Archive for November, 2012


Duet, part 1

Apparently, different medical associations have widely different ways of assessing the validity of experimental evidence; case in point, aluminium and fluorine, two pollutants whose stories go hand in hand, and which will have the dubious honour of opening the long-promised Adele Gödel series. Consider this statement from the Alzheimer association:

A number of environmental factors have been put forward as possible contributory causes of Alzheimer’s disease in some people. Among these is aluminium. There is circumstantial evidence linking this metal with Alzheimer’s disease, but no causal relationship has yet been proved. As evidence for other causes continues to grow, a possible link with aluminium seems increasingly unlikely.

…which is, as we will presently see, a bunch of boloney, and compare it with the following one from the American Dental Association:

Studies conducted throughout the past 65 years have consistently shown that fluoridation of community water supplies is safe and effective in preventing dental decay in both children and adults.

…which is just as much boloney. This is not worrying in itself: the web is full of it anyhow. What is worrying is that the AA and the ADA seem to buy the obnoxious sausage at the same butcher’s. Let’s start with the Alzheimer’s Association: whereas neurology has made giant steps in understanding the disease in recent years, their review is from 2008. The most recent study cited is from 1998, and is only very indirectly related to the issue. The second most recent, from 1995, is about aluminium kinetics, not physiology, and the third, from 1990, treats the issue indirectly. What is most remarkable is that the review stops a few months short of the publication of a famous French article (available online here in its entirety), which directly contradicts the notion that “a possible link […] seems increasingly unlikely”. This study is monumental: carried over a 15-year  period and almost 2000 patients, it is of a quality almost never seen in the world of today’s slash-and-burn academic publications; its conclusions are unambiguous:

Analyses restricted to cases classified as Alzheimer’s disease […] suggested a deleterious effect of high aluminum intake.

Is it possible that the AA just didn’t know of this article? Not quite. As it happens, an odd side result emerged from the same set of data, a mere curiosity, really: people exposed to much silicon are less likely to contract the disease. This fact has been explained, chemically, by several people, most extensively by C. Exley: it is because silicon removes aluminium from the bloodstream. And, miraculously, the AA seems to know that: in another page, they happily admit it, albeit they mention it as a way of ” measur[ing] the effects of aluminium on the disease”.
So, the AA, apparently:

  • acknowledges the follow-ups to a study it completely ignores and
  • thinks it’s a good idea to test a hypothesis that “seems increasingly unlikely”.

Uhm. What about fluorine? It will be the subject of the next post, which will come very, very soon.