New HRB report reviews health effects of community water fluoridation

Review finds no definitive evidence that community water fluoridation has negative health effects.

Picture of water flowing from a tap

The Health Research Board (HRB) has published an in-depth evidence review of existing research in relation to the health effects of community water fluoridation. 

Dr Mairead O’Driscoll, HRB Chief Executive, says: “Having examined the research available, the HRB continues to find no definitive evidence that community water fluoridation is associated with negative health effects. With new studies emerging all the time, these reviews conducted by the HRB at regular intervals can help equip policy makers with the most up-to-date evidence base to inform decisions in relation to water fluoridation.”

Community water fluoridation is a public health practice that was introduced to improve dental health by reducing the incidence of tooth decay. Ireland fluoridates its water to 0.7 parts per million (ppm), well within the World Health Organization (WHO) guideline level of 1.5 ppm. The HRB provides an overview of scientific evidence on potential benefits and risks of fluoridation at regular intervals for the Department of Health.

According to Dr Kathryn Lambe, lead author of the report and Research Officer at the HRB: “Our review examined findings from 30 studies in 9 countries, including Ireland. We found no evidence for a link between fluoride and most conditions we examined, including bone health, cancer, kidney stones, birth and infant abnormalities, and death rates.

“The findings on bone health and cancer are of interest. These conditions were flagged as areas for further monitoring in our review in 2015. This updated review has found no definitive evidence that fluoridation of water was linked to bone health and cancer."

Two areas require further monitoring: thyroid conditions and neuropsychological outcomes. The existing research in these areas is limited, with generally mixed and inconsistent findings, and is unable to provide conclusive evidence of a link between fluoridated water and these outcomes. New high-quality longitudinal studies – which track the same individuals over time – are needed. The HRB will continue to monitor the research in this area going forward.

The current review focuses on systemic (whole-body) health, with a HRB review focusing on dental health to be published next year.

The report in full is available to download from the HRB website


For further information or to organise interviews with experts, please contact:

Anna Dunne, Communications Officer, Health Research Board 
m +353 85 859 0339  e


The Health Research Board (HRB) is Ireland’s lead funding agency supporting innovative health research and delivering data and evidence that improves people’s health and patient care. We are committed to putting people first, and ensuring data and evidence are used in policy and practice to overcome health challenges, advance health systems, and benefit society and economy.