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By Simon Crompton
Fluoride is good for teeth but it can also be harmful
Like most parents, Beverly Cooke encouraged her daughter Alysia
to use fluoride toothpaste.
From the age
of 18 months Alysia's tooth-cleaning was supervised, and she
never used more than the recommended pea-sized amount of toothpaste.
At nine, Alysia started to have leg pains,
flu-like symptoms and constant headaches. Her condition mystified
specialists until a doctor at an orthopedic clinic noticed
her teeth were mottled brown.
He suspected dental fluorosis,
a condition caused by over-exposure to fluoride that can cause
crumbling of the enamel and permanent damage to teeth.
Tests revealed
high levels of fluoride in Alysia's system,
even though she lived in the Gower Peninsula in Wales, an
area with unfluoridated water. As soon as she stopped using
fluoride toothpaste her symptoms disappeared and now, aged
11, she has problems only if she visits areas where the water
is fluoridated.
Alysia's extreme sensitivity is rare but,
according to the latest evidence, side-effects from fluoride
exposure are not. A government-commissioned study has revealed
that 48 per cent
of children who drink fluoridated water
show signs of fluorosis.
Campaigners and parents are increasingly
angry that the risks are not better publicized. In America,
they point out, there is a mandatory warning on every tube
of fluoridated toothpaste: "In case of accidental ingestion,
seek professional assistance or contact a poison center immediately."
Why are British consumers not given this information? Tony
Lees, from Herefordshire, a dentist for 40 years, believes
that fluoride should be banned from toothpastes and water.
The marginal benefit it displays for teeth does not outweigh
its general dangers, he says.
"In the scale of toxicity, fluorides
fall between arsenic and lead," he says. "Dental
fluorosis is not just a cosmetic problem, but the visible
sign of chronic fluoride poisoning, and children are more
vulnerable than adults."
Anyone overdosing on fluoride, he says,
is in danger of developing chronic skeletal fluorosis, which
can weaken bones and cause arthritis.
Anti-fluoride campaigners have also pointed
to isolated studies and anecdotal evidence indicating that
exposure to fluoride may be linked to thyroid problems, bone
cancers and hip fractures.
"The
danger with toothpaste is that large amounts are easily swallowed,"
says Lees. "This is made worse for children by manufacturers
who give it tempting flavors." But Lees is a lone voice.
Most dentists are convinced that fluoride is good for teeth
and that there is no evidence that it does harm - apart from
the occasional case of cosmetic dental fluorosis. They point
out that in the ten years after fluoride toothpastes were
introduced in 1973, dental disease in children fell so dramatically
that some dentistry schools had to be closed.
Mike Lennon, the Professor of Dental Public
Health at the University of Liverpool and a spokesman for
the British Dental Association, acknowledges that until the
early Nineties some overenthusiastic parents were encouraging
children to use too much fluoride toothpaste.
Toothpaste manufacturers were not taking
into account the tendency of children under the age of two
to swallow everything that goes into their mouths. But now
there are "low-dose" toothpastes for children, and
he believes families in Britain are better educated about
using the right amount.
He thinks that it would be wrong to scare
parents by publicizing the risk of fluorosis or by putting
warnings on tubes. "There is no doubt that fluoride has
a huge benefit. The only risk is dental fluorosis, where you
would have to swallow very high levels, and I know of no evidence
of any risk to health."
The available evidence on the risks and
benefits of fluoride, however, belies the strength of assertion
by both professionals and campaigners, making the correct
course for parents far from clear. A new government-commissioned
study by the University of York on the benefits of water fluoridation
has proved only that existing research - supporting its use
and warning of its dangers - is of such low quality that it
should not dictate policy.
The fact that the British Dental Association
receives money from the toothpaste industry for endorsing
fluoride-based products, among other things, is hardly likely
to inspire confidence. Nor is the organizational quirk, which
means that toothpaste safety is controlled by the body regulating
cosmetics, not medicines.
What everyone
agrees on is that parents should try to ensure that their
child's intake of fluoride is controlled.
In the 10 per cent of Britain where water
is fluoridated, this may mean taking care that a child uses
small amounts of a low-dose children's toothpaste, and steering
clear of fluoride mouthwashes and other products containing
fluoride.
Professor Lennon advises that it is safe
in most areas for children to use a small, pea-sized amount
of the family toothpaste twice a day. "You need to take
advice from your dentist, who will make an assessment of many
factors, including your child's diet and how assiduously you
use toothpaste."
The
Times (UK) May
16, 2001
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