Research: IQ Reduction
A certain low dose of fluoride intake may play a potential protective rather than harmful role in cognitive functions; however, high fluoride exposure is a potential risk factor for cognitive impairment.
Mang Li 1 & Yanhui Gao1 & Jing Cui1 & Yuanyuan Li 1 & Bingyun Li 1 & Yang Liu1 &
Jing Sun1 & Xiaona Liu1 & Hongxu Liu1 & Lijun Zhao1 & Dianjun Sun
Biol Trace Elem Res (2016) 172:53–60
Read Full Abstract
Fluoridation of the drinking water is a public policy whose aim is to improve dental health. Although the evidence is clear that fluoride is good for dental health, concerns have been raised regarding potential negative effects on cognitive develop- ment. We study the effects of fluoride exposure through the drinking water in early life on cognitive and non-cognitive ability, education and labor market outcomes in a large-scale setting. We use a rich Swedish register dataset for the cohorts born 1985-1992, together with drinking water fluoride data. To estimate the effect we exploit intra-municipality variation of fluoride, stemming from an exogenous varia- tion in the bedrock. First, we investigate and confirm the long-established positive relationship between fluoride and dental health. Second, we find precisely estimated zero effects on cognitive ability, non-cognitive ability and education. We do not find any evidence that fluoride levels below 1.5 mg/l have negative effects. Third, we find evidence that fluoride improves labor market outcome later in life, which confirms that good dental health is a positive factor on the labor market.
–The Effects of Fluoride In The Drinking Water
Linuz Aggeborn† Mattias O ̈hman
June 27, 2016
Overall, this investigation found no evidence of a detectable adverse outcome on offspring neurobehavioral development associated with maternal fluoride exposure during pregnancy. Fluoride measured in pregnancy urine and plasma was not significantly associated with child’s MDI at any age, and it did not differentially affect MDI at ages 1, 2, and 3. Furthermore, trimester-specific measures of maternal fluoride measures were not significantly associated with offspring MDI.
Fluoride exposure during pregnancy and its effects on childhood neurobehavior: a study among mother-child pairs from Mexico City, Mexico
Deena B. Thomas
A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Environmental Health Sciences) in the University of Michigan 2014
No significant differences in IQ because of fluoride exposure were noted. These findings held after adjusting for potential confounding variables, including sex, socioeconomic status, breastfeeding, and birth weight (as well as educational attainment for adult IQ outcomes).
These findings do not support the assertion that fluoride in the context of CWF programs is neurotoxic. Associations between very high fluoride exposure and low IQ reported in previous studies may have been affected by confounding, particularly by urban or rural status.
Community Water Fluoridation and Intelligence: Prospective Study in New Zealand
Jonathan M. Broadbent, PhD, W. Murray Thomson, BSc, PhD, Sandhya Ramrakha, PhD, Terrie E. Moffitt, PhD, Jiaxu Zeng, PhD, Lyndie A. Foster Page, BSc, PhD, and Richie Poulton, PhD
(Am J Public Health. Published
online ahead of print May 15, 2014: e1–e5. doi:10.2105/AJPH.2013.301857)