Sick to the back teeth

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http://www.guardian.co.uk/medicine/story/0,11381,1357353,00.html

>

> Sick to the back teeth

>

> Are your fillings poisoning you? Peta McGrath investigates the latest

> mercury scare stories

>

> Tuesday November 23, 2004

> The Guardian

>

> Of all substances purported to be responsible for triggering health

> scares,

> mercury does seem to possess an uncanny knack of cropping up more

> frequently

> than most. This week it has once again regained the media spotlight

> because

> of its supposed damaging presence in amalgam fillings. Mary Stephenson, a

> 59-year-old from Hampshire, claims that she was lifted from a 40-year

> black

> hole of depression when 19 silver fillings were removed from her mouth.

> Since a dentist replaced them with white plastic, Stephenson says she is

> " a

> new person " , convinced that mercury poisoning was to blame for her

> illness.

> Whether or not her diagnosis is accurate, its premise is nothing new.

>

> Debate has raged since the 1970s about the potential risks of amalgam

> fillings which contain 52% mercury and 48% copper, zinc and silver.

> Although

> used by dentists for 150 years, mercury's safety had been in doubt ever

> since its use in the preparation of felt hats was blamed for causing St

> Vitus's Dance among hatmakers. Today, a growing band of medical

> professionals link amalgam fillings to conditions ranging from gum

> disease,

> migraine and depression to Alzheimer's, kidney disease and multiple

> sclerosis. Dr Jack Levenson, founder of the British Society for

> Mercury-Free

> Dentistry and co-author of The Menace in Your Mouth, goes as far as

> stating

> that mercury poisoning is an epidemic in the UK. Having removed the

> fillings

> of more than 6,000 patients over the past 20 years, he claims that nearly

> all those he has treated have reported a general improvement in their

> health.

>

> " The British Dental Association's (BDA) figures say 3% of the population

> are particularly sensitive to mercury, but when you have an outbreak of

> flu,

> 0.4% counts as an epidemic, " Levenson says. " I believe that many

> conditions

> fashionably attributed to viruses could in fact be caused by mercury

> toxicity. " He is not alone. Harley Street dentist and president of the

> International Academy of Oral Medicine and Toxicology, Dr Anthony Newbury,

> was among the first UK-based dentists to introduce the idea of a

> mercury-free practice in 1979. He did so after attending a lecture in the

> USA where mercury leakage from fillings was linked, controversially, to

> chronic muscle and joint problems and excessive fatigue. Says Newbury:

> " Everybody knows mercury is toxic, and if they brought it out now for use

> in

> fillings they'd be laughed out of the country. "

>

> Such vociferous campaigning cannot be taken lightly. Mercury is, after

> all,

> known to be the second most toxic metal on the planet after plutonium.

> Most

> dentists, including those who are against an amalgam filling ban, now

> agree

> that the substance does not, as previously believed, become " safely

> sealed "

> when mixed with other metals and that it does have the potential to

> release

> toxic vapours in the mouth, particularly during chewing. Mercury fillings

> are already banned in Sweden, so why not here? It is a question curtly

> dismissed in an official statement distributed by the BDA whenever another

> mercury scare arises. " Each year around nine million fillings are carried

> out in England and Wales alone, yet sensitivity to amalgam is incredibly

> rare, " it reads. " The BDA takes its guidance on the use of amalgam from

> the

> Department of Health's Committee on Toxicology, which has found no reason

> why its use should be withdrawn. "

>

> In the UK, the majority of dentists continue to use amalgam fillings

> because, says Jo Tanner, a BDA spokesperson, " they are hard-wearing,

> long-lasting and relatively cheap compared with plastic ones. " Although it

> is acknowledged that toxic vapours can be released from mercury-containing

> fillings, pro-amalgam experts argue that they are present in minute

> amounts

> and affect those only with an extreme hypersensitivity to mercury. Indeed,

> removing the fillings can cause more vapours to be released than leaving

> them in place. Plenty of research proves they are safe to use, even in

> children. In a study published in the journal Pediatric Dentistry,

> researchers at the University of North Carolina found children were

> unaffected by amalgam fillings and concluded that " very little mercury is

> ever going to be absorbed by the body " .

>

> Were it not for the emergence of potential mercury risks unrelated to

> dentistry, it might indeed be written off as scare-mongering. Yet

> unwelcome

> warnings about mercury poisoning persistently seep in from other avenues

> of

> the medical and scientific professions. In August 2004, a decision was

> made

> to take mercury, a known neurotoxin, out of vaccines given to very young

> British babies following its links with autism. Doctors were told via a

> letter, that despite the Department of Health's instance that thiomersal,

> the form of mercury used in medication, was perfectly safe, it was to be

> phased out of infant vaccinations and replaced by a new 5-in-1 jab. It was

> a

> move welcomed by Professor John Oxford, professor of virology at St

> Bartholemew's Hospital in London, who said that " any doubt whatsoever "

> over

> the safety of mercury should lead to it being removed.

>

> Exposure to mercury in the environment - through food and household

> products - is also consistently highlighted as harmful by some experts. Of

> particular concern is the consumption of seafood and oily fish, both high

> in

> mercury, by vulnerable groups such as women of childbearing age and young

> children. In the environment, mercury is released naturally into the ocean

> through the earth's crust but it is also absorbed into the sea by

> industrial

> pollution. Once present in water it is converted into methyl mercury, a

> more

> toxic form of the substance when eaten by human beings. " Predatory fish at

> the top of the food chain tend to contain much higher levels of mercury

> than

> others - it is stored in the fatty tissue of fish and passed up the food

> chain, " says Dr Hannah Theobald, a nutrition scientist at the British

> Nutrition Foundation. " For that reason, pregnant and breast-feeding women

> and anyone under 16 are now advised not to eat swordfish, sharkfish and

> marlin and should consume only one piece of oily fish, such as mackerel,

> each week. "

>

> But researchers continue to unearth other findings that fuel the mercury

> debate. Following a study in America, the government last year introduced

> precautionary guidelines about the amount of tuna fish consumed by young

> women. Anyone of childbearing age should eat no more than two medium-sized

> cans of tuna or one fresh tuna steak each week - the equivalent of six

> rounds of tuna sandwiches - in order to protect the nervous system of an

> unborn foetus, say government advisers. Mercury levels in the foetal brain

> are up to seven times higher than in maternal blood. " It is thought that a

> woman's blood mercury levels during pregnancy depend partly on how much

> she

> has been exposed to methyl mercury in the months beforehand, " Theobald

> says.

> " It is only advice and people must not assume that the health benefits of

> oily fish, which are immense, don't still hold true for most of us. "

>

> Professor Tom Sanders, of the nutrition department at King's College

> London

> insists the risks of mercury poisoning in the diet remain low and that

> even

> those who eat fish more than once a week are unlikely to be affected. It

> is

> true that, as Sanders claims, evidence against mercury is inconclusive.

> Many, though, remain adamant that the removal of mercury in any form has

> transformed their lives for the better. Ruth Moult, 31, from Somerset, has

> multiple sclerosis but found many of her symptoms improved when three

> leaking mercury fillings were removed. " The effects on my MS have been a

> great improvement in energy levels, regular sleep patterns, a general

> sense

> of well being that I didn't have before, and I no longer have that 'heavy

> legs' feeling, " she says. " Now, I always insist to friends and family not

> to

> have mercury fillings put in their mouths. Standard NHS dentists can

> appear

> exasperated when you ask for a white, but don't let this put you off. "