, Shihezi, Xinjiang, 832000, People's Republic of China.
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, the Xinjiang Production and Construction Corps, Shihezi, Xinjiang, People's Republic of China.
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases (Ministry of Education), School of Medicine, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
- NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence DiseasesFirst Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China.
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Malin AJ, Eckel SP, Hu H, Martinez-Mier EA, Hernandez-Castro I, Yang T, Farzan SF, Habre R, Breton CV, Bastain TM. Maternal Urinary Fluoride and Child Neurobehavior at Age 36 Months. JAMA Netw Open 2024; 7:e2411987. [PMID: 38767917 PMCID: PMC11107298 DOI: 10.1001/jamanetworkopen.2024.11987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/18/2024] [Indexed: 05/22/2024] Open
Abstract
Importance Recent studies in Canadian and Mexican populations suggest an association of higher prenatal fluoride exposure with poorer neurobehavioral development, but whether this association holds for US-based populations is unknown. Objective To examine associations of third trimester maternal urinary fluoride (MUF) with child neurobehavior at age 3 years in the US. Design, Setting, and Participants This prospective cohort study utilized urine samples archived from 2017 to 2020 and neurobehavioral data assessed from 2020 to 2023 from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) pregnancy cohort, which consisted of predominately Hispanic women residing in Los Angeles, California. Cohort eligibility criteria at recruitment included being 18 years of age or older, less than 30 weeks' gestation, and a fluent English or Spanish speaker. Exclusion criteria included having a disability preventing participation or provision of informed consent, being HIV positive or incarcerated, and having a multiple gestation pregnancy. There were 263 mother-child pairs who completed the 3-year study visit. In this analysis, women who reported prenatal smoking were excluded. Data analysis was conducted from October 2022 to March 2024. Exposure Specific gravity-adjusted MUF (MUFSG), a biomarker of prenatal fluoride exposure. Main Outcomes and Measures Neurobehavior was quantified using the Preschool Child Behavior Checklist (CBCL), which included composite scores for Total Problems, Internalizing Problems, and Externalizing Problems. CBCL composite T scores range from 28 to 100. T scores from 60 to 63 are in the borderline clinical range, whereas scores above 63 are in the clinical range. Linear and logistic regression models adjusted for covariates were conducted. Results A total of 229 mother-child pairs (mean [SD] maternal age, 29.45 [5.67] years; 116 female children [50.7%] and 113 male children [49.3%]) who had MUFSG measured were included in the study. Median (IQR) MUFSG was 0.76 (0.51-1.19) mg/L, and 32 participants (14.0%) had a Total Problems T score in the borderline clinical or clinical range. A 1-IQR (0.68 mg/L) increase in MUFSG was associated with nearly double the odds of the Total Problems T score being in the borderline clinical or clinical range (odds ratio, 1.83; 95% CI, 1.17-2.86; P = .008), as well as with a 2.29-point increase in T score for the Internalizing Problems composite (B = 2.29; 95% CI, 0.47-4.11; P = .01) and a 2.14-point increase in T score for the Total Problems composite (B = 2.14; 95% CI, 0.29-3.98; P = .02). Conclusions and Relevance In this prospective cohort study of mother-child pairs in Los Angeles, California, prenatal fluoride exposure was associated with increased neurobehavioral problems. These findings suggest that there may be a need to establish recommendations for limiting fluoride exposure during the prenatal period.
