UK report recommends further research on water fluoridation and health

September 10, 2002

Susan Mayor London

Further research on the health effects of adding fluoride to drinking water is needed—especially studies of people’s total exposure to fluoride, a working group set up by the Medical Research Council recommended in a report published last week.

Fluoride has been added to piped drinking water in some areas of the United Kingdom, as well as in other countries, for several decades to improve dental health. However, public support for the measure has wavered after claims that water fluoridation might be associated with health problems.

The Department of Health asked the council’s working group to identify areas of uncertainty on the balance of risks of water fluoridation and to recommend research needed to clarify the situation.

Dr Paul Harrison, acting director of the council’s Institute for Environment and Health, Leicester, who chaired the group, said: "There is no reason to think that water fluoridation is responsible for any adverse health effects. But there is a lack of research on some important aspects, which is why we’re highlighting the need for more research."

One of the main recommendations made by the working group was to compare the amount of fluoride that the body absorbs from naturally fluoridated water supplies with the amount absorbed from artificially fluoridated water. It has previously been assumed that fluoride absorption from either source was similar.

Members of the working group considered that this was a reasonable assumption but recommended that research be carried out to discover whether there were any differences, including looking at the influence of water hardness on fluoride absorption.

The report also calls for new studies on the extent of dental fluorosis, a condition which affects the appearance of teeth and which is associated with a high intake of fluoride.

Dr Harrison explained: "In the past, people got most of their fluoride from their water. This has changed with the wider use of toothpastes and other dental healthcare products containing fluoride. We need a better understanding of how much fluoride we’re all absorbing."

The Department of Health has agreed to commission a project on the absorption of fluoride, in accordance with the report’s recommendations.

The report also reviewed a range of health issues relating to fluoride, including cancer, effects on the immune system and on reproduction, and birth defects, which have been anecdotally associated with water fluoridation. It found no evidence linking fluoridation to cancer in general, or to specific cancers, but recommended an updated analysis to provide definitive data on cancer rates since water fluoridation was introduced.

The group found no evidence for associations between fluoridation and other health effects so recommended no specific research, apart from keeping the issues under review.

Dr Harrison considered that the review of water fluoridation was part of a more general effort to involve the public more in policy making. "Scientists and policy makers have realised that communication with the public is important. Communities should be informed and involved in public health measures that affect them."