Late last month one of my posts focused on the eating of fish during pregnancy. On the one hand this may be a good idea on the basis that the omega-3 fats certain fish can supply may have benefits for the developing foetus. On the other hand, fish (particularly tuna, marlin and swordfish) can be contaminated with mercury which has the potential to have toxic effects on the nervous system.
Fish is not the only source of mercury. It can also be found in ‘silver’ fillings we may even have in our teeth. In fact, about half of the weight of dental amalgam comes from mercury. I remember some years ago talking to a dentist friend of mine about mercury. He told me that dentists are instructed to treat this substance with extreme caution, especially if there were any ‘spillage’. Just to remind you, this is the same stuff that can end up getting put into our teeth. To my mind, and the minds of some other people too, there’s always been a bit of a ‘disconnect’ here.
Another dentist friend I used to know decided to take some time alongside his professional career to study the health effects of dental amalgam in depth. I remember him telling me that while mercury amalgam was indeed a good material for filling teeth, his view was that it did have the potential to harm health. He didn’t see this as a problem for most individuals with amalgam fillings, though. However, even if only a relatively small percentage of people had problems as a result of their fillings, then the fact that fillings are very common, means that the number of people affected can be considerable.
By way of example, let’s imagine that of the 60 million odd people in the UK, half have at least one mercury amalgam filling. Now, imagine just 1 per cent of these people has a health problem as a result of their filling(s). That equates to 300,000 people (that’s a lot of people).
The reason that I’m writing about this is because for a long time there’s been general resistance from the dental fraternity that mercury fillings may pose a hazard to health. However, there seems to be some reversal in thinking on this as the Food and Drug Administration (FDA) in the USA has very recently published a statement on its website here which raises the issue of the potential for mercury fillings to cause health problems, including neurological problems, in children and foetuses.
This statement includes a link (see here) to a summary of the findings of a panel that looked at this issue in September 2006. After two days of hearings, the panel were asked if the information presented objectively and clearly presented the current state of knowledge about the exposure and health effects related to dental amalgam�? The panel voted ‘no’ to this. The summary states that: Some of the reasons cited by the majority were that the paper was limited and scope and had knowledge gaps particularly regarding exposure limits.�
The panel also concluded that: no conclusion could be drawn regarding the health effects of mercury amalgams because the evidence was often contradictory and that conclusions based on a limited search should not be made.�
Personally, I think it is reassuring that the FDA is taking this issue seriously, and is inviting information and comment that will help it make a proper assessment regarding the impact that mercury fillings may have on health. How refreshing that it recognises that research in the area was inadequate to come to a decision.
As a result, the FDA has re-opened the file, so to speak, and is now engaging in further consultation on this issue. The comment period ends on 28th July 2008, after which the FDA will pronounce again on this issue.
I can’t help notice some parallels here with the potential link between MMR and autism. In particular, while the UK Government and most scientists assert that MMR has been vindicated with regard to autism, research into a potential link (as well as a link between MMR and developmental regression) is still alive in the US. It seems that in the US this issue is not the ‘closed book’ some in the UK believe it to be.