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Affiliation(s)
- Ashley J. Malin
- Department of Epidemiology, College of Public Health and Health Professions University of Florida, Gainesville
- College of Medicine, University of Florida, Gainesville
| | - Sandrah P. Eckel
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - E. Angeles Martinez-Mier
- Department of Dental Public Health and Dental Informatics, School of Dentistry, Indiana University, Indianapolis
| | - Ixel Hernandez-Castro
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Tingyu Yang
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Shohreh F. Farzan
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Rima Habre
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Carrie V. Breton
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Theresa M. Bastain
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles
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Tang H, Hou H, Song L, Tian Z, Liu W, Xia T, Wang A. The role of mTORC1/TFEB axis mediated lysosomal biogenesis and autophagy impairment in fluoride neurotoxicity and the intervention effects of resveratrol. JOURNAL OF HAZARDOUS MATERIALS 2024; 467:133634. [PMID: 38335616 DOI: 10.1016/j.jhazmat.2024.133634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/16/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024]
Abstract
Elevated exposures to fluoride have been linked to neurological diseases. Identifying mechanisms of fluoride neurotoxicity and finding ways for prevention and treatment of epidemic fluorosis are important issues of public health. In this study, fluoride inhibited TFEB nuclear translocation by activating p-mTORC1/p-p70S6K, thus inhibiting lysosomal biogenesis, leading to dysfunctional lysosome accumulation, which further negatively affected autophagosome and lysosome fusion, thus impairing autophagy degradation, evidenced by the blocked conversion of LC3II to LC3I, and the increased p62 levels. Interestingly, RSV alleviated rats' cognition by improving fluoride-induced nerve damage and promoted lysosomal biogenesis demonstrated by the increased nucleus translocation of TFEB via inhibiting p-mTORC1 and p-p70S6K, the decreased expression of LC3II and p62. Collectively, we clarified the correlation between fluoride neurotoxicity and mTORC1/TFEB-mediated lysosomal biogenesis and autophagy. Meanwhile, RSV appeared to be a promising drug for the prevention and treatment of epidemic fluorosis.
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Affiliation(s)
- Huayang Tang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Haoqi Hou
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Li Song
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Zhiyuan Tian
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Wenhui Liu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Tao Xia
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
| | - Aiguo Wang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
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Grandjean P, Meddis A, Nielsen F, Beck IH, Bilenberg N, Goodman CV, Hu H, Till C, Budtz-Jørgensen E. Dose dependence of prenatal fluoride exposure associations with cognitive performance at school age in three prospective studies. Eur J Public Health 2024; 34:143-149. [PMID: 37798092 PMCID: PMC10843960 DOI: 10.1093/eurpub/ckad170] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Fluoride may be a developmental neurotoxicant at elevated exposures. We merged new data from a prospective Odense Child Cohort (OCC) with results from two previous birth cohort studies from Mexico and Canada to characterize the dose-effect relationship in greater detail. METHODS The OCC contributed 837 mother-child pairs to the total of >1500. We measured creatinine-adjusted urine-fluoride concentrations in maternal urine samples obtained during late pregnancy. Child IQ was determined at age 7 years using an abbreviated version of the Wechsler Intelligence Scales for Children. Findings from the three cohorts were used to calculate the joint benchmark concentration (BMC) and the lower confidence limit (BMCL) after adjustment for covariables. RESULTS In the OCC, urine-fluoride concentrations varied between 0.08 and 3.04 mg/l (median 0.52 mg/l) but were not significantly associated with full-scale IQ at age 7 years (β = 0.08; 95% confidence interval -1.14 to 1.30 for a doubling in exposure). No difference was apparent between boys and girls. In the OCC, the BMC was 0.92 mg/l, with a BMCL of 0.30 mg/l. The joint analysis of all three cohorts showed a statistically significant association between urine-fluoride and IQ, with a BMC of 0.45 mg/l (BMCL, 0.28 mg/l), slightly higher than the BMC previously reported for the two North American cohorts alone. CONCLUSIONS As the BMCL reflects an approximate threshold for developmental neurotoxicity, the results suggest that pregnant women and children may need protection against fluoride toxicity.
