January, 2024: The LOTUS Study – With 6.4 million study subjects, this is the largest fluoride study ever conducted. Its aim was to determine the effectiveness and cost-effectiveness of water fluoridation for adults and adolescents. Over 10 years, people receiving optimally fluoridated water experienced only a 2% reduction in the number of decayed, missing, and filled teeth, compared to those whose water was not fluoridated. The study found NO meaningful benefit to water fluoridation, nor any compelling evidence that water fluoridation reduced social inequalities in dental health.  [WATCH VIDEO - 1:37 minutes]

January 2024: Fluoride exposure and thyroid hormone levels in pregnancy – This is the first study to investigate sex differences in the association between fluoride exposure and maternal thyroid hormone levels in pregnancy. It found that 1 mg/L increase in urinary fluoride was associated with a 35% increase in thyroid stimulating hormone (TSH) among women pregnant with girls. Urinary fluoride concentration is an objective biomarker of short-term fluoride exposure. It allows for more precise estimates of fluoride intake from multiple sources.

*The MIREC Study, which started in 2007, is an ongoing study to examine the effects of prenatal exposure to environmental chemicals on the health of pregnant women and their infants. 

November 2023: Systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water – This Canadian study identifies both dental fluorosis and reduction in children's IQ scores as key endpoints for establishing a health-based value (HBV) for fluoride in drinking water. The authors state that neurodevelopmental cognitive effects may warrant special consideration in determining HBV. They suggest a “point of departure” of 1.56 mg/L for fluoride in drinking water for establishing a reference dose and public health safety guidelines, based only on the lowest-observed-adverse-effect level (LOAEL) for moderate and severe dental fluorosis. They do not address the potential impact on IQ scores.

September, 2023 – A study by University of Calgary researchers found “poorer inhibitory control and cognitive flexibility” in preschool children whose mothers were pregnant during times when the water was fluoridated in Calgary, Canada. The authors said their tests measured “executive function deficits [that have been] consistently associated with behavioural and neurodevelopmental disorders such as ADHD, autism spectrum disorder (ASD), intellectual disability, and specific learning disorders”. Executive dysfunction disrupts the ability to manage thoughts, emotions, and actions, including the ability to pay attention, solve problems, listen, and multitask.

Till et al., February 2023 – Professor Christine Till and PhD student Meaghan Hall found an association between fluoride exposure from tap water and hypothyroidism in pregnancy. They say this latest study may explain an earlier study looking at maternal fluoride exposure in pregnancy and lower IQ in boys.  “The findings are concerning because hypothyroidism is a known cause of brain-based disorders in children,” says Till. Hall and Till say they hope that policy makers will consider this new research when evaluating the safety of community water fluoridation.

Well-designed prospective cohort studies funded by both the National Institute of Environmental Health Sciences [NIEHS] in the USA as well as Health Canada, have shown a loss of IQ and increased symptoms of ADHD in offspring when pregnant women are exposed to fluoride at doses commonly experienced in fluoridated communities in Canada (Bashash, 2017, 2018 and Green, 2019).  The consequences are shocking!  According to Dr. Philippe Grandjean, from Harvard University, “Fluoride is causing a greater overall loss of IQ points today than lead, arsenic or mercury”, as detailed in this risk analysis.

Till et al., 2020 have shown a large reduction in IQ when children were bottle-fed as babies in communities which were fluoridated, compared with babies who were bottle-fed in non-fluoridated communities.

According to Linda Birnbaum, Ph.D., former Director of the U.S. NIEHS (2009-2019) and two leading public health researchers (Bruce Lanphear, MD, MPH, and Christine Till, PhD) who authored two key fluoride-IQ studies (Green, 2019 and Till, 2020), ingestion of fluoride during pregnancy confers no dental benefit to the fetus, so this is a situation where risks are being taken for no proven benefit (see their editorial published in Environmental Health News, Oct 7 2020).

An important well-conducted study from Sweden has shown an increased prevalence of hip fracture in post-menopausal women associated with long term exposure to natural fluoride at levels in water in the same range as Canada fluoridates its water [Helte et. al., 2021].  This is very serious because, as you probably know, hip fractures in the elderly are debilitating, costly to treat, lead to a loss of independence and often shortens the life of those impacted.  This finding also underlines the fact that fluoride can impact our health over a whole lifetime of exposure.