Rooster syndrome and the anti-fluoride crowd.

I live in a part of the world where the print media is dominated by Murdoch publications, and since I am no longer prepared to pay money to support the evil empire, I have a shortage of good sources of analysis. Recently I noticed a newsstand offering free copies of the Epoch Times and decided to give it ago. Until today, I was quite impressed – good coverage of Chinese politics and even some local stuff. I’d almost overcome my skepticism about the its mysterious source (Is it a Falun Gong propaganda rag?). But then, in the latest edition, I came across an article with the headline: Water fluoridation affects children’s IQ.

This article was written by W. Gifford-Jones, M.D. (apparently the pen-name of Dr. Ken Walker, a Toronto gynecologist), and he focuses on a recent study (here) from the Harvard School of Public Health. The study has also been headlining at all the anti-fluoridation websites, which are gleefully claiming it justifies their stance. It is in fact a systematic review, based on 27 studies, mostly carried out in China. The authors’ Conclusion is as follows:

The results support the possibility of an adverse effect of high fluoride exposure on  children’s neurodevelopment. Future research should include detailed individual ­level information  on prenatal exposure, neurobehavioral performance, and covariates for adjustment.

But in a classic case of rooster syndrome, Gifford-Jones writes:

Now, a report from the Harvard School of Public Health (HSPH), says that the use of fluoride causes a decrease in children’s IQ.

This is nonsense, of course. There is no finding of cause and effect. The study found a correlation between fluoride concentrations and IQ, and sensibly, the authors recommend that further investigation is required. They acknowledge that there are many sources of uncertainty  – including that “each of the articles reviewed had deficiencies, in some cases rather serious ones” and “the estimated decrease in average IQ … may seem small and may be within the measurement error of IQ testing”. (A HSPH press release points out that the average discrepancy corresponded to about 7 IQ points). John Underhay at Skeptic North and Steven Novella at Science-Based Medicine have further quibbles.

Gifford-Jones goes on to claim:

Researchers discovered that children in the low-fluoride area had a 28 percent chance of being normal, bright, or of high intelligence.

In the high-fluoride area, the figure was 8 percent. They also found that in the low-fluoride community, 6 percent of children suffered from mental retardation compared to 15 percent in the high-fluoride community.

yet these figures appear nowhere in the paper.

So I’m pretty disillusioned with the Epoch Times. There’s no excuse for poor science journalism.