WHICH routinely ingested substance is alleged to increase risk of cancer, thyroid disease, sickle-cell anaemia, depression, infertility, birth defects, sudden infant death syndrome, low IQ, Alzheimer’s, headache, chronic fatigue, violent behaviour, musculoskeletal damage, gastrointestinal problems, hair loss, chronic dermatitis and hives?
The answer, of course, is fluoride, which has been the target of health scare campaigns pretty much since it was first added to Australian drinking water to improve dental health back in the 1950s.
As if making you bald and stupid isn’t enough, anti-fluoride campaigners also claim that the substance either doesn’t prevent tooth decay or actually increases it.
One website even makes the startling assertion that Adolf Hitler fluoridated the German water supply in the 1930s to turn the populace into easily brainwashed zombies, so that he could “numb society and take over”.
You probably won’t be surprised to learn that health professionals are often targets of online conspiracy theories, accused of being in the pockets of major corporations that stand to profit from fluoridation programs.
Residents of regional Queensland may not have to worry about their IQs being affected, as the water supply in many areas of that state is no longer fluoridated.
The regional cities of Mackay and Gladstone recently voted to join other centres in abandoning fluoridation, a decision that has caused consternation in dental circles.
“Lunacy”, was how a spokesman for the Australian Dental Association described the move, saying that people’s health was being put at risk by “these lunatic, conspiracy-theory fringe groups”.
Among regional Queensland cities, Townsville is a notable exception in having fluoridated its water since the 1960s.
That’s given the locals something to smile about. According to Queensland Health, the average number of cavities in the permanent teeth of Townsville children aged 12–14 years is just over half of that in children from regions of northern Queensland without a history of fluoridation (0.7 v 1.3).
The National Health and Medical Research Council (NHMRC) recently completed a comprehensive review of the evidence on the safety and efficacy of fluoridation.
The update was conducted partly in response to a 2015 Cochrane review that was widely reported as casting doubt on the health benefits of the practice.
A Newsweek article, for example, said that assumptions about the evidence base for fluoridation now seemed “dramatically misguided”.
Really? In fact, the Cochrane reviewers found that water fluoridation was “effective at reducing levels of tooth decay among children”.
However, no studies of the effects of fluoridation for preventing caries in adults met the review’s inclusion criteria, thus they did not find evidence of benefit in adults.
Their review has been critiqued for its methodology and inclusion criteria (in this Nature article, for example).
But, whether you accept those criticisms or not, the conclusion that fluoridation works in children and might or might not work in adults doesn’t exactly seem like a dramatic overturn of the conventional wisdom.
The NHMRC certainly didn’t think so, reporting on the long history of research that shows water fluoridation helps to reduce tooth decay in children and adults.
Most importantly, the NHMRC review of the evidence found that community water fluoridation within the current Australian range does not cause harm.
Sadly, though, that message probably won’t hold much sway with the fearmongers.
Jane McCredie is a Sydney-based science and health writer, journalist and publisher.
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