Review Shows Inverse Link Between Fluoride Exposure and Children”s IQ

MONDAY, Jan. 6, 2025 (HealthDay News) — Inverse associations are observed between fluoride measurements in urine and drinking water and children”s IQ, according to a review published online Jan. 6 in JAMA Pediatrics, although these findings are challenged in an accompanying editorial.

Kyla W. Taylor, Ph.D., from the National Institutes of Health in Research Triangle Park, North Carolina, and colleagues conducted a systematic review and meta-analysis of epidemiological studies examining children”s IQ scores and prenatal or postnatal fluoride exposure. Seventy-four studies were included: 64 cross-sectional and 10 cohort studies. Fifty-two of the studies were rated as having a high risk for bias and 22 were rated as having a low risk for bias.

The researchers found that inverse associations between fluoride exposure measures and children”s IQ were reported in 64 studies. An inverse association between fluoride exposure and IQ was seen in an analysis of 59 studies with group-level measures of fluoride in drinking water, dental fluorosis, or other measures of fluoride exposure. A dose-response association was seen between exposed and reference groups in 31 studies reporting fluoride measured in drinking water. The association remained inverse when exposed groups were restricted to <4 mg/L and <2 mg/L and was null at <1.5 mg/L. An inverse dose-response association was seen in 20 studies reporting fluoride measured in urine.

“Despite the presentation of some evidence of a possible association between IQ and high fluoride levels in water, there is no evidence of an adverse effect at the lower water fluoride levels commonly used in community water fluoridation systems,” Steven M. Levy, D.D.S., M.P.H., from the University of Iowa in Iowa City, writes in an accompanying editorial. “Therefore, public policy concerning the addition of fluoride to community water systems and recommendations concerning the use of topical fluoride in its many forms should not be affected by the study findings.”

Abstract/Full Text

Editorial 1 (subscription or payment may be required)

Editorial 2 (subscription or payment may be required)