October 29, 2000

Fluoride's Foes Find Support in Research

Arguments for and against fluoride have changed in the 24 years since a large number of Utahns last confronted them in the ballot booth, but one thing has not: the charged emotion of the debate.

To most public health officials, doctors, dentists and nurses, the issue is clear-cut: Thousands of studies over the past 50 years have proved that adding fluoride to the water supply is the safest, easiest and cheapest way to reduce tooth decay. The Centers for Disease Control and the American Dental Association report fluoridated water reduces tooth decay 35 percent to 60 percent.

Arguments to the contrary, they say, are pure bunk perpetuated by fear mongers.

Opponents counter that there are good reasons not to fluoridate water. It's wasteful, since much water goes to lawns and laundry. It's an infringement on the rights of those who do not want fluoridated water, they say, and insulting to force them to pay for it.

But the most polar argument revolves around the science of fluoride and its effects on the body and teeth.

It is that issue that will be on the minds of Salt Lake County, Davis County and Logan voters as they decide Nov. 7 whether to support fluoridation. Residents of the Cache County cities of Smithfield, Providence, Hyrum and Nibley will cast nonbinding votes on the issue.

This is the first big fluoride push since 1976, when Utah voters narrowly rejected the additive. Tooele voters have turned back fluoride three times.

Meanwhile, the rest of the nation is increasingly choosing fluoridation. Close to 150 million people drink fluoridated water, and Utah, with just 3 percent of its water fluoridated, is the least fluoridated state.

Opponents who want to keep it that way -- and who often are accused of relying on suspect research published in obscure journals -- this time point to studies in the respected Journal of the American Dental Association (JADA).

John Featherstone, a cavity researcher at the University of California at Berkeley, wrote in July that fluoride's primary benefit is topical. His research showed that when fluoride is applied directly to teeth, it prevents cavities, helps teeth rebuild enamel when cavities start and inhibits bacteria that lead to dental decay.

"Fluoride incorporated during tooth development is insufficient to play a significant role in caries [cavity] protection," Featherstone wrote.

Opponents say the study bolsters their argument that topical applications of fluoride -- toothpaste and fluoride rinses and gels at the dentist's office or in school -- are the best way to get cavity-fighting fluoride to those who want it. Ingesting fluoride is unnecessary, they argue.

Early Benefit: But advocates say fluoridated water is the best way to get -- and keep -- fluoride on the teeth. Not only does the fluoride bathe the teeth any time a person swallows water or eats food prepared with water, it also enters the saliva through the bloodstream and the saliva keeps coating the teeth with fluoride throughout the day, says Ariel Thompson of Logan.

Thompson is a former National Institutes of Health dental researcher and microbiologist who teaches at Utah State University and the University of Utah.

Fluoride tablets, on the contrary, produce a fluoride spike in a person's saliva for only about four hours.

It's true that research since the 1980s has proved fluoride's benefits are mainly for teeth once they have come in, said Michael Easley, director of the National Center for Fluoridation Policy and Research in Buffalo, N.Y. That became clear when researchers found adults, like children, had less tooth decay in communities with fluoridated water, he said.

But Easley and Thompson disagree with Featherstone's assertion that fluoride does not play a significant role in strengthening teeth during their development.

"He is in the minority. There is a definite benefit for children drinking fluoridated water as their teeth are developing. That has been the evidence for years," Easley said.

That's just one of many reasons why numerous national medical organizations -- including the American Dental Association, American Medical Association and the Centers for Disease Control and Prevention -- endorse fluoridation. The CDC ranks it among the 20th century's top 10 public health achievements.

But anti-fluoridationists also point to a second JADA article, published in June. It notes that fluorosis is increasing throughout the United States.

Fluorosis, from too much fluoride as teeth are developing, usually shows up as a white, lacy coating on the teeth. Severe fluorosis, rarely seen in this country, stains the teeth brown, causes pits or even breakdown of the enamel. Cosmetic treatments to get rid of fluorosis are expensive.

Incidence of Fluorosis: David Pendrys, a researcher at the University of Connecticut's School of Dental Medicine, studied nearly 2,000 children in Connecticut and Massachusetts, comparing fluorosis in those who grew up with and without fluoridated water.

While there was more fluorosis in nonfluoridated areas -- Pendrys found fluorosis among 39 percent of those from nonfluoridated areas and 34 percent from fluoridated communities -- the causes in both were similar.

In most cases, children with fluorosis were using too much fluoridated toothpaste -- more than a pea-size amount -- too often and too young to avoid swallowing it. Improper use of fluoride tablets was also to blame.

Many of the cases stemmed from tablets prescribed before 1994, when the dosage of fluoride given children and infants was higher. But in some cases, doctors and dentists had prescribed supplements to children drinking fluoridated water.
In fluoridated communities, some fluorosis was caused by use of fluoridated water to mix powdered baby formula -- before manufacturers reduced fluoride additives in 1979 -- Pendrys found.

Jay R. West, a Layton orthodontist, says that although he has seen significant amounts of fluorosis in his practice, he was astounded by the levels reported in the study.
"One has to wonder if the addition of more fluoride to the dental environment through drinking water is a wise decision at this time," West said.

Mark Flack of Salt Lake City, one of the few dentists publicly fighting fluoridation, says more research is needed on fluoride's effect on the body, whether it causes cancer or brittle bones and hip fractures, and whether fluoridated water can bring on lead poisoning.
"You could put the entire National Institutes of Health on a 100-year study on fluoride alone and they'd never have enough to study this right," he said.

The study opponents use to question a link between fluoride and lead poisoning was published by Roger Masters, a political scientist, and Myron Copland, a chemical engineer, in the International Journal of Environmental Studies, printed in Malaysia last year.

They studied blood samples of 280,000 Massachusetts children and concluded that kids in communities with fluoridated water have higher lead levels in their blood. The pair concluded that the form of fluoride used to treat community water causes human cells to absorb lead.

Scientists who took the children's blood samples, however, decried the study's conclusions, and an Environmental Protection Agency chemist wrote a rebuttal paper claiming that it is chemically impossible for the fluoride to behave in water as Masters and Copland claim it does.

The larger scientific community also dismisses as "ridiculous" the research linking fluoride to cancer. Opponents say fluoride changes the enzymes in the body, weakening its ability to fight cancer. If there were a link, it would have shown up after 50 years of fluoride use in community water systems, say advocates.

Studies linking fluoride to hip fractures, however, have been mixed. Opponents point to 1990 research involving senior citizens in Brigham City, performed by University of Utah researchers. Brigham City began fluoridating its water in the 1960s.

While they found a possible link between fluoride and hip fractures, the researchers noted their study was far from conclusive.

Fluoride proponents say they now have all the assurance they need that there is no connection, particularly after an exhaustive study involving 9,000 people reported this month in the British Medical Journal.

"The hip fracture issue is about put to bed," Thompson says.

Opponents often say it's unfair to fluoridate a community's water system when some people are allergic.

Flack says he occasionally sees patients with a sensitivity to fluoride if not an outright allergy. It shows up as a red rash or cracks and blisters around the mouth.

But fluoridation proponents argue it is the high level of fluoride in toothpaste, 1,000 parts per million, that causes sensitivities, and that water, fluoridated at 1 part per million, will not have the same effect.

Joseph Newton, a retired Salt Lake City pediatrician who gathered petition signatures to force fluoride onto Salt Lake County's ballot, says he himself is sensitive to fluoridated toothpaste.

The solution, he adds, is simple: Change to a different toothpaste and reach for a glass of fluoridated water.

Salt Lake Tribune