Why I Changed my Mind About Water Fluoridation

WHY I CHANGED MY MIND ABOUT WA TER FL UORIDA TION JOHN COLQUHOUN* Former Advocate To explain how I came to change my opinion about water fluoridation, I must go back to when I was an ardent advocate of the procedure. I now realize that I had learned, in my training in dentistry, only one side of the scientific controversy over fluoridation. I had been taught, and believed, that there was really no scientific case against fluoridation, and that only misinformed lay people and a few crackpot professionals were foolish enough to oppose it. I recall how, after I had been elected to a local government in Auckland (New Zealand's largest city, where I practiced dentistry for many years and where I eventually became the Principal Dental Officer ) , I had fiercely—and I now regret rather arrogantly—poured scorn on another Council member (a lay person who had heard and accepted the case against fluoridation) and persuaded the Mayor and majority of my fellow councillors to agree to fluoridation of our water supply. A few years later, when I had become the city's Principal Dental Officer, I published a paper in the New 7£aland DentalJournal that reported how children's tooth decay had declined in the city following fluoridation of its water, to which I attributed the decline, pointing out that the greatest benefit appeared to be in low-income areas [I]. My duties as a public servant included supervision of the city's school dental clinics, which were part of a national School Dental Service that provided regular six-monthly dental treatment, with strictly enforced uniform diagnostic standards, to almost all (98 percent) school children up to the age of 12 or 13 years. I thus had access to treatment records, and therefore tooth decay rates, ofvirtually all the city's children. In the study I claimed that such treatment statistics "provide a valid measure of the dental health of our child population" *School of Education, University ofAuckland, Private Bag 92015, Auckland, New Zealand.© 1997 by The University of Chicago. AU rights reserved. 0031-5982/97/4101-1042$01.00 Perspectives in Biology and Medicine, 41, 1 ¦ Autumn 1997 | 29 [I]. That claim was accepted by my professional colleagues, and the study is cited in the official history of the New Zealand Dental Association [2]. INFORMATION CONFIDED I was so articulate and successful in my support ofwater fluoridation that my public service superiors in our capital city, Wellington, approached me and asked me to make fluoridation the subject of a world study tour in 1980—after which I would become their expert on fluoridation and lead a campaign to promote fluoridation in those parts of New Zealand which had resisted having fluoride put into their drinking water. Before I left on the tour my superiors confided to me that they were worried about some new evidence that had become available: information they had collected on the amount of treatment children were receiving in our school dental clinics seemed to show that tooth decay was declining just as much in places in New Zealand where fluoride had not been added to the water supply. But they felt sure that when they had collected more detailed information on all children (especially the oldest treated, 12-13 year age group) from all fluoridated and all nonfluoridated places [3] — information which they would start to collect while I was away on my tour— it would reveal that the teeth were better in the fluoridated places: not the 50 to 60 percent difference that we had always claimed resulted from fluoridation, but a significant difference nonetheless. They thought that the decline in tooth decay in the nonfluoridated places must have resulted from the use of fluoride toothpastes and fluoride supplements, and from fluoride applications to the children's teeth in dental clinics, which we had started at the same time as fluoridation. Being a keen fluoridationist, I readily accepted their explanation. Previously, of course, we had assured the public that the only really effective way to reduce tooth decay was to add fluoride to the water supply. WORLD STUDY TOUR My world study tour took me to North America, Britain, Europe...