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Affiliation(s)
- Philippe Grandjean
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Flemming Nielsen
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
| | - Iben H Beck
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
| | - Niels Bilenberg
- Department of Child and Adolescent Psychiatry, Odense University Hospital, Odense, Denmark
| | - Carly V Goodman
- Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Christine Till
- Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada
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Taher MK, Momoli F, Go J, Hagiwara S, Ramoju S, Hu X, Jensen N, Terrell R, Hemmerich A, Krewski D. Systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water. Crit Rev Toxicol 2024; 54:2-34. [PMID: 38318766 DOI: 10.1080/10408444.2023.2295338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 11/27/2023] [Indexed: 02/07/2024]
Abstract
INTRODUCTION Fluoride is a naturally occurring substance that is also added to drinking water, dental hygiene products, and food supplements for preventing dental caries. Concerns have been raised about several other potential health risks of fluoride. OBJECTIVE To conduct a robust synthesis of evidence regarding human health risks due to exposure to fluoride in drinking water, and to develop a point of departure (POD) for setting a health-based value (HBV) for fluoride in drinking water. METHODS A systematic review of evidence published since recent reviews of human, animal, and in vitro data was carried out. Bradford Hill considerations were used to weigh the evidence for causality. Several key studies were considered for deriving PODs. RESULTS The current review identified 89 human studies, 199 animal studies, and 10 major in vitro reviews. The weight of evidence on 39 health endpoints was presented. In addition to dental fluorosis, evidence was considered strong for reduction in IQ scores in children, moderate for thyroid dysfunction, weak for kidney dysfunction, and limited for sex hormone disruptions. CONCLUSION The current review identified moderate dental fluorosis and reduction in IQ scores in children as the most relevant endpoints for establishing an HBV for fluoride in drinking water. PODs were derived for these two endpoints, although there is still some uncertainty in the causal weight of evidence for causality for reducing IQ scores in children and considerable uncertainty in the derivation of its POD. Given our evaluation of the overall weight of evidence, moderate dental fluorosis is suggested as the key endpoint until more evidence is accumulated on possible reduction of IQ scores effects. A POD of 1.56 mg fluoride/L for moderate dental fluorosis may be preferred as a starting point for setting an HBV for fluoride in drinking water to protect against moderate and severe dental fluorosis. Although outside the scope of the current review, precautionary concerns for potential neurodevelopmental cognitive effects may warrant special consideration in the derivation of the HBV for fluoride in drinking water.
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Affiliation(s)
- Mohamed Kadry Taher
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
| | - Franco Momoli
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Jennifer Go
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Shintaro Hagiwara
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Siva Ramoju
- Risk Sciences International, Ottawa, ON, Canada
| | - Xuefeng Hu
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Natalie Jensen
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Rowan Terrell
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
| | - Alex Hemmerich
- Risk Sciences International, Ottawa, ON, Canada
- Faculty of Education, Queen's University, Kingston, ON, Canada
| | - Daniel Krewski
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
- Risk Sciences International, Ottawa, ON, Canada
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9
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Zhu X, Zhang S, Liu X, Li H, Zhu X, Zhang J, Wang X, Zhang M. Integrative transcriptome and metabolome analysis of fluoride exposure induced developmental neurotoxicity in mouse brain. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 269:115752. [PMID: 38039848 DOI: 10.1016/j.ecoenv.2023.115752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 11/19/2023] [Accepted: 11/25/2023] [Indexed: 12/03/2023]
Abstract
Fluoride could cause developmental neurotoxicity and significantly affect the intelligence quotient (IQ) of children. However, the systematic mechanism of neuronal damage caused by excessive fluoride administration in offspring is largely unknown. Here, we present a comprehensive integrative transcriptome and metabolome analysis to study the mechanism of developmental neurotoxicity caused by chronic fluoride exposure. Comparing the different doses of fluoride treatments in two generations revealed the exclusive signature of metabolism pathways and gene expression profiles. In particular, neuronal development and synaptic ion transport are significantly altered at the gene expression and metabolite accumulation levels for both generations, which could act as messengers and enhancers of fluoride-induced systemic neuronal injury. Choline and arachidonic acid metabolism, which highlighted in the integrative analysis, exhibited different regulatory patterns between the two generations, particularly for synaptic vesicle formation and inflammatory factor transport. It may suggest that choline and arachidonic acid metabolism play important roles in developmental neurotoxic responses for offspring mice. Our study provides comprehensive insights into the metabolomic and transcriptomic regulation of fluoride stress responses in the mechanistic explanation of fluoride-induced developmental neurotoxicity.
