Health Stream Article - Issue 28 December 2002
UK Fluoride Research Priorities
The Medical Research Council of the UK has released a Working Group report
on research needs on fluoride and health. The report was commissioned by the
British Department of Health soon after the publication of a review by the University
of York in September 2000(1). This review examined the scientific evidence on
fluoride and health, and concluded that:
· water fluoridation has a beneficial effect on tooth decay
· water fluoridation also increases the prevalence of dental fluorosis
· research carried out on possible non-dental health effects of fluoride
was generally of poor quality and was limited in scope, making it difficult
to interpret the results.
The MRC Working Group was therefore asked to identify and prioritise areas where research was required and where it could usefully inform public health policy, and also to consider how such research might best be undertaken. The Working Group made recommendations in six areas of research:
Total fluoride exposure and uptake
Investigation is needed to determine whether the bioavailability and absorption
of fluoride differs from naturally and artificially fluoridated water, and how
water hardness affects these aspects. If no differences are found between naturally
occurring and artificially added fluoride, then observations of populations
exposed to high levels of natural fluoride in water can provide valid information
on the health effects of artificial fluoridation. However if substantial differences
are found, then specific studies on bioaccumulation of fluoride from artificially
fluoridated water will be required to determine whether this produces a risk
of pathological changes within a reasonable lifespan in more than a small and
defined minority of those exposed.
Better estimates of total dietary fluoride intake and the contribution of fluoridated
water are also needed, as well as fluoride intake from other sources such as
toothpaste. Such studies could be incorporated in the UK National Diet and Nutrition
Survey.
Dental Caries
Studies are required to estimate the effect of fluoridation in children against
a background of widespread use of fluoridated toothpaste, and the impact of
fluoridation on caries occurrence in different social classes. The effects on
recurrent caries in adults and root caries in older adults should also be assessed.
Outcome measures should extend beyond customary measures of decayed, filled
and missing teeth to include effects on quality of life and economic impacts.
Dental Fluorosis
Fluorosis prevalence in fluoridated and non-fluoridated areas needs to be carefully
compared taking into account potential confounding factors and effect modifiers
such as fluoridated toothpaste. Studies should also be undertaken on public
perceptions of dental fluorosis, particularly the distinction between acceptable
and aesthetically unacceptable fluorosis. Any prospective studies of dental
caries incidence that are undertaken should also measure dental fluorosis.
Social Class
Studies on the effect of fluoridation in different social classes should include
assessment of dental caries, dental fluorosis, fluoride from other sources,
and dietary sugar intake.
Bone Health
If naturally and artificially fluoridated water are found to have different
bioavailabilities, then a case-control study should be undertaken on hip fracture
risks after long term exposure to artificially fluoridated water.
Cancer
An updated analysis of UK ecological data on water fluoridation and cancer rates
should be undertaken.
Research on other potential health concerns raised in the literature was considered of low priority by the Working Group, as was research into indirect effects such as impurities in fluoridation chemicals, or leaching of metals from pipes or cooking utensils.
1) Reported in Health Stream Issue 20 - December 2000.