Tuesday, September 19, 2000

Research shows low fluoride levels safe - expert

While the debate about fluoridation and bone fractures often raged at an emotional level, the scientific evidence was that fluoride could be added to water at safe levels without damaging humans, a leading researcher has told a conference in Cork.

Addressing a joint meeting of the British Association for the Study of Community Dentistry and the European Association of Dental Public Health at UCC, Prof Cyrus Cooper, professor of rheumatology at the University of Southampton, said he believed fluoridation was safe. "While it would be impossible to exclude completely any risk of increase in fractures due to fluoridation, all the current scientific literature suggests that such a risk, were it to occur, would be extremely small and of no clinical relevance," Prof Cooper said.

Some of the studies in the UK were inherently weak, he said, because they were based on towns, where the results could differ widely due to any number of confounding factors, such as environment, lifestyle, etc. However, four studies recently published in the Lancet concentrated on individuals and the results indicated no increased risk of bone fracture due to fluoridation.

Also, when all the results of worldwide data were collated, no evidence could be found to indicate fluoridation and bone fracture were related. "In places around the world where fluoride was added to water at 10 parts per million (ppm) the human skeleton was found to be affected but the question is what happens to the skeleton when fluoride is added, as is the case in Ireland, at 1ppm. Then, it is safe and there is no evidence of risk," he said. "I would say the Irish fluoridation programme is a safe one."

When fluoride was ingested, 50 per cent was absorbed by bone and the remaining 50 per cent was passed from the body through urine, he said. High doses of fluoride could lead to irregularities in bone formation and while the debate was emotional at times, the evidence was that at lower levels, water fluoridation was safe.

dhogan@irish-times.ie