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Affiliation(s)
- Xinliang Zhu
- College of Life Science, Northwest Normal University, Lanzhou 730070, Gansu Province, China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China; Institute of Rural Development and Research, Northwest Normal University, Lanzhou 730070, Gansu Province, China.
| | - Shunbin Zhang
- College of Life Science, Northwest Normal University, Lanzhou 730070, Gansu Province, China
| | - Xiaoxiao Liu
- Lanzhou Institute of Food and Drug Control, Lanzhou 740050, China
| | - Huixia Li
- Gansu Tongxing Intelligent Technology Development Co., Ltd., Lanzhou 730070, Gansu Province, China
| | - Xinyu Zhu
- Department of General Surgery, Gansu Provincial Hospital, Lanzhou 730000, China
| | - Ji Zhang
- College of Life Science, Northwest Normal University, Lanzhou 730070, Gansu Province, China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China; Institute of Rural Development and Research, Northwest Normal University, Lanzhou 730070, Gansu Province, China
| | - Xiaopeng Wang
- Department of General Surgery, Gansu Provincial Hospital, Lanzhou 730000, China
| | - Min Zhang
- Department of Scientific Research, Gansu Provincial Hospital, Lanzhou 730000, China; Department of General Surgery, Gansu Provincial Hospital, Lanzhou 730000, China.
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10
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Godebo TR, Jeuland M, Tekle-Haimanot R, Alemayehu B, Shankar A, Wolfe A, Phan N. Association between fluoride exposure in drinking water and cognitive deficits in children: A pilot study. Neurotoxicol Teratol 2023; 100:107293. [PMID: 37690675 DOI: 10.1016/j.ntt.2023.107293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/12/2023]
Abstract
Fluoride (F) exposure in drinking water may lead to reduced cognitive function among children; however, findings largely remain inconclusive. In this pilot study, we examined associations between a range of chronic F exposures (low to high: 0.4 to 15.5 mg/L) in drinking water and cognition in school-aged children (5-14 years, n = 74) in rural Ethiopia. Fluoride exposure was determined from samples of community-based drinking water wells and urine. Cognitive performance was measured using: 1) assessments of ability to draw familiar objects (donkey, house, and person), and 2) a validated Cambridge Neuropsychological Test Automated Battery's (CANTAB) Paired Associate Learning (PAL), which examines memory and new learning and is closely associated with hippocampus function of the brain. Associations between F and cognitive outcomes were evaluated using regression analysis, adjusting for demographic, health status, and other covariates. The median (range) of water and urine F levels was 7.6 (0.4-15.5 mg/L) and 6.3 (0.5-15.7 mg/L), respectively; these measures were strongly correlated (r = 0.74), indicating that water is the primary source of F exposure. Fluoride in drinking water was negatively associated with cognitive function, measured by both drawing and CANTAB test performance. Inverse relationships were also found between F and drawing objects task scores, after adjusting for covariates (p < 0.05). Further analysis using CANTAB PAL tasks in the children confirmed that F level in drinking water was positively associated with the number of errors made by children (p < 0.01), also after adjusting for covariates (p < 0.05). This association between water F and total errors made became markedly stronger as PAL task difficulty increased. Fluoride exposure was also inversely associated with other PAL tasksthe number of patterns reached, first attempt memory score and mean errors to success. These findings provide supportive evidence that high F exposures may be associated with cognitive deficits in children. Additional well-designed studies are critically needed to establish the neurotoxicity of F in children and adults exposed to both low levels known to protect dental caries, as well as excess F levels in drinking water.
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Affiliation(s)
- Tewodros Rango Godebo
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.
