New mercury research "reassuring" to public-but not to me Just the other day (April 18th), I noticed headlines in multiple sources that all basically said the same thing: That mercury-amalgam dental fillings were shown to be safe for children by a pair of recent studies... To this, I say: Put down the pom-poms, parents and dentists. There's reason to be skeptical of . First off, neither of the two studies was very large or tracked subjects for very long (just 7 years was the longest), according to an Associated Press article on the research. One involved 507 8-10 year-olds in Portugal, and the other followed 534 New England kids ages 6-10. Average the two and you've got 520 whole subjects per study. This isn't a sufficiently large sample to gauge the safety of mercury exposure - not by a long shot. Heck, there are this many kids in a typical American elementary school (or close to it). This means that the dental/medical establishment and the media - which should be raising this question themselves, not to mention asking why we're using children as guinea pigs (none of the study kids or their parents were warned of possible dangers beforehand) - is willing to rubber-stamp something as potentially dangerous as mercury ingestion based on a pair of studies no larger than the corner grade school... Reminds me of some drug trials I've heard of. Seriously, you can "prove" the safety (or danger) of just about anything if you study it on a small enough scale. To bring this point home in the mercury debate, do you think studying 520 kids for evidence of autism caused by mercury-based preservatives present in almost all vaccines until recently would yield any meaningful answers? It wouldn't, because autism is relatively rare to begin with-it occurs at a rate of roughly 1 in 500 live births. If one of your study groups of 500 happened to contain a case of autism and the other did not, it would skew the results to an inaccurate conclusion about causation. To be truly valid, I think a study needs to have many more times the number of subjects as the prevalence of the condition being studied. As an example, consider what happened in a Danish study on vaccines and autism. Analysis of 500,000 children showed no link between rates of autism and vaccination. For years, based on SMALLER STUDIES, I believed there was a strong correlation (I even wrote a Daily Dose about it back in 2002), but the inherent credibility of this mammoth study forced me to change my thinking on mercuric vaccine preservatives (but not about vaccines themselves-they're still needless and a health hazard). But I digress... What the media ISN'T reporting along with these 2 studies on mercury amalgam fillings (shocker) is the fact that other studies in the past have pointed to the dangers of these fillings-including one I know of that shows mercury fillings to be the greatest single source of mercury exposure in humans. Keep reading... The research I'm familiar with (see Daily Dose, 9/6/2002 for more details) links the mercury VAPORS emitted by amalgam fillings over a lifetime with disease - especially with autoimmune conditions like Lupus and MS. Another study that bolsters the assertion that inhaled mercury can harm us I reported on June 7th of last year. That research linked atmospheric mercury from coal-fired power plants with dramatically increased rates of autism in children born to mothers in nearby counties... And of course, if you've been a reader of mine for any time at all, you know how I feel about the tragedy of our nation's fisheries. Nowadays, it's widely considered unsafe to eat freshly caught fish in most of America's fresh, estuarine, and even our coastal waters because of the high levels of mercury and other heavy metals in them. As of 2002, 43 of 50 U.S. states have instituted mercury advisories for all or some of their waters. This is a real shame, since fish (especially cold-water varieties like trout and salmon, cod, halibut, and tuna) represent what I consider the single best dietary source of heart-healthy Omega-3 fatty acids. Plus, they're delicious... These two facts - the damning research on inhaled mercury and the mercury crisis in our fisheries - coupled with the surprising Danish study showing no link between injected mercuric compounds and disease make me wonder about something: Could it be that only mercury we absorb environmentally (either by ingestion or inhalation) harms us? Could it be that rates of autism so many argue are connected to mercury in vaccines may actually be caused by mercury absorbed from mothers in vitro? I'll keep you posted on it. Until then, keep eating fish - but only those certified to be caught deep offshore in ocean waters (some labels list this, I'm pretty sure), where concentrations of mercury are lower... And if your child (or grandchild) needs a cavity filled, look into some of the new, mercury-free alternatives. Better safe than sorry, right? Always "filling" you in on the truth, William Campbell Douglass II, MD | 
