Drinking fluoridated tap water for more than 50 years does not lead to declines in memory or cognitive function among older adults, according to researchers at Trinity College Dublin in Ireland who analyzed medical data from about 2,500 people with an average age of 65, infohub.kz reports.
The findings, published in the Journal of Dental Research, rebut concerns that water fluoridation programs harm the brain when the substance is kept at standard concentrations, the science portal ScienceAlert reports.
The scientists used data from the Irish Longitudinal Study on Ageing (TILDA), matching where participants lived since Ireland introduced a nationwide water fluoridation program in 1964 against the results of two different tests assessing mental ability. Participants were divided into low, medium and high exposure groups based on fluoride levels in their local water supplies. The comparison showed no statistical link between the amount of fluoride received over the decades and cognitive health.
Lead author Vinay Sharma noted that no negative effect was recorded even in a subgroup of 124 participants who drank fluoridated water during their first five years of life, though the small sample size means this finding requires caution. Co-author Michael Crowe stressed that fluoridation remains one of the most effective ways to prevent tooth decay, and that the data confirm its safety for the nervous system, unlike the cases of toxic fluoride excess described in earlier studies.