| | - Marc Jeuland
- Sanford School of Public Policy and Duke Global Health Institute, Duke University, Durham, NC, 27708, USA
| | - Redda Tekle-Haimanot
- Addis Ababa University, School of Medicine, Department of Neurology, Addis Ababa, Ethiopia
| | - Biniyam Alemayehu
- Addis Ababa University, School of Medicine, Department of Neurology, Addis Ababa, Ethiopia
| | - Arti Shankar
- Department of Biostatistics and Data Science, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Amy Wolfe
- University of Kentucky, Kentucky Geological Survey, Lexington, KY, 40506, USA
| | - Nati Phan
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
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11
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Malin AJ, Hu H, Martínez-Mier EA, Eckel SP, Farzan SF, Howe CG, Funk W, Meeker JD, Habre R, Bastain TM, Breton CV. Urinary fluoride levels and metal co-exposures among pregnant women in Los Angeles, California. Environ Health 2023; 22:74. [PMID: 37880740 PMCID: PMC10601173 DOI: 10.1186/s12940-023-01026-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/13/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND Fluoride is ubiquitous in the United States (US); however, data on biomarkers and patterns of fluoride exposure among US pregnant women are scarce. We examined specific gravity adjusted maternal urinary fluoride (MUFsg) in relation to sociodemographic variables and metal co-exposures among pregnant women in Los Angeles, California. METHODS Participants were from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort. There were 293 and 490 women with MUFsg measured during first and third trimesters, respectively. An intra-class correlation coefficient examined consistency of MUFsg between trimesters. Kruskal-Wallis and Mann-Whitney U tests examined associations of MUFsg with sociodemographic variables. Covariate adjusted linear regression examined associations of MUFsg with blood metals and specific gravity adjusted urine metals among a subsample of participants within and between trimesters. A False Discovery Rate (FDR) correction accounted for multiple comparisons. RESULTS Median (IQR) MUFsg was 0.65 (0.5) mg/L and 0.8 (0.59) mg/L, during trimesters one and three respectively. During both trimesters, MUFsg was higher among older participants, those with higher income, and White, non-Hispanic participants than Hispanic participants. MUFsg was also higher for White, non-Hispanic participants than for Black, non-Hispanic participants in trimester three, and for those with graduate training in trimester one. MUFsg was negatively associated with blood mercury in trimester one and positively associated with blood lead in trimester three. MUFsg was positively associated with various urinary metals, including antimony, barium, cadmium, cobalt, copper, lead, nickel, tin, and zinc in trimesters one and/or three. CONCLUSIONS MUFsg levels observed were comparable to those found in pregnant women in Mexico and Canada that have been associated with poorer neurodevelopmental outcomes. Lower urinary fluoride levels among Hispanic and non-Hispanic Black participants in MADRES compared to non-Hispanic White participants may reflect lower tap water consumption or lower fluoride exposure from other sources. Additional research is needed to examine whether MUFsg levels observed among pregnant women in the US are associated with neurodevelopmental outcomes.
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Affiliation(s)
- Ashley J Malin
- Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, University of Florida, 2004 Mowry Rd, Gainesville, 32603, USA.
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - E Angeles Martínez-Mier
- Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry, Indiana University, 1121 W. Michigan St., Indianapolis, IN, 46202-2876, USA
| | - Sandrah P Eckel
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Shohreh F Farzan
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Caitlin G Howe
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, 1 Medical Center Drive, Williamson Translational Research Building, 7th Floor, Lebanon, NH, 03756, USA
| | - William Funk
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, 680 N Lake Shore Dr Ste 1400, Chicago, IL, 60611, USA
| | - John D Meeker
- Department of Environmental Health Sciences, University of Michigan School of Public Health, 1420 Washington Hts, Ann Arbor, MI, 48109, USA
| | - Rima Habre
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Theresa M Bastain
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
| | - Carrie V Breton
- Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, 1845 N Soto Street, Los Angeles, CA, 90089-9239, USA
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12
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Lin YY, Hsu WY, Yen CE, Hu SW. Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren. CHILDREN (BASEL, SWITZERLAND) 2023; 10:987. [PMID: 37371219 DOI: 10.3390/children10060987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023]
Abstract
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.
