Fluoride is expected to be added to drinking water across the country after Britain’s chief medical officers concluded that the mineral would cut tooth decay. Chris Whitty, the chief medical officer for England, and his counterparts in Wales, Scotland and Northern Ireland cited estimates by Public Health England that adding more fluoride to water supplies would reduce cavities by 17% among the richest children and 28% among the poorest. They also dismissed safety concerns saying there is no evidence that ionised form of the element fluorine causes cancer and condemned “exaggerated and unevidenced” suggestions about health risks. Fluoride is found in low levels in water and is known to protect teeth. In an evidence review published on Thursday, the medical officers concluded: “As with all things in medicine and public health there is a balance of risk and benefit. There is unquestionably an issue with tooth decay in the UK and an entrenched inequality which needs to be addressed. Fluoridation of water can reduce this common problem. “On balance, there is strong scientific evidence that water fluoridation is an effective public health intervention for reducing the prevalence of tooth decay and improving dental health equality across the UK. It should be seen as a complementary strategy, not a substitute for other effective methods of increasing fluoride use.” Tooth decay is the biggest cause of hospitalisation for children aged from five to nine. In the 2019 school year, 23.4% of five-year-olds in England and 26.5% of four- to five-year-olds in Scotland had experienced damage to their teeth. Local authorities are now responsible for deciding whether to add fluoride to local water supplies. The health bill going before MPs will give Sajid Javid, the health secretary, the power to order fluoridation across the country. However, any move towards centralisation is not expected soon. Javid tweeted a link to the chief medical officer’s conclusions and wrote: “Good to see UK CMOs examining how water fluoridation can improve oral health & prevent tooth decay which disproportionately affects more deprived groups. Reinforces why our health and care bill will make it simpler to expand water fluoridation schemes.” In England, only 5.8 million people drink water with fluoride, some of which occurs naturally. It is more common in other countries including the United States, Brazil, Australia, Canada, Spain, South Korea and New Zealand. The World Health Organization recommends a safe limit of about twice the levels that fluoridation schemes are likely to set. Whitty and his colleagues said that levels must be “closely monitored” by drinking water inspectors. The British Dental Association (BDA) welcomed the statement from the four UK chief medical officers. Eddie Crouch, the BDA chair, said: “Every dentist will thank the CMOs for recognising the lasting benefits water fluoridation could bring to the nation’s oral health. “However, these gains are purely theoretical without upfront investment. Spending here will pay for itself, and ministers need to show they are willing to seize the moment. We need a joined-up approach. Covid has left millions unable to access care, and deep inequalities are now set to widen.” The Oral Health Foundation said it fully supports the statement from the UK chief medical officers on the effectiveness of fluoridated water and how beneficial it can be in reducing tooth decay. The argument over whether the mineral should be added to water supplies has been long running. In 2014, Public Health England urged councils in England to add fluoride to improve dental health. In Australia, dentists and doctors in Queensland reported “extensive tooth decay” in 2019 in parts of the state that refuse to add fluoride to the water supply, especially among children and elderly people. Indigenous children, many of whom live in communities without fluoride, had a 70% rate of tooth decay. The rate was 55% among all Queensland children aged between five and 15. In 2016, Australia’s chief health and medical research agency said adding the mineral to drinking water does not lower a person’s IQ, cause cancer or cause any other negative health effects after analysing more than 3,000 studies.