Major Science Review Shows No Evidence For Water Fluoridation
from Newsweek, June 29, 2015.
Fluoridation May Not Prevent Cavities, Scientific Review Shows
If you’re like two-thirds of Americans, fluoride is added to your tap water for the purpose of reducing cavities. But the scientific rationale for putting it there may be outdated, and no longer as clear-cut as was once thought.
Water fluoridation, which first began in 1945 in Grand Rapids, Michigan, and expanded nationwide over the years, has always been controversial. Those opposed to the process have argued—and a growing number of studies have suggested—that the chemical may present a number of health risks, for exampleinterfering with the endocrine system and increasing the risk of impaired brain function; two studies in the last few months, for example, have linked fluoridation to ADHD and underactive thyroid. Others argue against water fluoridation on ethical grounds, saying the process forces people to consume a substance they may not know is there—or that they’d rather avoid.
Despite concerns about safety and ethics, many are content to continue fluoridation because of its purported benefit: that it reduces tooth decay. The Centers for Disease Control and Prevention’s Division of Oral Health, the main government body responsible for the process, says it’s “safe and effective.”
You might think, then, that fluoridated water’s efficacy as a cavity preventer would be proven beyond a reasonable doubt. But new research suggests that assumption is dramatically misguided; while using fluoridated toothpaste has been proven to be good for oral health, consuming fluoridated water may have no positive impact.
The Cochrane Collaboration, a group of doctors and researchers known for their comprehensive reviews—which are widely regarded as the gold standard of scientific rigor in assessing effectiveness of public health policies—recently set out to find out if fluoridation reduces cavities. They reviewed every study done on fluoridation that they could find, and then winnowed down the collection to only the most comprehensive, well-designed and reliable papers. Then they analyzed these studies’ results, and published their conclusion in a review earlier this month.
The review identified only three studies since 1975—of sufficient quality to be included—that addressed the effectiveness of fluoridation on tooth decay in the population at large. These papers determined that fluoridation does not reduce cavities to a statistically significant degree in permanent teeth, says study co-author Anne-Marie Glenny, a health science researcher at Manchester University in the United Kingdom. The authors found only seven other studies worthy of inclusion dating prior to 1975.
The authors also found only two studies since 1975 that looked at the effectiveness of reducing cavities in baby teeth, and found fluoridation to have no statistically significant impact here, either.
The scientists also found “insufficient evidence” that fluoridation reduces tooth decay in adults (children excluded).