The Health Research Board published a review of existing research yesterday, in which it stated that more delving is needed to provide “definitive” confirmation.
Campaigners against artificially fluoridated water claim it is damaging people’s health.
HRB chief executive Graham Love said the study found no evidence that community water fluoridation was associated with positive or negative systemic health effects. “Given the lack of peer-reviewed research and the inappropriate design of many studies to detect a causal relationship, further research would be required to provide definitive proof,” Dr Love said.
The Department of Health asked the HRB to determine the impact on people’s health from having fluoridated water between 0.4 and 1.5 parts per million.
Water in Ireland is fluoridated at between 0.6 and 0.8 parts per million — half the limit allowed by the World Health Organisation.
Since fluoridation was introduced in 1964, numerous studies have shown a clear link between fluoridation and improved oral health.
However, the HRB was not asked by the department to include dental health in its review.
The HRB review presents evidence from two international studies — the York Review (2000) and the Australian Review (2007). It also reviewed research published in internationally peer- reviewed papers on fluoride and health effects from 2006 to June 2014.
The research related to musculoskeletal effects, IQ and neurological manifestations, cancer cardiovascular disease, kidney disorders, thyroid disease, Down syndrome, and mortality from any cause.
As well as examining areas with artificially fluoridated water, the HRB also examined the research in areas where fluoride occurs naturally in the water and at much higher levels than treated water.
Dr Marie Sutton, the lead author of the report, said research specifically examining the association between community water fluoridation and health effects was scarce. “Most of the studies reviewed are not of a suitable design to prove, or disprove, a link between fluoride consumption and negative health effects,” she said.
Two studies that were reviewed did suggest a potential link between fluoride and negative health effects in the areas of bone health and thyroid disease. However, Dr Sutton said both studies did not have the “methodological rigour” required to provide “conclusive evidence” that fluoride was responsible for the negative health effects.
The Irish Dental Association welcomed the HRB review. President Anne Twomey said none of the previous major reviews had concluded that community water fluoridation posed a known risk to general health, or had suggested halting water fluoridation.
“These and other reviews which dealt solely with oral health show a significant benefit to dental health and through this to general health,” she said.