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Affiliation(s)
- Yuh-Yih Lin
- Institute of Oral Sciences, Chung Shan Medical University, Taichung 40201, Taiwan
| | - Wen-Yu Hsu
- Department of Psychology, Chung Shan Medical University, Taichung 40201, Taiwan
| | - Chin-En Yen
- Department of Early Childhood Development and Education, Chaoyang University of Technology, Taichung 41349, Taiwan
| | - Suh-Woan Hu
- Institute of Oral Sciences, Chung Shan Medical University, Taichung 40201, Taiwan
- Department of Dentistry, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
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13
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Veneri F, Vinceti M, Generali L, Giannone ME, Mazzoleni E, Birnbaum LS, Consolo U, Filippini T. Fluoride exposure and cognitive neurodevelopment: Systematic review and dose-response meta-analysis. ENVIRONMENTAL RESEARCH 2023; 221:115239. [PMID: 36639015 DOI: 10.1016/j.envres.2023.115239] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Many uncertainties still surround the possible harmful effect of fluoride exposure on cognitive neurodevelopment in children. The aim of this systematic review and meta-analysis was to characterize this relation through a dose-response approach, by comparing the intelligence quotient (IQ) scores in the highest versus the lowest fluoride exposure category with a random-effects model, within a one-stage dose-response meta-analysis based on a cubic spline random-effects model. Out of 1996 potentially relevant literature records, 33 studies were eligible for this review, 30 of which were also suitable for meta-analysis. The summary mean difference of IQ score, comparing highest versus lowest fluoride categories and considering all types of exposure, was -4.68 (95% confidence interval-CI -6.45; -2.92), with a value of -5.60 (95% CI -7.76; -3.44) for drinking water fluoride and -3.84 (95% CI -7.93; 0.24) for urinary fluoride. Dose-response analysis showed a substantially linear IQ decrease for increasing water fluoride above 1 mg/L, with -3.05 (95% CI -4.06; -2.04) IQ points per 1 mg/L up to 2 mg/L, becoming steeper above such level. A weaker and substantially linear decrease of -2.15 (95% CI -4.48; 0.18) IQ points with increasing urinary fluoride emerged above 0.28 mg/L (approximately reflecting a water fluoride content of 0.7 mg/L). The inverse association between fluoride exposure and IQ was particularly strong in the studies at high risk of bias, while no adverse effect emerged in the only study judged at low risk of bias. Overall, most studies suggested an adverse effect of fluoride exposure on children's IQ, starting at low levels of exposure. However, a major role of residual confounding could not be ruled out, thus indicating the need of additional prospective studies at low risk of bias to conclusively assess the relation between fluoride exposure and cognitive neurodevelopment.
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Affiliation(s)
- Federica Veneri
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), Unit of Dentistry & Oral-Maxillo-Facial Surgery - University of Modena and Reggio Emilia, Modena, Italy; PhD Program in Clinical and Experimental Medicine, Department of Biomedical, Metabolic and Neural Sciences - University of Modena and Reggio Emilia, Modena, Italy
| | - Marco Vinceti
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy; Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.
| | - Luigi Generali
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), Unit of Dentistry & Oral-Maxillo-Facial Surgery - University of Modena and Reggio Emilia, Modena, Italy
| | - Maria Edvige Giannone
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy
| | - Elena Mazzoleni
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy
| | - Linda S Birnbaum
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Ugo Consolo
- Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), Unit of Dentistry & Oral-Maxillo-Facial Surgery - University of Modena and Reggio Emilia, Modena, Italy
| | - Tommaso Filippini
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Biomedical, Metabolic and Neural Sciences, Medical School - University of Modena and Reggio Emilia, Modena, Italy; School of Public Health, University of California Berkeley, Berkeley, CA, USA
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14
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A Scoping Review of Iodine and Fluoride in Pregnancy in Relation to Maternal Thyroid Function and Offspring Neurodevelopment. Adv Nutr 2023; 14:317-338. [PMID: 36796438 DOI: 10.1016/j.advnut.2023.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 02/04/2023] Open
Abstract
Iodine (I), an essential nutrient, is important for thyroid function and therefore growth and development. Fluoride (F), also an essential nutrient, strengthens bones and teeth, and prevents childhood dental caries. Both severe and mild-to-moderate I deficiency and high F exposure during development are associated to decreased intelligence quotient with recent reports associating high levels of F exposure during pregnancy and infancy to low intelligence quotient. Both F and I are halogens, and it has been suggested that F may interfere with the role of I in thyroid function. We provide a scoping review of the literature on I and F exposure dur pregnancy and their individual effects on thyroid function and offspring neurodevelopment. We first discuss I intake and status in pregnancy and the relationship to thyroid function and offspring neurodevelopment. We follow with the F in pregnancy and offspring neurodevelopment. We then review the interaction between I and F on thyroid function. We searched for, and found only one study that assessed both I and F in pregnancy. We conclude more studies are needed.
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