Community water fluoridation, bone mineral density, and fractures: prospective study of effects in older women
Editorial: Fluoridation, fractures, and teeth
Long term exposure to fluoridation may reduce the risk of fractures of the hip and vertebrae in older women, with enormous importance for improving public health, finds a study in this week's BMJ.
Researchers in the United States identified over 9000 women aged at least 65 years. They compared bone mineral density and fracture rates for 2563 women with no exposure to fluoridated water during the past 20 years and 3218 women with continuous exposure over the same period. They found that women with continuous exposure had a higher bone mineral density at the hip (2.6%) and at the lower spine (2.5%) and had a 31% reduced risk of hip fracture and a 27% reduced risk of vertebral fracture than women with no exposure. The risk of fracture in women with mixed exposure was similar to women with no exposure.
Because the burden of osteoporosis is largely due to fractures of the hip, water fluoridation may be one of the most cost effective methods for reducing these types of fractures, conclude the authors.
In an accompanying editorial, Professor Hannu Hausen at the University of Oulu in Finland, believes that previously some concerns have persisted about possible adverse effects of fluoride on bone. Some earlier studies found higher rates of fractures among communities exposed to fluoridated water, but they failed to account for potential effects of other factors known to be associated with fractures, such as oestrogen use, smoking and body weight, says Hausen. Thus there seems to be reasonably strong evidence that an optimal amount of fluoride in drinking water - either added or occurring naturally - does not increase the risk of osteoporotic fractures in elderly people, which should alleviate remaining concerns about the safety of fluoridation, he adds.
Contacts:
[Paper] Kathy Phipps, Associate Professor, Oregon Health Sciences University, USA
Email: phippsk@ohsu.edu
[Editorial] Professor Hannu Hausen, Institute of Dentistry, University of Oulu, Finland
E-mail: hannu.hausen@oulu.fi