Bone health – no association between fractures and fluoridated water

Bone health studies were analysed by the Australian National Health and Medical Research Council (NHMRC) in its systematic review of water fluoridation published in 2007. (1)

The NHMRC cites three previously conducted systematic reviews of the evidence on fluoride levels in water and the incidence of bone fracture:

• Jones et al (1999), who concluded that water fluoridation levels aimed at preventing dental caries, and possibly at somewhat higher naturally occurring levels, appear to have little effect on fracture risk.

• Demos et al (2001), who concluded that the addition of fluoride to water at approximately 1 ppm does not increase the incidence of fracture and that the body of epidemiological evidence suggests either no association or a slight beneficial effect on bone strength, bone density and fracture risk.

• The York review (2000), which found five studies with a statistically significant reduction in fractures in fluoridated areas, four with an increase and 21 with no effect either way.

Cancer – no pattern of association with fluoridated water

The NHMRC reviewers concurred with the earlier York review’s conclusion that “…there is no clear association between water fluoridation and overall cancer incidence or mortality (for ‘all cause’ cancer, and specifically for bone cancer and osteosarcoma).”

They point out that the York review included 11 studies that found fewer cancers in fluoridated areas, nine studies that found more cancers and two studies that found no difference.

They also point out that a study Smith et al (1980), which was accorded the highest validity score by the York team, showed a reduction of 4.4% in the incidence of cancer in fluoridated areas compared with non-fluoridated areas.

1. National Health and Medical Research Council (2007):  A systematic review of the efficacy and safety of fluoridation.  Australian Government.