“… Monday's analysis digs deeper into the data behind these conclusions. It looks at a few dozen foreign studies that other researchers have conducted, mostly in China and India, and finds an association between high levels of fluoride and a small decrease in children's IQ.
… The analysis is controversial. The paper was published alongside two editorials in
JAMA Pediatrics. One, by Steven Levy, a public health dentist at the University of Iowa,
questioned the analysis's methods and disagreed with its conclusions. The other, by a trio of children's health researchers,
supported its findings.
Using this analysis — which is inconclusive at levels of fluoridation below 1.5 mg/L — to inform the debate over low levels of fluoride in drinking water feels like a stretch to fluoridation supporters like Levy.
"The major problem is that the science is not as strong as it's presented by these authors," he says. For instance, the study authors write in the paper's abstract that fluoride exposure seems linked (in certain studies) with lower IQ at levels even below 1.5 mg/L, but Levy notes that the data they provide aren't conclusive.
… He points out that some of the more recent fluoride studies, which he thinks are better designed, found no negative effect on IQ, and he thinks they should have been given more weight in the recent analysis.
To others, the analysis published this week makes a strong enough case out of imperfect evidence for action. "What the study does, or should do, is shift the burden of proof," says Dr.
Bruce Lanphear, a children's health researcher at Simon Fraser University, who co-authored the other editorial, which supported the paper's findings. "The people who are proposing fluoridation need to now prove it's safe. …”
——
From the cited NPR story. I have no objections to this data being used to prod further dedicated, high quality US research on the matter, but given the known value of fluoridation of water, no recommendations should be based on such a review of existing Indian and Chinese studies.
