There was a very interesting post recently over at Sepp Hasslberger's site about new research that has come out on the effects of fluoride. It's not a very long read--I would encourage you to pop over there and at least scan it.

From the article:

Fluoride accumulates in pineal gland: Fluoride, added to the water supply of many cities and counties and sold by WalMart in its nursery water, has a tendency to accumulate not only in developing teeth causing discoloration, and in bones making them brittle. The mineral is associated with cancer and it also accumulates in the pineal gland, an important hormone control center, where it wreaks considerable havoc. Paul Connett of Fluoride Action Network comments on Jennifer Luke's research which was part of her PhD thesis and had just been published in Caries Research under the title: Fluoride Deposition in the Aged Human Pineal Gland.

Fluoride is a poison, yet we add it to our water and toothpaste and even call it a supplement, although it has no nutritional value. Its medicinal value - the prevention of tooth decay - is the official explanation for adding the toxic mineral to the water supply. But that value is far outweighed by its toxic side effects - amply documented by Paul Connett in his Statement of Concern.

Recent European Union legislation on food supplements lists fluoride as an essential element to offer for supplementation. This is somewhat ironic when contrasted with the European legislators' feigned concern over the putative toxicity of vitamins and their efforts to limit dosages of these vital nutrients in order to "protect public health".