From Mr P. M. Clein, MRPharmS
SIR,—I regret that The Pharmaceutical Journal, a reputable scientific
journal, has fallen for the spin which has been put on the findings of the York
review on water fluoridation (PJ, October 14, p542).
The Phipps report featured, which claims a reduction in fracture risk, was one
of 18 considered by the York review in relation to hip and vertebral fractures,
eight of which supposedly showed a decreased risk and 10 of which purportedly
showed an increased risk. What an astonishing coincidence that this particular
report, graded C (the lowest admissible quality rating) by the York review,
should be published in the BMJ at the same time as the report on the York review,
and given such prominence for a report of questionable quality.
It is also erroneous to imply that dental fluorosis, which according to the
York review affects 48 per cent in fluoridated areas, one in eight severely,
is a mere cosmetic defect only of “aesthetic concern”. It is a sure
sign of fluoride intoxication in a population, as has been admitted in parliamentary
answers by Government ministers. In addition, severe dental fluorosis sometimes
results in tooth loss and often needs expensive treatment with veneers, not
available on the National Health Service, to disguise its disfiguring effects.
The public health White Paper promised a review of the effects of “flouride
on health”. The York terms of reference were narrowed to exclude any studies
(and there were over 3,000 excluded) which did not relate directly to the effects
of fluorinated water only, ie, studies relating to fluoride from other sources,
all animal studies and many statistical studies. In that context, with only
214 animal studies admitted and none of them of high quality, it is hardly surprising
that “no clear evidence” was found of other adverse effects. If you
do not really look for them, you are unlikely to find them.
What this review actually shows is that fluoridation is too risky and that the
48 per cent fluorosis price of a 14.6 per cent caries reduction (not the 50+
per cent reduction claimed before) is too high. We should now have a concerted,
Government-led campaign to tackle the problem of dental caries by other means
involving all health professionals and other agencies, instead of pursuing this
divisive, failed strategy.
Other countries (eg, India, Kenya and China) make strenuous efforts to remove
naturally occurring fluorides from their drinking water because of the proven
long-term deleterious effects on bone. Meanwhile, our Department of Health wants
to put this waste by-product of superphosphate fertiliser manufacture in everyone’s
drinking water for a 15 per cent reduction in dental caries. Frankly, one wouldn’t
give fluoridated water to a dog on the basis of this review.
Paul Clein
Liverpool
On behalf of the authors of the review (Systematic review of water fluoridation,
BMJ 2000;321: 855-9), Dr MARIAN McDONAGH, Professor JOS KLEIJNEN and Mr PAUL
WILSON reply: We do not disagree with Mr Clein that the quality of the evidence
is surprisingly low. However, we would like to clarify and comment on other
points made by him.
We did not state in our BMJ article or our full report that fluorosis was “a
mere cosmetic defect”. The term “aesthetic concern” was used
in our analysis to acknowledge the argument that some mild forms of fluorosis
may not be considered unsightly, to stratify the level of fluorosis that was
considered aesthetically concerning to 12-year old children. In the White Paper,
“Our healthier nation”, the statement that a review would be commissioned
to “carry out an up-to-date, expert scientific review of fluoride and health”
was preceded by the words, “the extensive research linking water fluoridation
to improved dental health was mostly undertaken a few years ago”, clearly
indicating an intention to study the effects of water fluoridation specifically.
We did not narrow the “terms of reference”. We were commissioned to
conduct a systematic review, and in doing so, concentrated on assessing the
best available research evidence to provide the most reliable estimates of benefit
and harm possible. Because animal models do not always predict human experience,
when human data are available, as they are with water fluoridation, these data
are the preferred source of evidence.
Lastly, we would like to point out that although many areas in some countries
do remove fluoride from their water supplies, this is exclusively in the case
where excessively high concentrations of natural fluoride are found (up to 30ppm),
not when the levels are close to 1ppm. Our research now shows that fluorosis
is a dose-dependent phenomenon, which would support this practice.