Public Health England statement
Consider mass fluoridation of water, says health body
Adding fluoride to water supplies should be considered by councils to improve dental health, the government's public health advisory body says.
Public Health England urged councils to act after reviewing the impact of water fluoridation on children in areas where it has been introduced.
About 6m people - 10% of the country - currently live in areas with fluoridated water supplies.
PHE said it was a "safe and effective" measure.
It found good evidence it had reduced tooth decay and hospital admissions for dental problems.
The review found there were 45% fewer children aged one to four admitted to hospital for tooth decay in fluoridated areas.
Levels of general tooth decay were 15% lower for five-year-olds and 11% lower for 12-year-olds.
In deprived areas the impact for general tooth decay was even greater.
PHE also looked for signs of harms but found none. It has been suggested water fluoridation can increase the risk of some cancers, hip fractures and Downs syndrome. Fluoride's main benefit is in helping reduce the risk of tooth decay.
But critics argue that the long-term health risks are unknown and different studies have produced contrasting results. Sue Gregory, PHE's director of dental public health, said: "These findings highlight the important contribution that water fluoridation makes."
She said councils would need to consult their local populations on the issue and conceded there were some technical hurdles to overcome. Water zones tend to span several local authority areas and so fluoridation could require agreement across regions.