Fluoride in drinking water wards off tooth decay

Fluoride in drinking water can cut tooth decay in adults, even those who did not drink fluoridated water as children, a new study has claimed.
Researchers at the University of North Carolina at Chapel Hill and the University of Adelaide, Australia, produced the strongest evidence yet that fluoride in drinking water provides dental health benefits to adults.
In the first population-level study of its kind, the study found that fluoridated drinking water prevents tooth decay for all adults regardless of age, and whether or not they consumed fluoridated water during childhood.
"It was once thought that fluoridated drinking water only benefited children who consumed it from birth," explained Gary Slade from UNC.

"Now we show that fluoridated water reduces tooth decay in adults, even if they start drinking it after childhood. In public health terms, it means that more people benefit from water fluoridation than previously thought," Slade said in a statement.
The researchers analysed national survey data from 3,779 adults aged 15 and older selected at random from the Australian population between 2004 and 2006.

Survey examiners measured levels of decay and study participants reported where they lived since 1964. The residential histories of study participants were matched to information about fluoride levels in community water supplies.
The researchers then determined the percentage of each participant's lifetime in which the public water supply was fluoridated.

The results, published online in the Journal of Dental Research, found that adults who spent more than 75 per cent of their lifetime living in fluoridated communities had significantly less tooth decay (up to 30 per cent less) when compared to adults who had lived less that 25 per cent of their lifetime in such communities.