Something in the water?

In Stanley Kubrick’s movie Dr. Strangelove, Commander Jack D Ripper calls fluoride ‘a foreign substance’ that ‘is introduced into our precious bodily fluids’.

In the UK, Birmingham and West Midlands authorities are currently debating whether or not to allow this ‘foreign substance’ into their water. Many in the public health community might hail the benefits of fluoridation, but some remain convinced that it is unsafe. Why?

Michael W Easley, director of the National Centre for Fluoridation Policy and Research, calls fluoridation ‘a perfect public health intervention’. A form of nutritional supplementation, fluoridation indiscriminately aids whole populations. It is endorsed by most public health organisations, from the Centers for Disease Control to the American Cancer Society.

But others worry about the purity and sources of fluoride. They claim specifically that fluoridation decreases bone mineral density and heightens the risk of fractures in older women.

Yet reports in the British Medical Journal (BMJ) found that long-term exposure to fluoridated drinking water does not increase the risk of fracture (1). Although earlier ecological studies found that fluoridation increased the risk of hip fracture, the BMJ noted that they were based on community level data and could not control for variables at the individual level.

The BMJ concluded that fluoridation may actually reduce, not increase, the risk of fractures in older white women, and that fluoridation may be one of the most cost-effective methods for reducing the incidence of osteoporosis-related fractures.

And what happens when water-borne fluoride is combined with the fluoride in food and toothpaste? A Canadian report released in January 2001 suggested that fluoridation may carry as many risks as benefits.

Dr Hardy Limeback, a University of Toronto dentistry professor, argued against any need to put fluoride in the water because of its presence in the general diet. The fluoridated water could easily lead to fluorosis when combined with other regular dietary sources of fluoride. In its mildest form, fluorosis causes small, white, virtually invisible opaque areas on teeth. In its most severe form, fluorosis results in brownish mottling or spotting.

But there are others whose fears are based more on eccentricities than on medical evidence. Just as Dr. Strangelove’s Jack D. Ripper saw fluoridation as the communists’ insidious tool of domination, many of today’s activists see fluoridation as just a small part of a much larger conspiracy. Some even view it as a form of forced medication and mental and physical control.

Unfortunately, the fluoridation issue remains unsettled. The Environmental Protection Agency (EPA), despite its support of fluoridation, recently requested that the National Research Council’s Board on Environmental Studies and Toxicology investigate the potential harmful effects of fluoride, finding ‘inconsistencies in the fluoride toxicity database and gaps in knowledge’.

But what is known for sure is that fluoride helps prevent caries (tooth decay). Providing communities with fluoridated water is a convenient way to prevent caries, saving the time and money it would take to treat them. The claim that fluoride increases the risks of fractures in older women lacks convincing evidence. And though the concern over fluorosis might be valid, evidence for this is sparse, too.

With most of the evidence showing that fluoridated water is both useful and safe, there’s no reason to give up on it yet.

Molly Sullivan is research assistant at the Statistical Assessment Service (STATS), a non-profit, non-partisan research organisation based in Washington, DC.

(1) British Medical Journal, 7 October 2000