FAN news letter

Newsweek’s Coverage of the Cochrane Review
Two weeks ago we told you about the new review of the effectiveness of fluoridation by the Cochrane Collaboration, which is considered to provide the gold standard in evidence based reviews of health science by doctors and researchers.  The authors found very little evidence that fluoride is effective in reducing dental decay, but did find evidence confirming that fluoridation increases fluorosis rates.   
On Monday, Newsweek published a great article by journalist Douglas Main on the Cochrane review, giving it widespread coverage in the US.  The article, entitled “Fluoridation May Not Prevent Cavities, Scientific Review Shows,” provides the best coverage of the review we’ve seen yet, and is a must-read and must-share for anyone living in a country that allows fluoridation.  Some key points from the article include:

• “The review identified only three studies since 1975—of sufficient quality to be included—that addressed the effectiveness of fluoridation in the population at large. These papers determined that fluoridation does not reduce cavities to a statistically significant degree, says study co-author Anne-Marie Glenny, a health science researcher at Manchester University in the United Kingdom.”

• One 2001 study covered in the Cochrane review of two neighboring British Columbia communities found that when fluoridation was stopped in one city, cavity prevalence actually went down slightly amongst schoolchildren, while cavity rates in the fluoridated community remained stable.  

• Studies that attest to the effectiveness of fluoridation were generally done before the widespread usage of fluoride-containing dental products like rinses and toothpastes in the 1970s and later, according to the recent Cochrane study. 

• Nearly all these papers were flawed in significant ways. For example, 70 percent of the studies made no effort to control for important confounding factors such as dietary sources of fluoride other than tap water, diet in general or ethnicity.  

• When it comes to fluoridation research, even the best studies are not high quality. Although this was already well-established, it doesn't seem to be well-known.

• One thing the review definitively concluded: Fluoridation causes fluorosis.

• But most scientists interviewed for this article don’t necessarily think fluoridation’s uncertain benefits justify its continuation without more stringent evidence, and argue for more research into the matter. 

The article also quotes several scientific and medical experts who agree that the concern over the practice ought to be taken seriously.  Here are just a few of the quotes: 

• “From the review, we’re unable to determine whether water fluoridation has an impact on caries levels in adults,” says study co-author Anne-Marie Glenny.

• “Frankly, this is pretty shocking,” says Thomas Zoeller, a scientist at UMass-Amherst uninvolved in the work. “This study does not support the use of fluoride in drinking water.”

• Trevor Sheldon concurred. Sheldon is the dean of the Hull York Medical School in the United Kingdom who led the advisory board that conducted a systematic review of water fluoridation in 2000, that came to similar conclusions as the Cochrane review.  The lack of good evidence of effectiveness has shocked him. “I had assumed because of everything I’d heard that water fluoridation reduces cavities but I was completely amazed by the lack of evidence,” he says. “My prior view was completely reversed.  There’s really hardly any evidence” the practice works, Sheldon adds. “And if anything there may be some evidence the other way.  When you have a public health intervention that’s applied to everybody, the burden of evidence to know that people are likely to benefit and not to be harmed is much higher, since people can’t choose,” Sheldon says. Everybody drinks water, after all, mostly from the tap. “Public health bodies need to have the courage to look at this review…and be honest enough to say that this needs to be reconsidered.”     

• Overall the review suggests that stopping fluoridation would be unlikely increase the risk of tooth decay, says Kathleen Thiessen, a senior scientist at the Oak Ridge Center for Risk Analysis, which does human health risk assessments of environmental contaminants.

• “The sad story is that very little has been done in recent years to ensure that fluoridation is still needed [or] to ensure that adverse effects do not happen,” says Dr. Philippe Grandjean, an environmental health researcher and physician at Harvard University.

• “The fact that there is insufficient information to determine whether fluoridation reduces social inequalities in dental health is troublesome given that this is often cited as a reason for fluoridating water,” say Christine Till and Ashley Malin, researchers at Toronto’s York University.

Earlier this year Newsweek also published two great articles on the recent studies linking artificially fluoridated water to a significant increase in hypothyroidism and ADHD.

Newsweek article on Hypothyroidism

Newsweek article on ADHD

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