Q: What about opponents’ claim that fluoride causes cancer?
1. Research offers strong evidence that this claim is unsupported speculation.
• A National Cancer Institute fact sheet reports: “Many studies, in both humans and animals, have shown no association between fluoridated water and cancer risk.”
• In 2011, after lengthy analysis and testimony from numerous experts in science and toxicology, California’s Office of Environmental Health Hazard Assessment voted unanimously not to classify fluoride as a cancer-causing substance.
• In 1993, a subcommittee of the National Research Council conducted a careful review of research — including more than 50 studies — to determine whether such a link existed. The subcommittee’s report concluded that the data did not demonstrate a link between fluoridated drinking water and cancer.
• A 1991 report by the Public Health Service found “there was no relationship between the introduction and duration of fluoridation and the patterns of cancer incidence rates, including those of the bone and joint” in humans.
• In 1985, Britain’s Working Party on Fluoridation (WPF) — a panel of medical and science experts — concluded “there is nothing in this extensive range of studies, covering altogether very large populations, to suggest that fluoride or fluoridation ‘is capable of inducing cancer or of increasing the mortality from cancer.’ ” The WPF added claims of a cancer-fluoride link are based on “elementary misinterpretations of the facts …”
2. The experts agree — fluoridated water does not cause cancer.
• A Harvard-led research team examined hundreds of bone samples from nine hospitals to determine whether there was a correlation between patients with a specific form of bone cancer and fluoride. This study, published in 2011 in the Journal of Dental Research (JDR), found there was no correlation.
• Opponents often refer to the so-called Bassin study that was published a few years before the JDR study. But the JDR study is much more credible than the Bassin study for at least three reasons:
o The National Cancer Institute approved the design of the JDR study.
o The JDR study analyzed actual fluoride levels in bone, which are a much more reliable way to measure fluoride consumption than the approach Bassin took (i.e., relying on people’s recollections of whether they lived in a fluoridated community and for how long they lived there).
o Even the graduate student who performed the Bassin analysis acknowledged that its conclusions were preliminary.
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