The truth about Fluoride

Thirty-somethings who grew up in the era before fluoride was added to toothpaste tend to view it as the best thing since sliced bread. A mouthful of fillings, and painful memories of visits to the dentist, make us extra-conscientious about using fluoride toothpaste, drops and rinses on our offspring. But could they be getting too much of a good thing?

A campaign to highlight the risks of fluoride to children's teeth is to be launched on "National Fluoride Free Day" next week. Its supporters estimate that the increase in the number of dental products containing fluoride, together with its presence in substances such as tea and fuel fumes, means many of us may be consuming too much, and that this can lead to serious health problems. They argue that further fluoridation of the water supply would make the problem worse.

On the other side of the fence is the pro-fluoride lobby, supported by the medical establishment, including the British Medical and Dental Associations. Earlier this month they called for action to extend fluoridation of water, on the grounds that it can reduce tooth decay by up to about 50 per cent, particularly among children in deprived areas. They also maintain that at the levels permitted in Britain, fluoridation presents no health danger.

So who is right?

At the moment, some 5.5 million people in Britain, most of them in the West Midlands and North-east, are drinking water which has been artificially fluoridated. A mineral found naturally in soil and water, fluoride strengthens the tooth enamel, making it more resistant to attack by the acids formed from sugar. It is most effective during the development of teeth in childhood, when it is taken up into the structure of the tooth enamel itself. There is little doubt that the addition of fluoride to toothpaste in the early 1970s (along with other factors such as changes in diet and education), has been a major factor in reducing childhood tooth caries. In 1973, 7 per cent of 12-year-olds had no tooth decay; 20 years later this figure had increased to 50 per cent.

Ingested in large quantities fluoride is certainly toxic and has been linked to bone disorders, hip fractures, kidney failure, stomach and intestinal problems, infertility and even genetic damage. Excessive amounts in the bloodstream - caused by, say, a child habitually swallowing toothpaste, or sucking the tube - can result in fluorosis, a permanent, unsightly mottling of the enamel which occurs when the second set of teeth is developing in the gums. The families of more than 200 British children with dental fluorosis are demanding Government compensation, arguing that toothpaste should carry stronger warnings about fluoride's risks.

But how much is too much - and does fluoridating the water put us at risk of excess fluoride intake? All the major studies of water fluoridation have shown that at the level permitted in Britain (one part per million), there is no evidence of any risk to health. (In parts of Africa and Asia, by contrast, where natural fluoride levels in the water range from 8-13 ppm, bone and joint problems are common). However, in about 10 per cent of children, fluoridation does result in "mild" fluorosis - a condition where fine white lines or markings, virtually invisible to the naked eye, appear on the teeth. These are not a health or cosmetic problem and are widely seen as a small price to pay for reducing tooth decay. Dental products have far higher fluoride concentrations than artificially fluoridated water: adult toothpaste for instance, contains 1,000 ppm or more.

The best way to avoid discoloured teeth in children is to ensure they use only children's toothpaste (which, at 250-400 ppm, has far lower fluoride concentrations) and to let them use a blob the size of a small pea twice a day. Small children should be prevented from swallowing toothpaste or sucking the tube At about seven, when they have conquered the art of spitting toothpaste out, children can use adult formulations.

If you wish to know if water in your area is artificially fluoridated, contact your water authority. If you violently object to fluoridated water it is possible to buy filtering equipment, which costs about pounds 300. If fluoride levels in your area are naturally low (and fluoride deficiency is as bad as fluoride excess), you may wish to consider using supplements or drops, although these should not be used without consulting a dentist and never in areas with a fluoridated water supply

Cherrill Hicks